/* Copyright (C) 2000-2003 MySQL AB This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "mysql_priv.h" #ifdef HAVE_REPLICATION #include #include #include "slave.h" #include "sql_repl.h" #include "repl_failsafe.h" #include #include #include #define MAX_SLAVE_RETRY_PAUSE 5 bool use_slave_mask = 0; MY_BITMAP slave_error_mask; typedef bool (*CHECK_KILLED_FUNC)(THD*,void*); volatile bool slave_sql_running = 0, slave_io_running = 0; char* slave_load_tmpdir = 0; MASTER_INFO *active_mi; HASH replicate_do_table, replicate_ignore_table; DYNAMIC_ARRAY replicate_wild_do_table, replicate_wild_ignore_table; bool do_table_inited = 0, ignore_table_inited = 0; bool wild_do_table_inited = 0, wild_ignore_table_inited = 0; bool table_rules_on= 0, replicate_same_server_id; ulonglong relay_log_space_limit = 0; /* When slave thread exits, we need to remember the temporary tables so we can re-use them on slave start. TODO: move the vars below under MASTER_INFO */ int disconnect_slave_event_count = 0, abort_slave_event_count = 0; int events_till_abort = -1; static int events_till_disconnect = -1; typedef enum { SLAVE_THD_IO, SLAVE_THD_SQL} SLAVE_THD_TYPE; static int process_io_rotate(MASTER_INFO* mi, Rotate_log_event* rev); static int process_io_create_file(MASTER_INFO* mi, Create_file_log_event* cev); static bool wait_for_relay_log_space(RELAY_LOG_INFO* rli); static inline bool io_slave_killed(THD* thd,MASTER_INFO* mi); static inline bool sql_slave_killed(THD* thd,RELAY_LOG_INFO* rli); static int count_relay_log_space(RELAY_LOG_INFO* rli); static int init_slave_thread(THD* thd, SLAVE_THD_TYPE thd_type); static int safe_connect(THD* thd, MYSQL* mysql, MASTER_INFO* mi); static int safe_reconnect(THD* thd, MYSQL* mysql, MASTER_INFO* mi, bool suppress_warnings); static int connect_to_master(THD* thd, MYSQL* mysql, MASTER_INFO* mi, bool reconnect, bool suppress_warnings); static int safe_sleep(THD* thd, int sec, CHECK_KILLED_FUNC thread_killed, void* thread_killed_arg); static int request_table_dump(MYSQL* mysql, const char* db, const char* table); static int create_table_from_dump(THD* thd, MYSQL *mysql, const char* db, const char* table_name, bool overwrite); static int get_master_version_and_clock(MYSQL* mysql, MASTER_INFO* mi); /* Find out which replications threads are running SYNOPSIS init_thread_mask() mask Return value here mi master_info for slave inverse If set, returns which threads are not running IMPLEMENTATION Get a bit mask for which threads are running so that we can later restart these threads. RETURN mask If inverse == 0, running threads If inverse == 1, stopped threads */ void init_thread_mask(int* mask,MASTER_INFO* mi,bool inverse) { bool set_io = mi->slave_running, set_sql = mi->rli.slave_running; register int tmp_mask=0; if (set_io) tmp_mask |= SLAVE_IO; if (set_sql) tmp_mask |= SLAVE_SQL; if (inverse) tmp_mask^= (SLAVE_IO | SLAVE_SQL); *mask = tmp_mask; } /* lock_slave_threads() */ void lock_slave_threads(MASTER_INFO* mi) { //TODO: see if we can do this without dual mutex pthread_mutex_lock(&mi->run_lock); pthread_mutex_lock(&mi->rli.run_lock); } /* unlock_slave_threads() */ void unlock_slave_threads(MASTER_INFO* mi) { //TODO: see if we can do this without dual mutex pthread_mutex_unlock(&mi->rli.run_lock); pthread_mutex_unlock(&mi->run_lock); } /* Initialize slave structures */ int init_slave() { DBUG_ENTER("init_slave"); /* This is called when mysqld starts. Before client connections are accepted. However bootstrap may conflict with us if it does START SLAVE. So it's safer to take the lock. */ pthread_mutex_lock(&LOCK_active_mi); /* TODO: re-write this to interate through the list of files for multi-master */ active_mi= new MASTER_INFO; /* If master_host is not specified, try to read it from the master_info file. If master_host is specified, create the master_info file if it doesn't exists. */ if (!active_mi) { sql_print_error("Failed to allocate memory for the master info structure"); goto err; } if (init_master_info(active_mi,master_info_file,relay_log_info_file, !master_host, (SLAVE_IO | SLAVE_SQL))) { sql_print_error("Failed to initialize the master info structure"); goto err; } if (server_id && !master_host && active_mi->host[0]) master_host= active_mi->host; /* If server id is not set, start_slave_thread() will say it */ if (master_host && !opt_skip_slave_start) { if (start_slave_threads(1 /* need mutex */, 0 /* no wait for start*/, active_mi, master_info_file, relay_log_info_file, SLAVE_IO | SLAVE_SQL)) { sql_print_error("Failed to create slave threads"); goto err; } } pthread_mutex_unlock(&LOCK_active_mi); DBUG_RETURN(0); err: pthread_mutex_unlock(&LOCK_active_mi); DBUG_RETURN(1); } static void free_table_ent(TABLE_RULE_ENT* e) { my_free((gptr) e, MYF(0)); } static byte* get_table_key(TABLE_RULE_ENT* e, uint* len, my_bool not_used __attribute__((unused))) { *len = e->key_len; return (byte*)e->db; } /* Open the given relay log SYNOPSIS init_relay_log_pos() rli Relay information (will be initialized) log Name of relay log file to read from. NULL = First log pos Position in relay log file need_data_lock Set to 1 if this functions should do mutex locks errmsg Store pointer to error message here DESCRIPTION - Close old open relay log files. - If we are using the same relay log as the running IO-thread, then set rli->cur_log to point to the same IO_CACHE entry. - If not, open the 'log' binary file. TODO - check proper initialization of group_master_log_name/group_master_log_pos RETURN VALUES 0 ok 1 error. errmsg is set to point to the error message */ int init_relay_log_pos(RELAY_LOG_INFO* rli,const char* log, ulonglong pos, bool need_data_lock, const char** errmsg) { DBUG_ENTER("init_relay_log_pos"); *errmsg=0; pthread_mutex_t *log_lock=rli->relay_log.get_log_lock(); if (need_data_lock) pthread_mutex_lock(&rli->data_lock); pthread_mutex_lock(log_lock); /* Close log file and free buffers if it's already open */ if (rli->cur_log_fd >= 0) { end_io_cache(&rli->cache_buf); my_close(rli->cur_log_fd, MYF(MY_WME)); rli->cur_log_fd = -1; } rli->group_relay_log_pos = rli->event_relay_log_pos = pos; /* Test to see if the previous run was with the skip of purging If yes, we do not purge when we restart */ if (rli->relay_log.find_log_pos(&rli->linfo, NullS, 1)) { *errmsg="Could not find first log during relay log initialization"; goto err; } if (log && rli->relay_log.find_log_pos(&rli->linfo, log, 1)) { *errmsg="Could not find target log during relay log initialization"; goto err; } strmake(rli->group_relay_log_name,rli->linfo.log_file_name, sizeof(rli->group_relay_log_name)-1); strmake(rli->event_relay_log_name,rli->linfo.log_file_name, sizeof(rli->event_relay_log_name)-1); if (rli->relay_log.is_active(rli->linfo.log_file_name)) { /* The IO thread is using this log file. In this case, we will use the same IO_CACHE pointer to read data as the IO thread is using to write data. */ rli->cur_log= rli->relay_log.get_log_file(); if (my_b_tell(rli->cur_log) == 0 && check_binlog_magic(rli->cur_log, errmsg)) goto err; rli->cur_log_old_open_count=rli->relay_log.get_open_count(); } else { /* Open the relay log and set rli->cur_log to point at this one */ if ((rli->cur_log_fd=open_binlog(&rli->cache_buf, rli->linfo.log_file_name,errmsg)) < 0) goto err; rli->cur_log = &rli->cache_buf; } if (pos >= BIN_LOG_HEADER_SIZE) my_b_seek(rli->cur_log,(off_t)pos); err: /* If we don't purge, we can't honour relay_log_space_limit ; silently discard it */ if (!relay_log_purge) rli->log_space_limit= 0; pthread_cond_broadcast(&rli->data_cond); pthread_mutex_unlock(log_lock); if (need_data_lock) pthread_mutex_unlock(&rli->data_lock); DBUG_RETURN ((*errmsg) ? 1 : 0); } /* Init functio to set up array for errors that should be skipped for slave SYNOPSIS init_slave_skip_errors() arg List of errors numbers to skip, separated with ',' NOTES Called from get_options() in mysqld.cc on start-up */ void init_slave_skip_errors(const char* arg) { const char *p; if (bitmap_init(&slave_error_mask,0,MAX_SLAVE_ERROR,0)) { fprintf(stderr, "Badly out of memory, please check your system status\n"); exit(1); } use_slave_mask = 1; for (;my_isspace(system_charset_info,*arg);++arg) /* empty */; if (!my_strnncoll(system_charset_info,(uchar*)arg,4,(const uchar*)"all",4)) { bitmap_set_all(&slave_error_mask); return; } for (p= arg ; *p; ) { long err_code; if (!(p= str2int(p, 10, 0, LONG_MAX, &err_code))) break; if (err_code < MAX_SLAVE_ERROR) bitmap_set_bit(&slave_error_mask,(uint)err_code); while (!my_isdigit(system_charset_info,*p) && *p) p++; } } void st_relay_log_info::inc_group_relay_log_pos(ulonglong val, ulonglong log_pos, bool skip_lock) { if (!skip_lock) pthread_mutex_lock(&data_lock); inc_event_relay_log_pos(val); group_relay_log_pos= event_relay_log_pos; strmake(group_relay_log_name,event_relay_log_name, sizeof(group_relay_log_name)-1); notify_group_relay_log_name_update(); /* If the slave does not support transactions and replicates a transaction, users should not trust group_master_log_pos (which they can display with SHOW SLAVE STATUS or read from relay-log.info), because to compute group_master_log_pos the slave relies on log_pos stored in the master's binlog, but if we are in a master's transaction these positions are always the BEGIN's one (excepted for the COMMIT), so group_master_log_pos does not advance as it should on the non-transactional slave (it advances by big leaps, whereas it should advance by small leaps). */ if (log_pos) // 3.23 binlogs don't have log_posx { #if MYSQL_VERSION_ID < 50000 /* If the event was converted from a 3.23 format, get_event_len() has grown by 6 bytes (at least for most events, except LOAD DATA INFILE which is already a big problem for 3.23->4.0 replication); 6 bytes is the difference between the header's size in 4.0 (LOG_EVENT_HEADER_LEN) and the header's size in 3.23 (OLD_HEADER_LEN). Note that using mi->old_format will not help if the I/O thread has not started yet. Yes this is a hack but it's just to make 3.23->4.x replication work; 3.23->5.0 replication is working much better. */ group_master_log_pos= log_pos + val - (mi->old_format ? (LOG_EVENT_HEADER_LEN - OLD_HEADER_LEN) : 0); #else group_master_log_pos= log_pos+ val; #endif /* MYSQL_VERSION_ID < 5000 */ } pthread_cond_broadcast(&data_cond); if (!skip_lock) pthread_mutex_unlock(&data_lock); } void st_relay_log_info::close_temporary_tables() { TABLE *table,*next; for (table=save_temporary_tables ; table ; table=next) { next=table->next; /* Don't ask for disk deletion. For now, anyway they will be deleted when slave restarts, but it is a better intention to not delete them. */ close_temporary(table, 0); } save_temporary_tables= 0; slave_open_temp_tables= 0; } /* purge_relay_logs() NOTES Assumes to have a run lock on rli and that no slave thread are running. */ int purge_relay_logs(RELAY_LOG_INFO* rli, THD *thd, bool just_reset, const char** errmsg) { int error=0; DBUG_ENTER("purge_relay_logs"); /* Even if rli->inited==0, we still try to empty rli->master_log_* variables. Indeed, rli->inited==0 does not imply that they already are empty. It could be that slave's info initialization partly succeeded : for example if relay-log.info existed but *relay-bin*.* have been manually removed, init_relay_log_info reads the old relay-log.info and fills rli->master_log_*, then init_relay_log_info checks for the existence of the relay log, this fails and init_relay_log_info leaves rli->inited to 0. In that pathological case, rli->master_log_pos* will be properly reinited at the next START SLAVE (as RESET SLAVE or CHANGE MASTER, the callers of purge_relay_logs, will delete bogus *.info files or replace them with correct files), however if the user does SHOW SLAVE STATUS before START SLAVE, he will see old, confusing rli->master_log_*. In other words, we reinit rli->master_log_* for SHOW SLAVE STATUS to display fine in any case. */ rli->group_master_log_name[0]= 0; rli->group_master_log_pos= 0; if (!rli->inited) { DBUG_PRINT("info", ("rli->inited == 0")); DBUG_RETURN(0); } DBUG_ASSERT(rli->slave_running == 0); DBUG_ASSERT(rli->mi->slave_running == 0); rli->slave_skip_counter=0; pthread_mutex_lock(&rli->data_lock); if (rli->relay_log.reset_logs(thd)) { *errmsg = "Failed during log reset"; error=1; goto err; } /* Save name of used relay log file */ strmake(rli->group_relay_log_name, rli->relay_log.get_log_fname(), sizeof(rli->group_relay_log_name)-1); strmake(rli->event_relay_log_name, rli->relay_log.get_log_fname(), sizeof(rli->event_relay_log_name)-1); // Just first log with magic number and nothing else rli->log_space_total= BIN_LOG_HEADER_SIZE; rli->group_relay_log_pos= rli->event_relay_log_pos= BIN_LOG_HEADER_SIZE; rli->relay_log.reset_bytes_written(); if (!just_reset) error= init_relay_log_pos(rli, rli->group_relay_log_name, rli->group_relay_log_pos, 0 /* do not need data lock */, errmsg); err: #ifndef DBUG_OFF char buf[22]; #endif DBUG_PRINT("info",("log_space_total: %s",llstr(rli->log_space_total,buf))); pthread_mutex_unlock(&rli->data_lock); DBUG_RETURN(error); } int terminate_slave_threads(MASTER_INFO* mi,int thread_mask,bool skip_lock) { if (!mi->inited) return 0; /* successfully do nothing */ int error,force_all = (thread_mask & SLAVE_FORCE_ALL); pthread_mutex_t *sql_lock = &mi->rli.run_lock, *io_lock = &mi->run_lock; pthread_mutex_t *sql_cond_lock,*io_cond_lock; DBUG_ENTER("terminate_slave_threads"); sql_cond_lock=sql_lock; io_cond_lock=io_lock; if (skip_lock) { sql_lock = io_lock = 0; } if ((thread_mask & (SLAVE_IO|SLAVE_FORCE_ALL)) && mi->slave_running) { DBUG_PRINT("info",("Terminating IO thread")); mi->abort_slave=1; if ((error=terminate_slave_thread(mi->io_thd,io_lock, io_cond_lock, &mi->stop_cond, &mi->slave_running)) && !force_all) DBUG_RETURN(error); } if ((thread_mask & (SLAVE_SQL|SLAVE_FORCE_ALL)) && mi->rli.slave_running) { DBUG_PRINT("info",("Terminating SQL thread")); DBUG_ASSERT(mi->rli.sql_thd != 0) ; mi->rli.abort_slave=1; if ((error=terminate_slave_thread(mi->rli.sql_thd,sql_lock, sql_cond_lock, &mi->rli.stop_cond, &mi->rli.slave_running)) && !force_all) DBUG_RETURN(error); } DBUG_RETURN(0); } int terminate_slave_thread(THD* thd, pthread_mutex_t* term_lock, pthread_mutex_t *cond_lock, pthread_cond_t* term_cond, volatile uint *slave_running) { if (term_lock) { pthread_mutex_lock(term_lock); if (!*slave_running) { pthread_mutex_unlock(term_lock); return ER_SLAVE_NOT_RUNNING; } } DBUG_ASSERT(thd != 0); /* Is is criticate to test if the slave is running. Otherwise, we might be referening freed memory trying to kick it */ THD_CHECK_SENTRY(thd); while (*slave_running) // Should always be true { KICK_SLAVE(thd); /* There is a small chance that slave thread might miss the first alarm. To protect againts it, resend the signal until it reacts */ struct timespec abstime; set_timespec(abstime,2); pthread_cond_timedwait(term_cond, cond_lock, &abstime); } if (term_lock) pthread_mutex_unlock(term_lock); return 0; } int start_slave_thread(pthread_handler h_func, pthread_mutex_t *start_lock, pthread_mutex_t *cond_lock, pthread_cond_t *start_cond, volatile uint *slave_running, volatile ulong *slave_run_id, MASTER_INFO* mi, bool high_priority) { pthread_t th; ulong start_id; DBUG_ASSERT(mi->inited); DBUG_ENTER("start_slave_thread"); if (start_lock) pthread_mutex_lock(start_lock); if (!server_id) { if (start_cond) pthread_cond_broadcast(start_cond); if (start_lock) pthread_mutex_unlock(start_lock); sql_print_error("Server id not set, will not start slave"); DBUG_RETURN(ER_BAD_SLAVE); } if (*slave_running) { if (start_cond) pthread_cond_broadcast(start_cond); if (start_lock) pthread_mutex_unlock(start_lock); DBUG_RETURN(ER_SLAVE_MUST_STOP); } start_id= *slave_run_id; DBUG_PRINT("info",("Creating new slave thread")); if (high_priority) my_pthread_attr_setprio(&connection_attrib,CONNECT_PRIOR); if (pthread_create(&th, &connection_attrib, h_func, (void*)mi)) { if (start_lock) pthread_mutex_unlock(start_lock); DBUG_RETURN(ER_SLAVE_THREAD); } if (start_cond && cond_lock) // caller has cond_lock { THD* thd = current_thd; while (start_id == *slave_run_id) { DBUG_PRINT("sleep",("Waiting for slave thread to start")); const char* old_msg = thd->enter_cond(start_cond,cond_lock, "Waiting for slave thread to start"); pthread_cond_wait(start_cond,cond_lock); thd->exit_cond(old_msg); pthread_mutex_lock(cond_lock); // re-acquire it as exit_cond() released if (thd->killed) DBUG_RETURN(ER_SERVER_SHUTDOWN); } } if (start_lock) pthread_mutex_unlock(start_lock); DBUG_RETURN(0); } /* start_slave_threads() NOTES SLAVE_FORCE_ALL is not implemented here on purpose since it does not make sense to do that for starting a slave--we always care if it actually started the threads that were not previously running */ int start_slave_threads(bool need_slave_mutex, bool wait_for_start, MASTER_INFO* mi, const char* master_info_fname, const char* slave_info_fname, int thread_mask) { pthread_mutex_t *lock_io=0,*lock_sql=0,*lock_cond_io=0,*lock_cond_sql=0; pthread_cond_t* cond_io=0,*cond_sql=0; int error=0; DBUG_ENTER("start_slave_threads"); if (need_slave_mutex) { lock_io = &mi->run_lock; lock_sql = &mi->rli.run_lock; } if (wait_for_start) { cond_io = &mi->start_cond; cond_sql = &mi->rli.start_cond; lock_cond_io = &mi->run_lock; lock_cond_sql = &mi->rli.run_lock; } if (thread_mask & SLAVE_IO) error=start_slave_thread(handle_slave_io,lock_io,lock_cond_io, cond_io, &mi->slave_running, &mi->slave_run_id, mi, 1); //high priority, to read the most possible if (!error && (thread_mask & SLAVE_SQL)) { error=start_slave_thread(handle_slave_sql,lock_sql,lock_cond_sql, cond_sql, &mi->rli.slave_running, &mi->rli.slave_run_id, mi, 0); if (error) terminate_slave_threads(mi, thread_mask & SLAVE_IO, 0); } DBUG_RETURN(error); } void init_table_rule_hash(HASH* h, bool* h_inited) { hash_init(h, system_charset_info,TABLE_RULE_HASH_SIZE,0,0, (hash_get_key) get_table_key, (hash_free_key) free_table_ent, 0); *h_inited = 1; } void init_table_rule_array(DYNAMIC_ARRAY* a, bool* a_inited) { my_init_dynamic_array(a, sizeof(TABLE_RULE_ENT*), TABLE_RULE_ARR_SIZE, TABLE_RULE_ARR_SIZE); *a_inited = 1; } static TABLE_RULE_ENT* find_wild(DYNAMIC_ARRAY *a, const char* key, int len) { uint i; const char* key_end = key + len; for (i = 0; i < a->elements; i++) { TABLE_RULE_ENT* e ; get_dynamic(a, (gptr)&e, i); if (!my_wildcmp(system_charset_info, key, key_end, (const char*)e->db, (const char*)(e->db + e->key_len), '\\',wild_one,wild_many)) return e; } return 0; } /* Checks whether tables match some (wild_)do_table and (wild_)ignore_table rules (for replication) SYNOPSIS tables_ok() thd thread (SQL slave thread normally) tables list of tables to check NOTES Note that changing the order of the tables in the list can lead to different results. Note also the order of precedence of the do/ignore rules (see code below). For that reason, users should not set conflicting rules because they may get unpredicted results (precedence order is explained in the manual). RETURN VALUES 0 should not be logged/replicated 1 should be logged/replicated */ bool tables_ok(THD* thd, TABLE_LIST* tables) { bool some_tables_updating= 0; DBUG_ENTER("tables_ok"); for (; tables; tables = tables->next) { char hash_key[2*NAME_LEN+2]; char *end; uint len; if (!tables->updating) continue; some_tables_updating= 1; end= strmov(hash_key, tables->db ? tables->db : thd->db); *end++= '.'; len= (uint) (strmov(end, tables->real_name) - hash_key); if (do_table_inited) // if there are any do's { if (hash_search(&replicate_do_table, (byte*) hash_key, len)) DBUG_RETURN(1); } if (ignore_table_inited) // if there are any ignores { if (hash_search(&replicate_ignore_table, (byte*) hash_key, len)) DBUG_RETURN(0); } if (wild_do_table_inited && find_wild(&replicate_wild_do_table, hash_key, len)) DBUG_RETURN(1); if (wild_ignore_table_inited && find_wild(&replicate_wild_ignore_table, hash_key, len)) DBUG_RETURN(0); } /* If no table was to be updated, ignore statement (no reason we play it on slave, slave is supposed to replicate _changes_ only). If no explicit rule found and there was a do list, do not replicate. If there was no do list, go ahead */ DBUG_RETURN(some_tables_updating && !do_table_inited && !wild_do_table_inited); } /* Checks whether a db matches wild_do_table and wild_ignore_table rules (for replication) SYNOPSIS db_ok_with_wild_table() db name of the db to check. Is tested with check_db_name() before calling this function. NOTES Here is the reason for this function. We advise users who want to exclude a database 'db1' safely to do it with replicate_wild_ignore_table='db1.%' instead of binlog_ignore_db or replicate_ignore_db because the two lasts only check for the selected db, which won't work in that case: USE db2; UPDATE db1.t SET ... #this will be replicated and should not whereas replicate_wild_ignore_table will work in all cases. With replicate_wild_ignore_table, we only check tables. When one does 'DROP DATABASE db1', tables are not involved and the statement will be replicated, while users could expect it would not (as it rougly means 'DROP db1.first_table, DROP db1.second_table...'). In other words, we want to interpret 'db1.%' as "everything touching db1". That is why we want to match 'db1' against 'db1.%' wild table rules. RETURN VALUES 0 should not be logged/replicated 1 should be logged/replicated */ int db_ok_with_wild_table(const char *db) { char hash_key[NAME_LEN+2]; char *end; int len; end= strmov(hash_key, db); *end++= '.'; len= end - hash_key ; if (wild_do_table_inited && find_wild(&replicate_wild_do_table, hash_key, len)) return 1; if (wild_ignore_table_inited && find_wild(&replicate_wild_ignore_table, hash_key, len)) return 0; /* If no explicit rule found and there was a do list, do not replicate. If there was no do list, go ahead */ return !wild_do_table_inited; } int add_table_rule(HASH* h, const char* table_spec) { const char* dot = strchr(table_spec, '.'); if (!dot) return 1; // len is always > 0 because we know the there exists a '.' uint len = (uint)strlen(table_spec); TABLE_RULE_ENT* e = (TABLE_RULE_ENT*)my_malloc(sizeof(TABLE_RULE_ENT) + len, MYF(MY_WME)); if (!e) return 1; e->db = (char*)e + sizeof(TABLE_RULE_ENT); e->tbl_name = e->db + (dot - table_spec) + 1; e->key_len = len; memcpy(e->db, table_spec, len); (void)my_hash_insert(h, (byte*)e); return 0; } /* Add table expression with wildcards to dynamic array */ int add_wild_table_rule(DYNAMIC_ARRAY* a, const char* table_spec) { const char* dot = strchr(table_spec, '.'); if (!dot) return 1; uint len = (uint)strlen(table_spec); TABLE_RULE_ENT* e = (TABLE_RULE_ENT*)my_malloc(sizeof(TABLE_RULE_ENT) + len, MYF(MY_WME)); if (!e) return 1; e->db = (char*)e + sizeof(TABLE_RULE_ENT); e->tbl_name = e->db + (dot - table_spec) + 1; e->key_len = len; memcpy(e->db, table_spec, len); insert_dynamic(a, (gptr)&e); return 0; } static void free_string_array(DYNAMIC_ARRAY *a) { uint i; for (i = 0; i < a->elements; i++) { char* p; get_dynamic(a, (gptr) &p, i); my_free(p, MYF(MY_WME)); } delete_dynamic(a); } #ifdef NOT_USED_YET static int end_slave_on_walk(MASTER_INFO* mi, gptr /*unused*/) { end_master_info(mi); return 0; } #endif /* Free all resources used by slave SYNOPSIS end_slave() */ void end_slave() { /* This is called when the server terminates, in close_connections(). It terminates slave threads. However, some CHANGE MASTER etc may still be running presently. If a START SLAVE was in progress, the mutex lock below will make us wait until slave threads have started, and START SLAVE returns, then we terminate them here. */ pthread_mutex_lock(&LOCK_active_mi); if (active_mi) { /* TODO: replace the line below with list_walk(&master_list, (list_walk_action)end_slave_on_walk,0); once multi-master code is ready. */ terminate_slave_threads(active_mi,SLAVE_FORCE_ALL); end_master_info(active_mi); if (do_table_inited) hash_free(&replicate_do_table); if (ignore_table_inited) hash_free(&replicate_ignore_table); if (wild_do_table_inited) free_string_array(&replicate_wild_do_table); if (wild_ignore_table_inited) free_string_array(&replicate_wild_ignore_table); delete active_mi; active_mi= 0; } pthread_mutex_unlock(&LOCK_active_mi); } static bool io_slave_killed(THD* thd, MASTER_INFO* mi) { DBUG_ASSERT(mi->io_thd == thd); DBUG_ASSERT(mi->slave_running); // tracking buffer overrun return mi->abort_slave || abort_loop || thd->killed; } static bool sql_slave_killed(THD* thd, RELAY_LOG_INFO* rli) { DBUG_ASSERT(rli->sql_thd == thd); DBUG_ASSERT(rli->slave_running == 1);// tracking buffer overrun return rli->abort_slave || abort_loop || thd->killed; } /* Writes an error message to rli->last_slave_error and rli->last_slave_errno (which will be displayed by SHOW SLAVE STATUS), and prints it to stderr. SYNOPSIS slave_print_error() rli err_code The error code msg The error message (usually related to the error code, but can contain more information). ... (this is printf-like format, with % symbols in msg) RETURN VALUES void */ void slave_print_error(RELAY_LOG_INFO* rli, int err_code, const char* msg, ...) { va_list args; va_start(args,msg); my_vsnprintf(rli->last_slave_error, sizeof(rli->last_slave_error), msg, args); rli->last_slave_errno = err_code; /* If the error string ends with '.', do not add a ',' it would be ugly */ if (rli->last_slave_error[0] && (*(strend(rli->last_slave_error)-1) == '.')) sql_print_error("Slave: %s Error_code: %d", rli->last_slave_error, err_code); else sql_print_error("Slave: %s, Error_code: %d", rli->last_slave_error, err_code); } /* skip_load_data_infile() NOTES This is used to tell a 3.23 master to break send_file() */ void skip_load_data_infile(NET *net) { (void)net_request_file(net, "/dev/null"); (void)my_net_read(net); // discard response (void)net_write_command(net, 0, "", 0, "", 0); // Send ok } bool net_request_file(NET* net, const char* fname) { DBUG_ENTER("net_request_file"); DBUG_RETURN(net_write_command(net, 251, fname, strlen(fname), "", 0)); } const char *rewrite_db(const char* db, uint32 *new_len) { if (replicate_rewrite_db.is_empty() || !db) return db; I_List_iterator it(replicate_rewrite_db); i_string_pair* tmp; while ((tmp=it++)) { if (!strcmp(tmp->key, db)) { *new_len= (uint32)strlen(tmp->val); return tmp->val; } } return db; } /* From other comments and tests in code, it looks like sometimes Query_log_event and Load_log_event can have db == 0 (see rewrite_db() above for example) (cases where this happens are unclear; it may be when the master is 3.23). */ const char *print_slave_db_safe(const char* db) { return (db ? db : ""); } /* Checks whether a db matches some do_db and ignore_db rules (for logging or replication) SYNOPSIS db_ok() db name of the db to check do_list either binlog_do_db or replicate_do_db ignore_list either binlog_ignore_db or replicate_ignore_db RETURN VALUES 0 should not be logged/replicated 1 should be logged/replicated */ int db_ok(const char* db, I_List &do_list, I_List &ignore_list ) { if (do_list.is_empty() && ignore_list.is_empty()) return 1; // ok to replicate if the user puts no constraints /* If the user has specified restrictions on which databases to replicate and db was not selected, do not replicate. */ if (!db) return 0; if (!do_list.is_empty()) // if the do's are not empty { I_List_iterator it(do_list); i_string* tmp; while ((tmp=it++)) { if (!strcmp(tmp->ptr, db)) return 1; // match } return 0; } else // there are some elements in the don't, otherwise we cannot get here { I_List_iterator it(ignore_list); i_string* tmp; while ((tmp=it++)) { if (!strcmp(tmp->ptr, db)) return 0; // match } return 1; } } static int init_strvar_from_file(char *var, int max_size, IO_CACHE *f, const char *default_val) { uint length; if ((length=my_b_gets(f,var, max_size))) { char* last_p = var + length -1; if (*last_p == '\n') *last_p = 0; // if we stopped on newline, kill it else { /* If we truncated a line or stopped on last char, remove all chars up to and including newline. */ int c; while (((c=my_b_get(f)) != '\n' && c != my_b_EOF)); } return 0; } else if (default_val) { strmake(var, default_val, max_size-1); return 0; } return 1; } static int init_intvar_from_file(int* var, IO_CACHE* f, int default_val) { char buf[32]; if (my_b_gets(f, buf, sizeof(buf))) { *var = atoi(buf); return 0; } else if (default_val) { *var = default_val; return 0; } return 1; } static int get_master_version_and_clock(MYSQL* mysql, MASTER_INFO* mi) { const char* errmsg= 0; /* Note the following switch will bug when we have MySQL branch 30 ;) */ switch (*mysql->server_version) { case '3': mi->old_format = (strncmp(mysql->server_version, "3.23.57", 7) < 0) /* < .57 */ ? BINLOG_FORMAT_323_LESS_57 : BINLOG_FORMAT_323_GEQ_57 ; break; case '4': mi->old_format = BINLOG_FORMAT_CURRENT; break; default: /* 5.0 is not supported */ errmsg = "Master reported an unrecognized MySQL version. Note that 4.1 \ slaves can't replicate a 5.0 or newer master."; break; } /* Compare the master and slave's clock. Do not die if master's clock is unavailable (very old master not supporting UNIX_TIMESTAMP()?). */ MYSQL_RES *master_res= 0; MYSQL_ROW master_row; if (!mysql_real_query(mysql, "SELECT UNIX_TIMESTAMP()", 23) && (master_res= mysql_store_result(mysql)) && (master_row= mysql_fetch_row(master_res))) { mi->clock_diff_with_master= (long) (time((time_t*) 0) - strtoul(master_row[0], 0, 10)); } else { mi->clock_diff_with_master= 0; /* The "most sensible" value */ sql_print_warning("\"SELECT UNIX_TIMESTAMP()\" failed on master, \ do not trust column Seconds_Behind_Master of SHOW SLAVE STATUS"); } if (master_res) mysql_free_result(master_res); /* Check that the master's server id and ours are different. Because if they are equal (which can result from a simple copy of master's datadir to slave, thus copying some my.cnf), replication will work but all events will be skipped. Do not die if SHOW VARIABLES LIKE 'SERVER_ID' fails on master (very old master?). Note: we could have put a @@SERVER_ID in the previous SELECT UNIX_TIMESTAMP() instead, but this would not have worked on 3.23 masters. */ if (!mysql_real_query(mysql, "SHOW VARIABLES LIKE 'SERVER_ID'", 31) && (master_res= mysql_store_result(mysql))) { if ((master_row= mysql_fetch_row(master_res)) && (::server_id == strtoul(master_row[1], 0, 10)) && !replicate_same_server_id) errmsg= "The slave I/O thread stops because master and slave have equal \ MySQL server ids; these ids must be different for replication to work (or \ the --replicate-same-server-id option must be used on slave but this does \ not always make sense; please check the manual before using it)."; mysql_free_result(master_res); } /* Check that the master's global character_set_server and ours are the same. Not fatal if query fails (old master?). Note that we don't check for equality of global character_set_client and collation_connection (neither do we prevent their setting in set_var.cc). That's because from what I (Guilhem) have tested, the global values of these 2 are never used (new connections don't use them). We don't test equality of global collation_database either as it's is going to be deprecated (made read-only) in 4.1 very soon. We don't do it for <3.23.57 because masters <3.23.50 hang on SELECT @@unknown_var (BUG#7965 - see changelog of 3.23.50). */ if (mi->old_format == BINLOG_FORMAT_323_LESS_57) goto err; if (!mysql_real_query(mysql, "SELECT @@GLOBAL.COLLATION_SERVER", 32) && (master_res= mysql_store_result(mysql))) { if ((master_row= mysql_fetch_row(master_res)) && strcmp(master_row[0], global_system_variables.collation_server->name)) errmsg= "The slave I/O thread stops because master and slave have \ different values for the COLLATION_SERVER global variable. The values must \ be equal for replication to work"; mysql_free_result(master_res); } /* Perform analogous check for time zone. Theoretically we also should perform check here to verify that SYSTEM time zones are the same on slave and master, but we can't rely on value of @@system_time_zone variable (it is time zone abbreviation) since it determined at start time and so could differ for slave and master even if they are really in the same system time zone. So we are omiting this check and just relying on documentation. Also according to Monty there are many users who are using replication between servers in various time zones. Hence such check will broke everything for them. (And now everything will work for them because by default both their master and slave will have 'SYSTEM' time zone). */ if (!mysql_real_query(mysql, "SELECT @@GLOBAL.TIME_ZONE", 25) && (master_res= mysql_store_result(mysql))) { if ((master_row= mysql_fetch_row(master_res)) && strcmp(master_row[0], global_system_variables.time_zone->get_name()->ptr())) errmsg= "The slave I/O thread stops because master and slave have \ different values for the TIME_ZONE global variable. The values must \ be equal for replication to work"; mysql_free_result(master_res); } err: if (errmsg) { sql_print_error(errmsg); return 1; } return 0; } /* Used by fetch_master_table (used by LOAD TABLE tblname FROM MASTER and LOAD DATA FROM MASTER). Drops the table (if 'overwrite' is true) and recreates it from the dump. Honours replication inclusion/exclusion rules. db must be non-zero (guarded by assertion). RETURN VALUES 0 success 1 error */ static int create_table_from_dump(THD* thd, MYSQL *mysql, const char* db, const char* table_name, bool overwrite) { ulong packet_len; char *query, *save_db; uint32 save_db_length; Vio* save_vio; HA_CHECK_OPT check_opt; TABLE_LIST tables; int error= 1; handler *file; ulong save_options; NET *net= &mysql->net; DBUG_ENTER("create_table_from_dump"); packet_len= my_net_read(net); // read create table statement if (packet_len == packet_error) { send_error(thd, ER_MASTER_NET_READ); DBUG_RETURN(1); } if (net->read_pos[0] == 255) // error from master { char *err_msg; err_msg= (char*) net->read_pos + ((mysql->server_capabilities & CLIENT_PROTOCOL_41) ? 3+SQLSTATE_LENGTH+1 : 3); net_printf(thd, ER_MASTER, err_msg); DBUG_RETURN(1); } thd->command = COM_TABLE_DUMP; thd->query_length= packet_len; /* Note that we should not set thd->query until the area is initalized */ if (!(query = thd->strmake((char*) net->read_pos, packet_len))) { sql_print_error("create_table_from_dump: out of memory"); net_printf(thd, ER_GET_ERRNO, "Out of memory"); DBUG_RETURN(1); } thd->query= query; thd->query_error = 0; thd->net.no_send_ok = 1; bzero((char*) &tables,sizeof(tables)); tables.db = (char*)db; tables.alias= tables.real_name= (char*)table_name; /* Drop the table if 'overwrite' is true */ if (overwrite && mysql_rm_table(thd,&tables,1,0)) /* drop if exists */ { send_error(thd); sql_print_error("create_table_from_dump: failed to drop the table"); goto err; } /* Create the table. We do not want to log the "create table" statement */ save_options = thd->options; thd->options &= ~(ulong) (OPTION_BIN_LOG); thd->proc_info = "Creating table from master dump"; // save old db in case we are creating in a different database save_db = thd->db; save_db_length= thd->db_length; thd->db = (char*)db; DBUG_ASSERT(thd->db); thd->db_length= strlen(thd->db); mysql_parse(thd, thd->query, packet_len); // run create table thd->db = save_db; // leave things the way the were before thd->db_length= save_db_length; thd->options = save_options; if (thd->query_error) goto err; // mysql_parse took care of the error send thd->proc_info = "Opening master dump table"; tables.lock_type = TL_WRITE; if (!open_ltable(thd, &tables, TL_WRITE)) { send_error(thd,0,0); // Send error from open_ltable sql_print_error("create_table_from_dump: could not open created table"); goto err; } file = tables.table->file; thd->proc_info = "Reading master dump table data"; /* Copy the data file */ if (file->net_read_dump(net)) { net_printf(thd, ER_MASTER_NET_READ); sql_print_error("create_table_from_dump: failed in\ handler::net_read_dump()"); goto err; } check_opt.init(); check_opt.flags|= T_VERY_SILENT | T_CALC_CHECKSUM | T_QUICK; thd->proc_info = "Rebuilding the index on master dump table"; /* We do not want repair() to spam us with messages just send them to the error log, and report the failure in case of problems. */ save_vio = thd->net.vio; thd->net.vio = 0; /* Rebuild the index file from the copied data file (with REPAIR) */ error=file->repair(thd,&check_opt) != 0; thd->net.vio = save_vio; if (error) net_printf(thd, ER_INDEX_REBUILD,tables.table->real_name); err: close_thread_tables(thd); thd->net.no_send_ok = 0; DBUG_RETURN(error); } int fetch_master_table(THD *thd, const char *db_name, const char *table_name, MASTER_INFO *mi, MYSQL *mysql, bool overwrite) { int error= 1; const char *errmsg=0; bool called_connected= (mysql != NULL); DBUG_ENTER("fetch_master_table"); DBUG_PRINT("enter", ("db_name: '%s' table_name: '%s'", db_name,table_name)); if (!called_connected) { if (!(mysql = mysql_init(NULL))) { send_error(thd); // EOM DBUG_RETURN(1); } if (connect_to_master(thd, mysql, mi)) { net_printf(thd, ER_CONNECT_TO_MASTER, mysql_error(mysql)); mysql_close(mysql); DBUG_RETURN(1); } if (thd->killed) goto err; } if (request_table_dump(mysql, db_name, table_name)) { error= ER_UNKNOWN_ERROR; errmsg= "Failed on table dump request"; goto err; } if (create_table_from_dump(thd, mysql, db_name, table_name, overwrite)) goto err; // create_table_from_dump have sent the error already error = 0; err: thd->net.no_send_ok = 0; // Clear up garbage after create_table_from_dump if (!called_connected) mysql_close(mysql); if (errmsg && thd->vio_ok()) send_error(thd, error, errmsg); DBUG_RETURN(test(error)); // Return 1 on error } void end_master_info(MASTER_INFO* mi) { DBUG_ENTER("end_master_info"); if (!mi->inited) DBUG_VOID_RETURN; end_relay_log_info(&mi->rli); if (mi->fd >= 0) { end_io_cache(&mi->file); (void)my_close(mi->fd, MYF(MY_WME)); mi->fd = -1; } mi->inited = 0; DBUG_VOID_RETURN; } int init_relay_log_info(RELAY_LOG_INFO* rli, const char* info_fname) { char fname[FN_REFLEN+128]; int info_fd; const char* msg = 0; int error = 0; DBUG_ENTER("init_relay_log_info"); if (rli->inited) // Set if this function called DBUG_RETURN(0); fn_format(fname, info_fname, mysql_data_home, "", 4+32); pthread_mutex_lock(&rli->data_lock); info_fd = rli->info_fd; rli->cur_log_fd = -1; rli->slave_skip_counter=0; rli->abort_pos_wait=0; rli->log_space_limit= relay_log_space_limit; rli->log_space_total= 0; // TODO: make this work with multi-master if (!opt_relay_logname) { char tmp[FN_REFLEN]; /* TODO: The following should be using fn_format(); We just need to first change fn_format() to cut the file name if it's too long. */ strmake(tmp,glob_hostname,FN_REFLEN-5); strmov(strcend(tmp,'.'),"-relay-bin"); opt_relay_logname=my_strdup(tmp,MYF(MY_WME)); } /* The relay log will now be opened, as a SEQ_READ_APPEND IO_CACHE. Note that the I/O thread flushes it to disk after writing every event, in flush_master_info(mi, 1). */ /* For the maximum log size, we choose max_relay_log_size if it is non-zero, max_binlog_size otherwise. If later the user does SET GLOBAL on one of these variables, fix_max_binlog_size and fix_max_relay_log_size will reconsider the choice (for example if the user changes max_relay_log_size to zero, we have to switch to using max_binlog_size for the relay log) and update rli->relay_log.max_size (and mysql_bin_log.max_size). */ if (open_log(&rli->relay_log, glob_hostname, opt_relay_logname, "-relay-bin", opt_relaylog_index_name, LOG_BIN, 1 /* read_append cache */, 1 /* no auto events */, max_relay_log_size ? max_relay_log_size : max_binlog_size)) { pthread_mutex_unlock(&rli->data_lock); sql_print_error("Failed in open_log() called from init_relay_log_info()"); DBUG_RETURN(1); } /* if file does not exist */ if (access(fname,F_OK)) { /* If someone removed the file from underneath our feet, just close the old descriptor and re-create the old file */ if (info_fd >= 0) my_close(info_fd, MYF(MY_WME)); if ((info_fd = my_open(fname, O_CREAT|O_RDWR|O_BINARY, MYF(MY_WME))) < 0) { sql_print_error("Failed to create a new relay log info file (\ file '%s', errno %d)", fname, my_errno); msg= current_thd->net.last_error; goto err; } if (init_io_cache(&rli->info_file, info_fd, IO_SIZE*2, READ_CACHE, 0L,0, MYF(MY_WME))) { sql_print_error("Failed to create a cache on relay log info file '%s'", fname); msg= current_thd->net.last_error; goto err; } /* Init relay log with first entry in the relay index file */ if (init_relay_log_pos(rli,NullS,BIN_LOG_HEADER_SIZE,0 /* no data lock */, &msg)) { sql_print_error("Failed to open the relay log 'FIRST' (relay_log_pos 4)"); goto err; } rli->group_master_log_name[0]= 0; rli->group_master_log_pos= 0; rli->info_fd= info_fd; } else // file exists { if (info_fd >= 0) reinit_io_cache(&rli->info_file, READ_CACHE, 0L,0,0); else { int error=0; if ((info_fd = my_open(fname, O_RDWR|O_BINARY, MYF(MY_WME))) < 0) { sql_print_error("\ Failed to open the existing relay log info file '%s' (errno %d)", fname, my_errno); error= 1; } else if (init_io_cache(&rli->info_file, info_fd, IO_SIZE*2, READ_CACHE, 0L, 0, MYF(MY_WME))) { sql_print_error("Failed to create a cache on relay log info file '%s'", fname); error= 1; } if (error) { if (info_fd >= 0) my_close(info_fd, MYF(0)); rli->info_fd= -1; rli->relay_log.close(LOG_CLOSE_INDEX | LOG_CLOSE_STOP_EVENT); pthread_mutex_unlock(&rli->data_lock); DBUG_RETURN(1); } } rli->info_fd = info_fd; int relay_log_pos, master_log_pos; if (init_strvar_from_file(rli->group_relay_log_name, sizeof(rli->group_relay_log_name), &rli->info_file, "") || init_intvar_from_file(&relay_log_pos, &rli->info_file, BIN_LOG_HEADER_SIZE) || init_strvar_from_file(rli->group_master_log_name, sizeof(rli->group_master_log_name), &rli->info_file, "") || init_intvar_from_file(&master_log_pos, &rli->info_file, 0)) { msg="Error reading slave log configuration"; goto err; } strmake(rli->event_relay_log_name,rli->group_relay_log_name, sizeof(rli->event_relay_log_name)-1); rli->group_relay_log_pos= rli->event_relay_log_pos= relay_log_pos; rli->group_master_log_pos= master_log_pos; if (init_relay_log_pos(rli, rli->group_relay_log_name, rli->group_relay_log_pos, 0 /* no data lock*/, &msg)) { char llbuf[22]; sql_print_error("Failed to open the relay log '%s' (relay_log_pos %s)", rli->group_relay_log_name, llstr(rli->group_relay_log_pos, llbuf)); goto err; } } DBUG_ASSERT(rli->event_relay_log_pos >= BIN_LOG_HEADER_SIZE); DBUG_ASSERT(my_b_tell(rli->cur_log) == rli->event_relay_log_pos); /* Now change the cache from READ to WRITE - must do this before flush_relay_log_info */ reinit_io_cache(&rli->info_file, WRITE_CACHE,0L,0,1); if ((error= flush_relay_log_info(rli))) sql_print_error("Failed to flush relay log info file"); if (count_relay_log_space(rli)) { msg="Error counting relay log space"; goto err; } rli->inited= 1; pthread_mutex_unlock(&rli->data_lock); DBUG_RETURN(error); err: sql_print_error(msg); end_io_cache(&rli->info_file); if (info_fd >= 0) my_close(info_fd, MYF(0)); rli->info_fd= -1; rli->relay_log.close(LOG_CLOSE_INDEX | LOG_CLOSE_STOP_EVENT); pthread_mutex_unlock(&rli->data_lock); DBUG_RETURN(1); } static inline int add_relay_log(RELAY_LOG_INFO* rli,LOG_INFO* linfo) { MY_STAT s; DBUG_ENTER("add_relay_log"); if (!my_stat(linfo->log_file_name,&s,MYF(0))) { sql_print_error("log %s listed in the index, but failed to stat", linfo->log_file_name); DBUG_RETURN(1); } rli->log_space_total += s.st_size; #ifndef DBUG_OFF char buf[22]; DBUG_PRINT("info",("log_space_total: %s", llstr(rli->log_space_total,buf))); #endif DBUG_RETURN(0); } static bool wait_for_relay_log_space(RELAY_LOG_INFO* rli) { bool slave_killed=0; MASTER_INFO* mi = rli->mi; const char *save_proc_info; THD* thd = mi->io_thd; DBUG_ENTER("wait_for_relay_log_space"); pthread_mutex_lock(&rli->log_space_lock); save_proc_info= thd->enter_cond(&rli->log_space_cond, &rli->log_space_lock, "\ Waiting for the slave SQL thread to free enough relay log space"); while (rli->log_space_limit < rli->log_space_total && !(slave_killed=io_slave_killed(thd,mi)) && !rli->ignore_log_space_limit) pthread_cond_wait(&rli->log_space_cond, &rli->log_space_lock); thd->exit_cond(save_proc_info); DBUG_RETURN(slave_killed); } static int count_relay_log_space(RELAY_LOG_INFO* rli) { LOG_INFO linfo; DBUG_ENTER("count_relay_log_space"); rli->log_space_total= 0; if (rli->relay_log.find_log_pos(&linfo, NullS, 1)) { sql_print_error("Could not find first log while counting relay log space"); DBUG_RETURN(1); } do { if (add_relay_log(rli,&linfo)) DBUG_RETURN(1); } while (!rli->relay_log.find_next_log(&linfo, 1)); /* As we have counted everything, including what may have written in a preceding write, we must reset bytes_written, or we may count some space twice. */ rli->relay_log.reset_bytes_written(); DBUG_RETURN(0); } /* Builds a Rotate from the ignored events' info and writes it to relay log. SYNOPSIS write_ignored_events_info_to_relay_log() thd pointer to I/O thread's thd mi DESCRIPTION Slave I/O thread, going to die, must leave a durable trace of the ignored events' end position for the use of the slave SQL thread, by calling this function. Only that thread can call it (see assertion). */ static void write_ignored_events_info_to_relay_log(THD *thd, MASTER_INFO *mi) { RELAY_LOG_INFO *rli= &mi->rli; pthread_mutex_t *log_lock= rli->relay_log.get_log_lock(); DBUG_ASSERT(thd == mi->io_thd); pthread_mutex_lock(log_lock); if (rli->ign_master_log_name_end[0]) { DBUG_PRINT("info",("writing a Rotate event to track down ignored events")); Rotate_log_event *ev= new Rotate_log_event(thd, rli->ign_master_log_name_end, 0, rli->ign_master_log_pos_end, Rotate_log_event::DUP_NAME); rli->ign_master_log_name_end[0]= 0; /* can unlock before writing as slave SQL thd will soon see our Rotate */ pthread_mutex_unlock(log_lock); if (likely((bool)ev)) { ev->server_id= 0; // don't be ignored by slave SQL thread if (unlikely(rli->relay_log.append(ev))) sql_print_error("Slave I/O thread failed to write a Rotate event" " to the relay log, " "SHOW SLAVE STATUS may be inaccurate"); rli->relay_log.harvest_bytes_written(&rli->log_space_total); flush_master_info(mi, 1); delete ev; } else sql_print_error("Slave I/O thread failed to create a Rotate event" " (out of memory?), " "SHOW SLAVE STATUS may be inaccurate"); } else pthread_mutex_unlock(log_lock); } void init_master_info_with_options(MASTER_INFO* mi) { mi->master_log_name[0] = 0; mi->master_log_pos = BIN_LOG_HEADER_SIZE; // skip magic number if (master_host) strmake(mi->host, master_host, sizeof(mi->host) - 1); if (master_user) strmake(mi->user, master_user, sizeof(mi->user) - 1); if (master_password) strmake(mi->password, master_password, MAX_PASSWORD_LENGTH); mi->port = master_port; mi->connect_retry = master_connect_retry; mi->ssl= master_ssl; if (master_ssl_ca) strmake(mi->ssl_ca, master_ssl_ca, sizeof(mi->ssl_ca)-1); if (master_ssl_capath) strmake(mi->ssl_capath, master_ssl_capath, sizeof(mi->ssl_capath)-1); if (master_ssl_cert) strmake(mi->ssl_cert, master_ssl_cert, sizeof(mi->ssl_cert)-1); if (master_ssl_cipher) strmake(mi->ssl_cipher, master_ssl_cipher, sizeof(mi->ssl_cipher)-1); if (master_ssl_key) strmake(mi->ssl_key, master_ssl_key, sizeof(mi->ssl_key)-1); } void clear_slave_error(RELAY_LOG_INFO* rli) { /* Clear the errors displayed by SHOW SLAVE STATUS */ rli->last_slave_error[0]= 0; rli->last_slave_errno= 0; } /* Reset UNTIL condition for RELAY_LOG_INFO SYNOPSYS clear_until_condition() rli - RELAY_LOG_INFO structure where UNTIL condition should be reset */ void clear_until_condition(RELAY_LOG_INFO* rli) { rli->until_condition= RELAY_LOG_INFO::UNTIL_NONE; rli->until_log_name[0]= 0; rli->until_log_pos= 0; } #define LINES_IN_MASTER_INFO_WITH_SSL 14 int init_master_info(MASTER_INFO* mi, const char* master_info_fname, const char* slave_info_fname, bool abort_if_no_master_info_file, int thread_mask) { int fd,error; char fname[FN_REFLEN+128]; DBUG_ENTER("init_master_info"); if (mi->inited) { /* We have to reset read position of relay-log-bin as we may have already been reading from 'hotlog' when the slave was stopped last time. If this case pos_in_file would be set and we would get a crash when trying to read the signature for the binary relay log. We only rewind the read position if we are starting the SQL thread. The handle_slave_sql thread assumes that the read position is at the beginning of the file, and will read the "signature" and then fast-forward to the last position read. */ if (thread_mask & SLAVE_SQL) { my_b_seek(mi->rli.cur_log, (my_off_t) 0); } DBUG_RETURN(0); } mi->mysql=0; mi->file_id=1; fn_format(fname, master_info_fname, mysql_data_home, "", 4+32); /* We need a mutex while we are changing master info parameters to keep other threads from reading bogus info */ pthread_mutex_lock(&mi->data_lock); fd = mi->fd; /* does master.info exist ? */ if (access(fname,F_OK)) { if (abort_if_no_master_info_file) { pthread_mutex_unlock(&mi->data_lock); DBUG_RETURN(0); } /* if someone removed the file from underneath our feet, just close the old descriptor and re-create the old file */ if (fd >= 0) my_close(fd, MYF(MY_WME)); if ((fd = my_open(fname, O_CREAT|O_RDWR|O_BINARY, MYF(MY_WME))) < 0 ) { sql_print_error("Failed to create a new master info file (\ file '%s', errno %d)", fname, my_errno); goto err; } if (init_io_cache(&mi->file, fd, IO_SIZE*2, READ_CACHE, 0L,0, MYF(MY_WME))) { sql_print_error("Failed to create a cache on master info file (\ file '%s')", fname); goto err; } mi->fd = fd; init_master_info_with_options(mi); } else // file exists { if (fd >= 0) reinit_io_cache(&mi->file, READ_CACHE, 0L,0,0); else { if ((fd = my_open(fname, O_RDWR|O_BINARY, MYF(MY_WME))) < 0 ) { sql_print_error("Failed to open the existing master info file (\ file '%s', errno %d)", fname, my_errno); goto err; } if (init_io_cache(&mi->file, fd, IO_SIZE*2, READ_CACHE, 0L, 0, MYF(MY_WME))) { sql_print_error("Failed to create a cache on master info file (\ file '%s')", fname); goto err; } } mi->fd = fd; int port, connect_retry, master_log_pos, ssl= 0, lines; char *first_non_digit; /* Starting from 4.1.x master.info has new format. Now its first line contains number of lines in file. By reading this number we will be always distinguish to which version our master.info corresponds to. We can't simply count lines in file since versions before 4.1.x could generate files with more lines than needed. If first line doesn't contain a number or contain number less than 14 then such file is treated like file from pre 4.1.1 version. There is no ambiguity when reading an old master.info, as before 4.1.1, the first line contained the binlog's name, which is either empty or has an extension (contains a '.'), so can't be confused with an integer. So we're just reading first line and trying to figure which version is this. */ /* The first row is temporarily stored in mi->master_log_name, if it is line count and not binlog name (new format) it will be overwritten by the second row later. */ if (init_strvar_from_file(mi->master_log_name, sizeof(mi->master_log_name), &mi->file, "")) goto errwithmsg; lines= strtoul(mi->master_log_name, &first_non_digit, 10); if (mi->master_log_name[0]!='\0' && *first_non_digit=='\0' && lines >= LINES_IN_MASTER_INFO_WITH_SSL) { // Seems to be new format if (init_strvar_from_file(mi->master_log_name, sizeof(mi->master_log_name), &mi->file, "")) goto errwithmsg; } else lines= 7; if (init_intvar_from_file(&master_log_pos, &mi->file, 4) || init_strvar_from_file(mi->host, sizeof(mi->host), &mi->file, master_host) || init_strvar_from_file(mi->user, sizeof(mi->user), &mi->file, master_user) || init_strvar_from_file(mi->password, SCRAMBLED_PASSWORD_CHAR_LENGTH+1, &mi->file, master_password) || init_intvar_from_file(&port, &mi->file, master_port) || init_intvar_from_file(&connect_retry, &mi->file, master_connect_retry)) goto errwithmsg; /* If file has ssl part use it even if we have server without SSL support. But these option will be ignored later when slave will try connect to master, so in this case warning is printed. */ if (lines >= LINES_IN_MASTER_INFO_WITH_SSL && (init_intvar_from_file(&ssl, &mi->file, master_ssl) || init_strvar_from_file(mi->ssl_ca, sizeof(mi->ssl_ca), &mi->file, master_ssl_ca) || init_strvar_from_file(mi->ssl_capath, sizeof(mi->ssl_capath), &mi->file, master_ssl_capath) || init_strvar_from_file(mi->ssl_cert, sizeof(mi->ssl_cert), &mi->file, master_ssl_cert) || init_strvar_from_file(mi->ssl_cipher, sizeof(mi->ssl_cipher), &mi->file, master_ssl_cipher) || init_strvar_from_file(mi->ssl_key, sizeof(mi->ssl_key), &mi->file, master_ssl_key))) goto errwithmsg; #ifndef HAVE_OPENSSL if (ssl) sql_print_error("SSL information in the master info file " "('%s') are ignored because this MySQL slave was compiled " "without SSL support.", fname); #endif /* HAVE_OPENSSL */ /* This has to be handled here as init_intvar_from_file can't handle my_off_t types */ mi->master_log_pos= (my_off_t) master_log_pos; mi->port= (uint) port; mi->connect_retry= (uint) connect_retry; mi->ssl= (my_bool) ssl; } DBUG_PRINT("master_info",("log_file_name: %s position: %ld", mi->master_log_name, (ulong) mi->master_log_pos)); mi->rli.mi = mi; if (init_relay_log_info(&mi->rli, slave_info_fname)) goto err; mi->inited = 1; // now change cache READ -> WRITE - must do this before flush_master_info reinit_io_cache(&mi->file, WRITE_CACHE,0L,0,1); if ((error=test(flush_master_info(mi, 1)))) sql_print_error("Failed to flush master info file"); pthread_mutex_unlock(&mi->data_lock); DBUG_RETURN(error); errwithmsg: sql_print_error("Error reading master configuration"); err: if (fd >= 0) { my_close(fd, MYF(0)); end_io_cache(&mi->file); } mi->fd= -1; pthread_mutex_unlock(&mi->data_lock); DBUG_RETURN(1); } int register_slave_on_master(MYSQL* mysql) { char buf[1024], *pos= buf; uint report_host_len, report_user_len=0, report_password_len=0; if (!report_host) return 0; report_host_len= strlen(report_host); if (report_user) report_user_len= strlen(report_user); if (report_password) report_password_len= strlen(report_password); /* 30 is a good safety margin */ if (report_host_len + report_user_len + report_password_len + 30 > sizeof(buf)) return 0; // safety int4store(pos, server_id); pos+= 4; pos= net_store_data(pos, report_host, report_host_len); pos= net_store_data(pos, report_user, report_user_len); pos= net_store_data(pos, report_password, report_password_len); int2store(pos, (uint16) report_port); pos+= 2; int4store(pos, rpl_recovery_rank); pos+= 4; /* The master will fill in master_id */ int4store(pos, 0); pos+= 4; if (simple_command(mysql, COM_REGISTER_SLAVE, (char*) buf, (uint) (pos- buf), 0)) { sql_print_error("Error on COM_REGISTER_SLAVE: %d '%s'", mysql_errno(mysql), mysql_error(mysql)); return 1; } return 0; } /* Builds a String from a HASH of TABLE_RULE_ENT. Cannot be used for any other hash, as it assumes that the hash entries are TABLE_RULE_ENT. SYNOPSIS table_rule_ent_hash_to_str() s pointer to the String to fill h pointer to the HASH to read RETURN VALUES none */ void table_rule_ent_hash_to_str(String* s, HASH* h) { s->length(0); for (uint i=0 ; i < h->records ; i++) { TABLE_RULE_ENT* e= (TABLE_RULE_ENT*) hash_element(h, i); if (s->length()) s->append(','); s->append(e->db,e->key_len); } } /* Mostly the same thing as above */ void table_rule_ent_dynamic_array_to_str(String* s, DYNAMIC_ARRAY* a) { s->length(0); for (uint i=0 ; i < a->elements ; i++) { TABLE_RULE_ENT* e; get_dynamic(a, (gptr)&e, i); if (s->length()) s->append(','); s->append(e->db,e->key_len); } } int show_master_info(THD* thd, MASTER_INFO* mi) { // TODO: fix this for multi-master List field_list; Protocol *protocol= thd->protocol; DBUG_ENTER("show_master_info"); field_list.push_back(new Item_empty_string("Slave_IO_State", 14)); field_list.push_back(new Item_empty_string("Master_Host", sizeof(mi->host))); field_list.push_back(new Item_empty_string("Master_User", sizeof(mi->user))); field_list.push_back(new Item_return_int("Master_Port", 7, MYSQL_TYPE_LONG)); field_list.push_back(new Item_return_int("Connect_Retry", 10, MYSQL_TYPE_LONG)); field_list.push_back(new Item_empty_string("Master_Log_File", FN_REFLEN)); field_list.push_back(new Item_return_int("Read_Master_Log_Pos", 10, MYSQL_TYPE_LONGLONG)); field_list.push_back(new Item_empty_string("Relay_Log_File", FN_REFLEN)); field_list.push_back(new Item_return_int("Relay_Log_Pos", 10, MYSQL_TYPE_LONGLONG)); field_list.push_back(new Item_empty_string("Relay_Master_Log_File", FN_REFLEN)); field_list.push_back(new Item_empty_string("Slave_IO_Running", 3)); field_list.push_back(new Item_empty_string("Slave_SQL_Running", 3)); field_list.push_back(new Item_empty_string("Replicate_Do_DB", 20)); field_list.push_back(new Item_empty_string("Replicate_Ignore_DB", 20)); field_list.push_back(new Item_empty_string("Replicate_Do_Table", 20)); field_list.push_back(new Item_empty_string("Replicate_Ignore_Table", 23)); field_list.push_back(new Item_empty_string("Replicate_Wild_Do_Table", 24)); field_list.push_back(new Item_empty_string("Replicate_Wild_Ignore_Table", 28)); field_list.push_back(new Item_return_int("Last_Errno", 4, MYSQL_TYPE_LONG)); field_list.push_back(new Item_empty_string("Last_Error", 20)); field_list.push_back(new Item_return_int("Skip_Counter", 10, MYSQL_TYPE_LONG)); field_list.push_back(new Item_return_int("Exec_Master_Log_Pos", 10, MYSQL_TYPE_LONGLONG)); field_list.push_back(new Item_return_int("Relay_Log_Space", 10, MYSQL_TYPE_LONGLONG)); field_list.push_back(new Item_empty_string("Until_Condition", 6)); field_list.push_back(new Item_empty_string("Until_Log_File", FN_REFLEN)); field_list.push_back(new Item_return_int("Until_Log_Pos", 10, MYSQL_TYPE_LONGLONG)); field_list.push_back(new Item_empty_string("Master_SSL_Allowed", 7)); field_list.push_back(new Item_empty_string("Master_SSL_CA_File", sizeof(mi->ssl_ca))); field_list.push_back(new Item_empty_string("Master_SSL_CA_Path", sizeof(mi->ssl_capath))); field_list.push_back(new Item_empty_string("Master_SSL_Cert", sizeof(mi->ssl_cert))); field_list.push_back(new Item_empty_string("Master_SSL_Cipher", sizeof(mi->ssl_cipher))); field_list.push_back(new Item_empty_string("Master_SSL_Key", sizeof(mi->ssl_key))); field_list.push_back(new Item_return_int("Seconds_Behind_Master", 10, MYSQL_TYPE_LONGLONG)); if (protocol->send_fields(&field_list, 1)) DBUG_RETURN(-1); if (mi->host[0]) { DBUG_PRINT("info",("host is set: '%s'", mi->host)); String *packet= &thd->packet; protocol->prepare_for_resend(); /* TODO: we read slave_running without run_lock, whereas these variables are updated under run_lock and not data_lock. In 5.0 we should lock run_lock on top of data_lock (with good order). */ pthread_mutex_lock(&mi->data_lock); pthread_mutex_lock(&mi->rli.data_lock); protocol->store(mi->io_thd ? mi->io_thd->proc_info : "", &my_charset_bin); protocol->store(mi->host, &my_charset_bin); protocol->store(mi->user, &my_charset_bin); protocol->store((uint32) mi->port); protocol->store((uint32) mi->connect_retry); protocol->store(mi->master_log_name, &my_charset_bin); protocol->store((ulonglong) mi->master_log_pos); protocol->store(mi->rli.group_relay_log_name + dirname_length(mi->rli.group_relay_log_name), &my_charset_bin); protocol->store((ulonglong) mi->rli.group_relay_log_pos); protocol->store(mi->rli.group_master_log_name, &my_charset_bin); protocol->store(mi->slave_running == MYSQL_SLAVE_RUN_CONNECT ? "Yes" : "No", &my_charset_bin); protocol->store(mi->rli.slave_running ? "Yes":"No", &my_charset_bin); protocol->store(&replicate_do_db); protocol->store(&replicate_ignore_db); /* We can't directly use some protocol->store for replicate_*_table, as Protocol doesn't know the TABLE_RULE_ENT struct. We first build Strings and then pass them to protocol->store. */ char buf[256]; String tmp(buf, sizeof(buf), &my_charset_bin); table_rule_ent_hash_to_str(&tmp, &replicate_do_table); protocol->store(&tmp); table_rule_ent_hash_to_str(&tmp, &replicate_ignore_table); protocol->store(&tmp); table_rule_ent_dynamic_array_to_str(&tmp, &replicate_wild_do_table); protocol->store(&tmp); table_rule_ent_dynamic_array_to_str(&tmp, &replicate_wild_ignore_table); protocol->store(&tmp); protocol->store((uint32) mi->rli.last_slave_errno); protocol->store(mi->rli.last_slave_error, &my_charset_bin); protocol->store((uint32) mi->rli.slave_skip_counter); protocol->store((ulonglong) mi->rli.group_master_log_pos); protocol->store((ulonglong) mi->rli.log_space_total); protocol->store( mi->rli.until_condition==RELAY_LOG_INFO::UNTIL_NONE ? "None": ( mi->rli.until_condition==RELAY_LOG_INFO::UNTIL_MASTER_POS? "Master": "Relay"), &my_charset_bin); protocol->store(mi->rli.until_log_name, &my_charset_bin); protocol->store((ulonglong) mi->rli.until_log_pos); #ifdef HAVE_OPENSSL protocol->store(mi->ssl? "Yes":"No", &my_charset_bin); #else protocol->store(mi->ssl? "Ignored":"No", &my_charset_bin); #endif protocol->store(mi->ssl_ca, &my_charset_bin); protocol->store(mi->ssl_capath, &my_charset_bin); protocol->store(mi->ssl_cert, &my_charset_bin); protocol->store(mi->ssl_cipher, &my_charset_bin); protocol->store(mi->ssl_key, &my_charset_bin); /* Seconds_Behind_Master: if SQL thread is running and I/O thread is connected, we can compute it otherwise show NULL (i.e. unknown). */ if ((mi->slave_running == MYSQL_SLAVE_RUN_CONNECT) && mi->rli.slave_running) { long tmp= (long)((time_t)time((time_t*) 0) - mi->rli.last_master_timestamp) - mi->clock_diff_with_master; /* Apparently on some systems tmp can be <0. Here are possible reasons related to MySQL: - the master is itself a slave of another master whose time is ahead. - somebody used an explicit SET TIMESTAMP on the master. Possible reason related to granularity-to-second of time functions (nothing to do with MySQL), which can explain a value of -1: assume the master's and slave's time are perfectly synchronized, and that at slave's connection time, when the master's timestamp is read, it is at the very end of second 1, and (a very short time later) when the slave's timestamp is read it is at the very beginning of second 2. Then the recorded value for master is 1 and the recorded value for slave is 2. At SHOW SLAVE STATUS time, assume that the difference between timestamp of slave and rli->last_master_timestamp is 0 (i.e. they are in the same second), then we get 0-(2-1)=-1 as a result. This confuses users, so we don't go below 0: hence the max(). last_master_timestamp == 0 (an "impossible" timestamp 1970) is a special marker to say "consider we have caught up". */ protocol->store((longlong)(mi->rli.last_master_timestamp ? max(0, tmp) : 0)); } else protocol->store_null(); pthread_mutex_unlock(&mi->rli.data_lock); pthread_mutex_unlock(&mi->data_lock); if (my_net_write(&thd->net, (char*)thd->packet.ptr(), packet->length())) DBUG_RETURN(-1); } send_eof(thd); DBUG_RETURN(0); } bool flush_master_info(MASTER_INFO* mi, bool flush_relay_log_cache) { IO_CACHE* file = &mi->file; char lbuf[22]; DBUG_ENTER("flush_master_info"); DBUG_PRINT("enter",("master_pos: %ld", (long) mi->master_log_pos)); /* Flush the relay log to disk. If we don't do it, then the relay log while have some part (its last kilobytes) in memory only, so if the slave server dies now, with, say, from master's position 100 to 150 in memory only (not on disk), and with position 150 in master.info, then when the slave restarts, the I/O thread will fetch binlogs from 150, so in the relay log we will have "[0, 100] U [150, infinity[" and nobody will notice it, so the SQL thread will jump from 100 to 150, and replication will silently break. When we come to this place in code, relay log may or not be initialized; the caller is responsible for setting 'flush_relay_log_cache' accordingly. */ if (flush_relay_log_cache) flush_io_cache(mi->rli.relay_log.get_log_file()); /* We flushed the relay log BEFORE the master.info file, because if we crash now, we will get a duplicate event in the relay log at restart. If we flushed in the other order, we would get a hole in the relay log. And duplicate is better than hole (with a duplicate, in later versions we can add detection and scrap one event; with a hole there's nothing we can do). */ /* In certain cases this code may create master.info files that seems corrupted, because of extra lines filled with garbage in the end file (this happens if new contents take less space than previous contents of file). But because of number of lines in the first line of file we don't care about this garbage. */ my_b_seek(file, 0L); my_b_printf(file, "%u\n%s\n%s\n%s\n%s\n%s\n%d\n%d\n%d\n%s\n%s\n%s\n%s\n%s\n", LINES_IN_MASTER_INFO_WITH_SSL, mi->master_log_name, llstr(mi->master_log_pos, lbuf), mi->host, mi->user, mi->password, mi->port, mi->connect_retry, (int)(mi->ssl), mi->ssl_ca, mi->ssl_capath, mi->ssl_cert, mi->ssl_cipher, mi->ssl_key); flush_io_cache(file); DBUG_RETURN(0); } st_relay_log_info::st_relay_log_info() :info_fd(-1), cur_log_fd(-1), save_temporary_tables(0), cur_log_old_open_count(0), group_master_log_pos(0), log_space_total(0), ignore_log_space_limit(0), last_master_timestamp(0), slave_skip_counter(0), abort_pos_wait(0), slave_run_id(0), sql_thd(0), last_slave_errno(0), inited(0), abort_slave(0), slave_running(0), until_condition(UNTIL_NONE), until_log_pos(0), retried_trans(0) { group_relay_log_name[0]= event_relay_log_name[0]= group_master_log_name[0]= 0; last_slave_error[0]= until_log_name[0]= ign_master_log_name_end[0]= 0; bzero((char*) &info_file, sizeof(info_file)); bzero((char*) &cache_buf, sizeof(cache_buf)); pthread_mutex_init(&run_lock, MY_MUTEX_INIT_FAST); pthread_mutex_init(&data_lock, MY_MUTEX_INIT_FAST); pthread_mutex_init(&log_space_lock, MY_MUTEX_INIT_FAST); pthread_cond_init(&data_cond, NULL); pthread_cond_init(&start_cond, NULL); pthread_cond_init(&stop_cond, NULL); pthread_cond_init(&log_space_cond, NULL); relay_log.init_pthread_objects(); } st_relay_log_info::~st_relay_log_info() { pthread_mutex_destroy(&run_lock); pthread_mutex_destroy(&data_lock); pthread_mutex_destroy(&log_space_lock); pthread_cond_destroy(&data_cond); pthread_cond_destroy(&start_cond); pthread_cond_destroy(&stop_cond); pthread_cond_destroy(&log_space_cond); } /* Waits until the SQL thread reaches (has executed up to) the log/position or timed out. SYNOPSIS wait_for_pos() thd client thread that sent SELECT MASTER_POS_WAIT log_name log name to wait for log_pos position to wait for timeout timeout in seconds before giving up waiting NOTES timeout is longlong whereas it should be ulong ; but this is to catch if the user submitted a negative timeout. RETURN VALUES -2 improper arguments (log_pos<0) or slave not running, or master info changed during the function's execution, or client thread killed. -2 is translated to NULL by caller -1 timed out >=0 number of log events the function had to wait before reaching the desired log/position */ int st_relay_log_info::wait_for_pos(THD* thd, String* log_name, longlong log_pos, longlong timeout) { if (!inited) return -1; int event_count = 0; ulong init_abort_pos_wait; int error=0; struct timespec abstime; // for timeout checking set_timespec(abstime,timeout); DBUG_ENTER("wait_for_pos"); DBUG_PRINT("enter",("group_master_log_name: '%s' pos: %lu timeout: %ld", group_master_log_name, (ulong) group_master_log_pos, (long) timeout)); pthread_mutex_lock(&data_lock); const char *msg= thd->enter_cond(&data_cond, &data_lock, "Waiting for the slave SQL thread to " "advance position"); /* This function will abort when it notices that some CHANGE MASTER or RESET MASTER has changed the master info. To catch this, these commands modify abort_pos_wait ; We just monitor abort_pos_wait and see if it has changed. Why do we have this mechanism instead of simply monitoring slave_running in the loop (we do this too), as CHANGE MASTER/RESET SLAVE require that the SQL thread be stopped? This is becasue if someones does: STOP SLAVE;CHANGE MASTER/RESET SLAVE; START SLAVE; the change may happen very quickly and we may not notice that slave_running briefly switches between 1/0/1. */ init_abort_pos_wait= abort_pos_wait; /* We'll need to handle all possible log names comparisons (e.g. 999 vs 1000). We use ulong for string->number conversion ; this is no stronger limitation than in find_uniq_filename in sql/log.cc */ ulong log_name_extension; char log_name_tmp[FN_REFLEN]; //make a char[] from String strmake(log_name_tmp, log_name->ptr(), min(log_name->length(), FN_REFLEN-1)); char *p= fn_ext(log_name_tmp); char *p_end; if (!*p || log_pos<0) { error= -2; //means improper arguments goto err; } // Convert 0-3 to 4 log_pos= max(log_pos, BIN_LOG_HEADER_SIZE); /* p points to '.' */ log_name_extension= strtoul(++p, &p_end, 10); /* p_end points to the first invalid character. If it equals to p, no digits were found, error. If it contains '\0' it means conversion went ok. */ if (p_end==p || *p_end) { error= -2; goto err; } /* The "compare and wait" main loop */ while (!thd->killed && init_abort_pos_wait == abort_pos_wait && slave_running) { bool pos_reached; int cmp_result= 0; /* group_master_log_name can be "", if we are just after a fresh replication start or after a CHANGE MASTER TO MASTER_HOST/PORT (before we have executed one Rotate event from the master) or (rare) if the user is doing a weird slave setup (see next paragraph). If group_master_log_name is "", we assume we don't have enough info to do the comparison yet, so we just wait until more data. In this case master_log_pos is always 0 except if somebody (wrongly) sets this slave to be a slave of itself without using --replicate-same-server-id (an unsupported configuration which does nothing), then group_master_log_pos will grow and group_master_log_name will stay "". */ if (*group_master_log_name) { char *basename= (group_master_log_name + dirname_length(group_master_log_name)); /* First compare the parts before the extension. Find the dot in the master's log basename, and protect against user's input error : if the names do not match up to '.' included, return error */ char *q= (char*)(fn_ext(basename)+1); if (strncmp(basename, log_name_tmp, (int)(q-basename))) { error= -2; break; } // Now compare extensions. char *q_end; ulong group_master_log_name_extension= strtoul(q, &q_end, 10); if (group_master_log_name_extension < log_name_extension) cmp_result= -1 ; else cmp_result= (group_master_log_name_extension > log_name_extension) ? 1 : 0 ; pos_reached= ((!cmp_result && group_master_log_pos >= (ulonglong)log_pos) || cmp_result > 0); if (pos_reached || thd->killed) break; } //wait for master update, with optional timeout. DBUG_PRINT("info",("Waiting for master update")); /* We are going to pthread_cond_(timed)wait(); if the SQL thread stops it will wake us up. */ if (timeout > 0) { /* Note that pthread_cond_timedwait checks for the timeout before for the condition ; i.e. it returns ETIMEDOUT if the system time equals or exceeds the time specified by abstime before the condition variable is signaled or broadcast, _or_ if the absolute time specified by abstime has already passed at the time of the call. For that reason, pthread_cond_timedwait will do the "timeoutting" job even if its condition is always immediately signaled (case of a loaded master). */ error=pthread_cond_timedwait(&data_cond, &data_lock, &abstime); } else pthread_cond_wait(&data_cond, &data_lock); DBUG_PRINT("info",("Got signal of master update or timed out")); if (error == ETIMEDOUT || error == ETIME) { error= -1; break; } error=0; event_count++; DBUG_PRINT("info",("Testing if killed or SQL thread not running")); } err: thd->exit_cond(msg); DBUG_PRINT("exit",("killed: %d abort: %d slave_running: %d \ improper_arguments: %d timed_out: %d", (int) thd->killed, (int) (init_abort_pos_wait != abort_pos_wait), (int) slave_running, (int) (error == -2), (int) (error == -1))); if (thd->killed || init_abort_pos_wait != abort_pos_wait || !slave_running) { error= -2; } DBUG_RETURN( error ? error : event_count ); } /* init_slave_thread() */ static int init_slave_thread(THD* thd, SLAVE_THD_TYPE thd_type) { DBUG_ENTER("init_slave_thread"); thd->system_thread = (thd_type == SLAVE_THD_SQL) ? SYSTEM_THREAD_SLAVE_SQL : SYSTEM_THREAD_SLAVE_IO; thd->host_or_ip= ""; my_net_init(&thd->net, 0); thd->net.read_timeout = slave_net_timeout; thd->master_access= ~(ulong)0; thd->priv_user = 0; thd->slave_thread = 1; /* It's nonsense to constrain the slave threads with max_join_size; if a query succeeded on master, we HAVE to execute it. So set OPTION_BIG_SELECTS. Setting max_join_size to HA_POS_ERROR is not enough (and it's not needed if we have OPTION_BIG_SELECTS) because an INSERT SELECT examining more than 4 billion rows would still fail (yes, because when max_join_size is 4G, OPTION_BIG_SELECTS is automatically set, but only for client threads. */ thd->options = ((opt_log_slave_updates) ? OPTION_BIN_LOG:0) | OPTION_AUTO_IS_NULL | OPTION_BIG_SELECTS; thd->client_capabilities = CLIENT_LOCAL_FILES; thd->real_id=pthread_self(); pthread_mutex_lock(&LOCK_thread_count); thd->thread_id = thread_id++; pthread_mutex_unlock(&LOCK_thread_count); if (init_thr_lock() || thd->store_globals()) { thd->cleanup(); delete thd; DBUG_RETURN(-1); } #if !defined(__WIN__) && !defined(OS2) && !defined(__NETWARE__) sigset_t set; VOID(sigemptyset(&set)); // Get mask in use VOID(pthread_sigmask(SIG_UNBLOCK,&set,&thd->block_signals)); #endif if (thd_type == SLAVE_THD_SQL) thd->proc_info= "Waiting for the next event in relay log"; else thd->proc_info= "Waiting for master update"; thd->version=refresh_version; thd->set_time(); DBUG_RETURN(0); } static int safe_sleep(THD* thd, int sec, CHECK_KILLED_FUNC thread_killed, void* thread_killed_arg) { int nap_time; thr_alarm_t alarmed; thr_alarm_init(&alarmed); time_t start_time= time((time_t*) 0); time_t end_time= start_time+sec; while ((nap_time= (int) (end_time - start_time)) > 0) { ALARM alarm_buff; /* The only reason we are asking for alarm is so that we will be woken up in case of murder, so if we do not get killed, set the alarm so it goes off after we wake up naturally */ thr_alarm(&alarmed, 2 * nap_time, &alarm_buff); sleep(nap_time); thr_end_alarm(&alarmed); if ((*thread_killed)(thd,thread_killed_arg)) return 1; start_time=time((time_t*) 0); } return 0; } static int request_dump(MYSQL* mysql, MASTER_INFO* mi, bool *suppress_warnings) { char buf[FN_REFLEN + 10]; int len; int binlog_flags = 0; // for now char* logname = mi->master_log_name; DBUG_ENTER("request_dump"); // TODO if big log files: Change next to int8store() int4store(buf, (ulong) mi->master_log_pos); int2store(buf + 4, binlog_flags); int4store(buf + 6, server_id); len = (uint) strlen(logname); memcpy(buf + 10, logname,len); if (simple_command(mysql, COM_BINLOG_DUMP, buf, len + 10, 1)) { /* Something went wrong, so we will just reconnect and retry later in the future, we should do a better error analysis, but for now we just fill up the error log :-) */ if (mysql_errno(mysql) == ER_NET_READ_INTERRUPTED) *suppress_warnings= 1; // Suppress reconnect warning else sql_print_error("Error on COM_BINLOG_DUMP: %d %s, will retry in %d secs", mysql_errno(mysql), mysql_error(mysql), master_connect_retry); DBUG_RETURN(1); } DBUG_RETURN(0); } static int request_table_dump(MYSQL* mysql, const char* db, const char* table) { char buf[1024]; char * p = buf; uint table_len = (uint) strlen(table); uint db_len = (uint) strlen(db); if (table_len + db_len > sizeof(buf) - 2) { sql_print_error("request_table_dump: Buffer overrun"); return 1; } *p++ = db_len; memcpy(p, db, db_len); p += db_len; *p++ = table_len; memcpy(p, table, table_len); if (simple_command(mysql, COM_TABLE_DUMP, buf, p - buf + table_len, 1)) { sql_print_error("request_table_dump: Error sending the table dump \ command"); return 1; } return 0; } /* Read one event from the master SYNOPSIS read_event() mysql MySQL connection mi Master connection information suppress_warnings TRUE when a normal net read timeout has caused us to try a reconnect. We do not want to print anything to the error log in this case because this a anormal event in an idle server. RETURN VALUES 'packet_error' Error number Length of packet */ static ulong read_event(MYSQL* mysql, MASTER_INFO *mi, bool* suppress_warnings) { ulong len; *suppress_warnings= 0; /* my_real_read() will time us out We check if we were told to die, and if not, try reading again TODO: Move 'events_till_disconnect' to the MASTER_INFO structure */ #ifndef DBUG_OFF if (disconnect_slave_event_count && !(events_till_disconnect--)) return packet_error; #endif len = net_safe_read(mysql); if (len == packet_error || (long) len < 1) { if (mysql_errno(mysql) == ER_NET_READ_INTERRUPTED) { /* We are trying a normal reconnect after a read timeout; we suppress prints to .err file as long as the reconnect happens without problems */ *suppress_warnings= TRUE; } else sql_print_error("Error reading packet from server: %s (\ server_errno=%d)", mysql_error(mysql), mysql_errno(mysql)); return packet_error; } /* Check if eof packet */ if (len < 8 && mysql->net.read_pos[0] == 254) { sql_print_error("Slave: received end packet from server, apparent\ master shutdown: %s", mysql_error(mysql)); return packet_error; } DBUG_PRINT("info",( "len=%u, net->read_pos[4] = %d\n", len, mysql->net.read_pos[4])); return len - 1; } int check_expected_error(THD* thd, RELAY_LOG_INFO* rli, int expected_error) { switch (expected_error) { case ER_NET_READ_ERROR: case ER_NET_ERROR_ON_WRITE: case ER_SERVER_SHUTDOWN: case ER_NEW_ABORTING_CONNECTION: return 1; default: return 0; } } /* Check if condition stated in UNTIL clause of START SLAVE is reached. SYNOPSYS st_relay_log_info::is_until_satisfied() DESCRIPTION Checks if UNTIL condition is reached. Uses caching result of last comparison of current log file name and target log file name. So cached value should be invalidated if current log file name changes (see st_relay_log_info::notify_... functions). This caching is needed to avoid of expensive string comparisons and strtol() conversions needed for log names comparison. We don't need to compare them each time this function is called, we only need to do this when current log name changes. If we have UNTIL_MASTER_POS condition we need to do this only after Rotate_log_event::exec_event() (which is rare, so caching gives real benifit), and if we have UNTIL_RELAY_POS condition then we should invalidate cached comarison value after inc_group_relay_log_pos() which called for each group of events (so we have some benefit if we have something like queries that use autoincrement or if we have transactions). Should be called ONLY if until_condition != UNTIL_NONE ! RETURN VALUE true - condition met or error happened (condition seems to have bad log file name) false - condition not met */ bool st_relay_log_info::is_until_satisfied() { const char *log_name; ulonglong log_pos; DBUG_ASSERT(until_condition != UNTIL_NONE); if (until_condition == UNTIL_MASTER_POS) { log_name= group_master_log_name; log_pos= group_master_log_pos; } else { /* until_condition == UNTIL_RELAY_POS */ log_name= group_relay_log_name; log_pos= group_relay_log_pos; } if (until_log_names_cmp_result == UNTIL_LOG_NAMES_CMP_UNKNOWN) { /* We have no cached comaprison results so we should compare log names and cache result */ DBUG_ASSERT(*log_name || log_pos == 0); if (*log_name) { const char *basename= log_name + dirname_length(log_name); const char *q= (const char*)(fn_ext(basename)+1); if (strncmp(basename, until_log_name, (int)(q-basename)) == 0) { /* Now compare extensions. */ char *q_end; ulong log_name_extension= strtoul(q, &q_end, 10); if (log_name_extension < until_log_name_extension) until_log_names_cmp_result= UNTIL_LOG_NAMES_CMP_LESS; else until_log_names_cmp_result= (log_name_extension > until_log_name_extension) ? UNTIL_LOG_NAMES_CMP_GREATER : UNTIL_LOG_NAMES_CMP_EQUAL ; } else { /* Probably error so we aborting */ sql_print_error("Slave SQL thread is stopped because UNTIL " "condition is bad."); return TRUE; } } else return until_log_pos == 0; } return ((until_log_names_cmp_result == UNTIL_LOG_NAMES_CMP_EQUAL && log_pos >= until_log_pos) || until_log_names_cmp_result == UNTIL_LOG_NAMES_CMP_GREATER); } static int exec_relay_log_event(THD* thd, RELAY_LOG_INFO* rli) { /* We acquire this mutex since we need it for all operations except event execution. But we will release it in places where we will wait for something for example inside of next_event(). */ pthread_mutex_lock(&rli->data_lock); /* This tests if the position of the end of the last previous executed event hits the UNTIL barrier. We would prefer to test if the position of the start (or possibly) end of the to-be-read event hits the UNTIL barrier, this is different if there was an event ignored by the I/O thread just before (BUG#13861 to be fixed). */ if (rli->until_condition!=RELAY_LOG_INFO::UNTIL_NONE && rli->is_until_satisfied()) { char buf[22]; sql_print_error("Slave SQL thread stopped because it reached its" " UNTIL position %s", llstr(rli->until_pos(), buf)); /* Setting abort_slave flag because we do not want additional message about error in query execution to be printed. */ rli->abort_slave= 1; pthread_mutex_unlock(&rli->data_lock); return 1; } Log_event * ev = next_event(rli); DBUG_ASSERT(rli->sql_thd==thd); if (sql_slave_killed(thd,rli)) { pthread_mutex_unlock(&rli->data_lock); delete ev; return 1; } if (ev) { int type_code = ev->get_type_code(); int exec_res; /* Skip queries originating from this server or number of queries specified by the user in slave_skip_counter We can't however skip event's that has something to do with the log files themselves. */ if ((ev->server_id == (uint32) ::server_id && !replicate_same_server_id) || (rli->slave_skip_counter && type_code != ROTATE_EVENT)) { rli->inc_group_relay_log_pos(ev->get_event_len(), type_code != STOP_EVENT ? ev->log_pos : LL(0), 1/* skip lock*/); flush_relay_log_info(rli); /* Protect against common user error of setting the counter to 1 instead of 2 while recovering from an failed auto-increment insert */ if (rli->slave_skip_counter && !((type_code == INTVAR_EVENT || type_code == STOP_EVENT) && rli->slave_skip_counter == 1)) --rli->slave_skip_counter; pthread_mutex_unlock(&rli->data_lock); delete ev; return 0; // avoid infinite update loops } pthread_mutex_unlock(&rli->data_lock); thd->server_id = ev->server_id; // use the original server id for logging thd->set_time(); // time the query thd->lex->current_select= 0; if (!ev->when) ev->when = time(NULL); ev->thd = thd; exec_res = ev->exec_event(rli); DBUG_ASSERT(rli->sql_thd==thd); delete ev; if (slave_trans_retries) { if (exec_res && (thd->net.last_errno == ER_LOCK_DEADLOCK || thd->net.last_errno == ER_LOCK_WAIT_TIMEOUT) && !thd->is_fatal_error) { const char *errmsg; /* We were in a transaction which has been rolled back because of a deadlock (currently, InnoDB deadlock detected by InnoDB) or lock wait timeout (innodb_lock_wait_timeout exceeded); let's seek back to BEGIN log event and retry it all again. We have to not only seek but also a) init_master_info(), to seek back to hot relay log's start for later (for when we will come back to this hot log after re-processing the possibly existing old logs where BEGIN is: check_binlog_magic() will then need the cache to be at position 0 (see comments at beginning of init_master_info()). b) init_relay_log_pos(), because the BEGIN may be an older relay log. */ if (rli->trans_retries < slave_trans_retries) { if (init_master_info(rli->mi, 0, 0, 0, SLAVE_SQL)) sql_print_error("Failed to initialize the master info structure"); else if (init_relay_log_pos(rli, rli->group_relay_log_name, rli->group_relay_log_pos, 1, &errmsg)) sql_print_error("Error initializing relay log position: %s", errmsg); else { exec_res= 0; /* chance for concurrent connection to get more locks */ safe_sleep(thd, min(rli->trans_retries, MAX_SLAVE_RETRY_PAUSE), (CHECK_KILLED_FUNC)sql_slave_killed, (void*)rli); pthread_mutex_lock(&rli->data_lock); // because of SHOW STATUS rli->trans_retries++; rli->retried_trans++; pthread_mutex_unlock(&rli->data_lock); DBUG_PRINT("info", ("Slave retries transaction " "rli->trans_retries: %lu", rli->trans_retries)); } } else sql_print_error("Slave SQL thread retried transaction %lu time(s) " "in vain, giving up. Consider raising the value of " "the slave_transaction_retries variable.", slave_trans_retries); } if (!((thd->options & OPTION_BEGIN) && opt_using_transactions)) rli->trans_retries= 0; // restart from fresh } return exec_res; } else { pthread_mutex_unlock(&rli->data_lock); slave_print_error(rli, 0, "\ Could not parse relay log event entry. The possible reasons are: the master's \ binary log is corrupted (you can check this by running 'mysqlbinlog' on the \ binary log), the slave's relay log is corrupted (you can check this by running \ 'mysqlbinlog' on the relay log), a network problem, or a bug in the master's \ or slave's MySQL code. If you want to check the master's binary log or slave's \ relay log, you will be able to know their names by issuing 'SHOW SLAVE STATUS' \ on this slave.\ "); return 1; } } /* Slave I/O Thread entry point */ extern "C" pthread_handler_decl(handle_slave_io,arg) { THD *thd; // needs to be first for thread_stack MYSQL *mysql; MASTER_INFO *mi = (MASTER_INFO*)arg; RELAY_LOG_INFO *rli= &mi->rli; char llbuff[22]; uint retry_count; // needs to call my_thread_init(), otherwise we get a coredump in DBUG_ stuff my_thread_init(); DBUG_ENTER("handle_slave_io"); #ifndef DBUG_OFF slave_begin: #endif DBUG_ASSERT(mi->inited); mysql= NULL ; retry_count= 0; pthread_mutex_lock(&mi->run_lock); /* Inform waiting threads that slave has started */ mi->slave_run_id++; #ifndef DBUG_OFF mi->events_till_abort = abort_slave_event_count; #endif thd= new THD; // note that contructor of THD uses DBUG_ ! THD_CHECK_SENTRY(thd); pthread_detach_this_thread(); if (init_slave_thread(thd, SLAVE_THD_IO)) { pthread_cond_broadcast(&mi->start_cond); pthread_mutex_unlock(&mi->run_lock); sql_print_error("Failed during slave I/O thread initialization"); goto err; } mi->io_thd = thd; thd->thread_stack = (char*)&thd; // remember where our stack is pthread_mutex_lock(&LOCK_thread_count); threads.append(thd); pthread_mutex_unlock(&LOCK_thread_count); mi->slave_running = 1; mi->abort_slave = 0; pthread_mutex_unlock(&mi->run_lock); pthread_cond_broadcast(&mi->start_cond); DBUG_PRINT("master_info",("log_file_name: '%s' position: %s", mi->master_log_name, llstr(mi->master_log_pos,llbuff))); if (!(mi->mysql = mysql = mysql_init(NULL))) { sql_print_error("Slave I/O thread: error in mysql_init()"); goto err; } thd->proc_info = "Connecting to master"; // we can get killed during safe_connect if (!safe_connect(thd, mysql, mi)) sql_print_information("Slave I/O thread: connected to master '%s@%s:%d',\ replication started in log '%s' at position %s", mi->user, mi->host, mi->port, IO_RPL_LOG_NAME, llstr(mi->master_log_pos,llbuff)); else { sql_print_error("Slave I/O thread killed while connecting to master"); goto err; } connected: // TODO: the assignment below should be under mutex (5.0) mi->slave_running= MYSQL_SLAVE_RUN_CONNECT; thd->slave_net = &mysql->net; thd->proc_info = "Checking master version"; if (get_master_version_and_clock(mysql, mi)) goto err; if (!mi->old_format) { /* Register ourselves with the master. If fails, this is not fatal - we just print the error message and go on with life. */ thd->proc_info = "Registering slave on master"; if (register_slave_on_master(mysql) || update_slave_list(mysql, mi)) goto err; } DBUG_PRINT("info",("Starting reading binary log from master")); while (!io_slave_killed(thd,mi)) { bool suppress_warnings= 0; thd->proc_info = "Requesting binlog dump"; if (request_dump(mysql, mi, &suppress_warnings)) { sql_print_error("Failed on request_dump()"); if (io_slave_killed(thd,mi)) { sql_print_error("Slave I/O thread killed while requesting master \ dump"); goto err; } mi->slave_running= MYSQL_SLAVE_RUN_NOT_CONNECT; thd->proc_info= "Waiting to reconnect after a failed binlog dump request"; #ifdef SIGNAL_WITH_VIO_CLOSE thd->clear_active_vio(); #endif end_server(mysql); /* First time retry immediately, assuming that we can recover right away - if first time fails, sleep between re-tries hopefuly the admin can fix the problem sometime */ if (retry_count++) { if (retry_count > master_retry_count) goto err; // Don't retry forever safe_sleep(thd,mi->connect_retry,(CHECK_KILLED_FUNC)io_slave_killed, (void*)mi); } if (io_slave_killed(thd,mi)) { sql_print_error("Slave I/O thread killed while retrying master \ dump"); goto err; } thd->proc_info = "Reconnecting after a failed binlog dump request"; if (!suppress_warnings) sql_print_error("Slave I/O thread: failed dump request, \ reconnecting to try again, log '%s' at postion %s", IO_RPL_LOG_NAME, llstr(mi->master_log_pos,llbuff)); if (safe_reconnect(thd, mysql, mi, suppress_warnings) || io_slave_killed(thd,mi)) { sql_print_error("Slave I/O thread killed during or \ after reconnect"); goto err; } goto connected; } while (!io_slave_killed(thd,mi)) { bool suppress_warnings= 0; /* We say "waiting" because read_event() will wait if there's nothing to read. But if there's something to read, it will not wait. The important thing is to not confuse users by saying "reading" whereas we're in fact receiving nothing. */ thd->proc_info = "Waiting for master to send event"; ulong event_len = read_event(mysql, mi, &suppress_warnings); if (io_slave_killed(thd,mi)) { if (global_system_variables.log_warnings) sql_print_error("Slave I/O thread killed while reading event"); goto err; } if (event_len == packet_error) { uint mysql_error_number= mysql_errno(mysql); if (mysql_error_number == ER_NET_PACKET_TOO_LARGE) { sql_print_error("\ Log entry on master is longer than max_allowed_packet (%ld) on \ slave. If the entry is correct, restart the server with a higher value of \ max_allowed_packet", thd->variables.max_allowed_packet); goto err; } if (mysql_error_number == ER_MASTER_FATAL_ERROR_READING_BINLOG) { sql_print_error(ER(mysql_error_number), mysql_error_number, mysql_error(mysql)); goto err; } mi->slave_running= MYSQL_SLAVE_RUN_NOT_CONNECT; thd->proc_info = "Waiting to reconnect after a failed master event read"; #ifdef SIGNAL_WITH_VIO_CLOSE thd->clear_active_vio(); #endif end_server(mysql); if (retry_count++) { if (retry_count > master_retry_count) goto err; // Don't retry forever safe_sleep(thd,mi->connect_retry,(CHECK_KILLED_FUNC)io_slave_killed, (void*) mi); } if (io_slave_killed(thd,mi)) { if (global_system_variables.log_warnings) sql_print_error("Slave I/O thread killed while waiting to \ reconnect after a failed read"); goto err; } thd->proc_info = "Reconnecting after a failed master event read"; if (!suppress_warnings) sql_print_error("Slave I/O thread: Failed reading log event, \ reconnecting to retry, log '%s' position %s", IO_RPL_LOG_NAME, llstr(mi->master_log_pos, llbuff)); if (safe_reconnect(thd, mysql, mi, suppress_warnings) || io_slave_killed(thd,mi)) { if (global_system_variables.log_warnings) sql_print_error("Slave I/O thread killed during or after a \ reconnect done to recover from failed read"); goto err; } goto connected; } // if (event_len == packet_error) retry_count=0; // ok event, reset retry counter thd->proc_info = "Queueing master event to the relay log"; if (queue_event(mi,(const char*)mysql->net.read_pos + 1, event_len)) { sql_print_error("Slave I/O thread could not queue event from master"); goto err; } flush_master_info(mi, 1); /* sure that we can flush the relay log */ /* See if the relay logs take too much space. We don't lock mi->rli.log_space_lock here; this dirty read saves time and does not introduce any problem: - if mi->rli.ignore_log_space_limit is 1 but becomes 0 just after (so the clean value is 0), then we are reading only one more event as we should, and we'll block only at the next event. No big deal. - if mi->rli.ignore_log_space_limit is 0 but becomes 1 just after (so the clean value is 1), then we are going into wait_for_relay_log_space() for no reason, but this function will do a clean read, notice the clean value and exit immediately. */ #ifndef DBUG_OFF { char llbuf1[22], llbuf2[22]; DBUG_PRINT("info", ("log_space_limit=%s log_space_total=%s \ ignore_log_space_limit=%d", llstr(rli->log_space_limit,llbuf1), llstr(rli->log_space_total,llbuf2), (int) rli->ignore_log_space_limit)); } #endif if (rli->log_space_limit && rli->log_space_limit < rli->log_space_total && !rli->ignore_log_space_limit) if (wait_for_relay_log_space(rli)) { sql_print_error("Slave I/O thread aborted while waiting for relay \ log space"); goto err; } // TODO: check debugging abort code #ifndef DBUG_OFF if (abort_slave_event_count && !--events_till_abort) { sql_print_error("Slave I/O thread: debugging abort"); goto err; } #endif } } // error = 0; err: // print the current replication position sql_print_error("Slave I/O thread exiting, read up to log '%s', position %s", IO_RPL_LOG_NAME, llstr(mi->master_log_pos,llbuff)); VOID(pthread_mutex_lock(&LOCK_thread_count)); thd->query = thd->db = 0; // extra safety thd->query_length= thd->db_length= 0; VOID(pthread_mutex_unlock(&LOCK_thread_count)); if (mysql) { mysql_close(mysql); mi->mysql=0; } write_ignored_events_info_to_relay_log(thd, mi); thd->proc_info = "Waiting for slave mutex on exit"; pthread_mutex_lock(&mi->run_lock); mi->slave_running = 0; mi->io_thd = 0; // TODO: make rpl_status part of MASTER_INFO change_rpl_status(RPL_ACTIVE_SLAVE,RPL_IDLE_SLAVE); mi->abort_slave = 0; // TODO: check if this is needed DBUG_ASSERT(thd->net.buff != 0); net_end(&thd->net); // destructor will not free it, because net.vio is 0 close_thread_tables(thd, 0); pthread_mutex_lock(&LOCK_thread_count); THD_CHECK_SENTRY(thd); delete thd; pthread_mutex_unlock(&LOCK_thread_count); pthread_cond_broadcast(&mi->stop_cond); // tell the world we are done pthread_mutex_unlock(&mi->run_lock); #ifndef DBUG_OFF if (abort_slave_event_count && !events_till_abort) goto slave_begin; #endif my_thread_end(); pthread_exit(0); DBUG_RETURN(0); // Can't return anything here } /* Slave SQL Thread entry point */ extern "C" pthread_handler_decl(handle_slave_sql,arg) { THD *thd; /* needs to be first for thread_stack */ char llbuff[22],llbuff1[22]; RELAY_LOG_INFO* rli = &((MASTER_INFO*)arg)->rli; const char *errmsg; // needs to call my_thread_init(), otherwise we get a coredump in DBUG_ stuff my_thread_init(); DBUG_ENTER("handle_slave_sql"); #ifndef DBUG_OFF slave_begin: #endif DBUG_ASSERT(rli->inited); pthread_mutex_lock(&rli->run_lock); DBUG_ASSERT(!rli->slave_running); errmsg= 0; #ifndef DBUG_OFF rli->events_till_abort = abort_slave_event_count; #endif thd = new THD; // note that contructor of THD uses DBUG_ ! thd->thread_stack = (char*)&thd; // remember where our stack is /* Inform waiting threads that slave has started */ rli->slave_run_id++; pthread_detach_this_thread(); if (init_slave_thread(thd, SLAVE_THD_SQL)) { /* TODO: this is currently broken - slave start and change master will be stuck if we fail here */ pthread_cond_broadcast(&rli->start_cond); pthread_mutex_unlock(&rli->run_lock); sql_print_error("Failed during slave thread initialization"); goto err; } thd->init_for_queries(); rli->sql_thd= thd; thd->temporary_tables = rli->save_temporary_tables; // restore temp tables pthread_mutex_lock(&LOCK_thread_count); threads.append(thd); pthread_mutex_unlock(&LOCK_thread_count); /* We are going to set slave_running to 1. Assuming slave I/O thread is alive and connected, this is going to make Seconds_Behind_Master be 0 i.e. "caught up". Even if we're just at start of thread. Well it's ok, at the moment we start we can think we are caught up, and the next second we start receiving data so we realize we are not caught up and Seconds_Behind_Master grows. No big deal. */ rli->slave_running = 1; rli->abort_slave = 0; pthread_mutex_unlock(&rli->run_lock); pthread_cond_broadcast(&rli->start_cond); /* Reset errors for a clean start (otherwise, if the master is idle, the SQL thread may execute no Query_log_event, so the error will remain even though there's no problem anymore). Do not reset the master timestamp (imagine the slave has caught everything, the STOP SLAVE and START SLAVE: as we are not sure that we are going to receive a query, we want to remember the last master timestamp (to say how many seconds behind we are now. But the master timestamp is reset by RESET SLAVE & CHANGE MASTER. */ clear_slave_error(rli); //tell the I/O thread to take relay_log_space_limit into account from now on pthread_mutex_lock(&rli->log_space_lock); rli->ignore_log_space_limit= 0; pthread_mutex_unlock(&rli->log_space_lock); rli->trans_retries= 0; // start from "no error" if (init_relay_log_pos(rli, rli->group_relay_log_name, rli->group_relay_log_pos, 1 /*need data lock*/, &errmsg)) { sql_print_error("Error initializing relay log position: %s", errmsg); goto err; } THD_CHECK_SENTRY(thd); DBUG_ASSERT(rli->event_relay_log_pos >= BIN_LOG_HEADER_SIZE); DBUG_ASSERT(my_b_tell(rli->cur_log) == rli->event_relay_log_pos); DBUG_ASSERT(rli->sql_thd == thd); DBUG_PRINT("master_info",("log_file_name: %s position: %s", rli->group_master_log_name, llstr(rli->group_master_log_pos,llbuff))); if (global_system_variables.log_warnings) sql_print_information("Slave SQL thread initialized, starting replication in \ log '%s' at position %s, relay log '%s' position: %s", RPL_LOG_NAME, llstr(rli->group_master_log_pos,llbuff),rli->group_relay_log_name, llstr(rli->group_relay_log_pos,llbuff1)); /* execute init_slave variable */ if (sys_init_slave.value_length) { execute_init_command(thd, &sys_init_slave, &LOCK_sys_init_slave); if (thd->query_error) { sql_print_error("\ Slave SQL thread aborted. Can't execute init_slave query"); goto err; } } /* Read queries from the IO/THREAD until this thread is killed */ while (!sql_slave_killed(thd,rli)) { thd->proc_info = "Reading event from the relay log"; DBUG_ASSERT(rli->sql_thd == thd); THD_CHECK_SENTRY(thd); if (exec_relay_log_event(thd,rli)) { // do not scare the user if SQL thread was simply killed or stopped if (!sql_slave_killed(thd,rli)) sql_print_error("\ Error running query, slave SQL thread aborted. Fix the problem, and restart \ the slave SQL thread with \"SLAVE START\". We stopped at log \ '%s' position %s", RPL_LOG_NAME, llstr(rli->group_master_log_pos, llbuff)); goto err; } } /* Thread stopped. Print the current replication position to the log */ sql_print_information("Slave SQL thread exiting, replication stopped in log \ '%s' at position %s", RPL_LOG_NAME, llstr(rli->group_master_log_pos,llbuff)); err: VOID(pthread_mutex_lock(&LOCK_thread_count)); thd->query = thd->db = 0; // extra safety thd->query_length= thd->db_length= 0; VOID(pthread_mutex_unlock(&LOCK_thread_count)); thd->proc_info = "Waiting for slave mutex on exit"; pthread_mutex_lock(&rli->run_lock); /* We need data_lock, at least to wake up any waiting master_pos_wait() */ pthread_mutex_lock(&rli->data_lock); DBUG_ASSERT(rli->slave_running == 1); // tracking buffer overrun /* When master_pos_wait() wakes up it will check this and terminate */ rli->slave_running= 0; /* Going out of the transaction. Necessary to mark it, in case the user restarts replication from a non-transactional statement (with CHANGE MASTER). */ /* Wake up master_pos_wait() */ pthread_mutex_unlock(&rli->data_lock); DBUG_PRINT("info",("Signaling possibly waiting master_pos_wait() functions")); pthread_cond_broadcast(&rli->data_cond); rli->ignore_log_space_limit= 0; /* don't need any lock */ rli->save_temporary_tables = thd->temporary_tables; /* TODO: see if we can do this conditionally in next_event() instead to avoid unneeded position re-init */ thd->temporary_tables = 0; // remove tempation from destructor to close them DBUG_ASSERT(thd->net.buff != 0); net_end(&thd->net); // destructor will not free it, because we are weird DBUG_ASSERT(rli->sql_thd == thd); THD_CHECK_SENTRY(thd); rli->sql_thd= 0; pthread_mutex_lock(&LOCK_thread_count); THD_CHECK_SENTRY(thd); delete thd; pthread_mutex_unlock(&LOCK_thread_count); pthread_cond_broadcast(&rli->stop_cond); // tell the world we are done pthread_mutex_unlock(&rli->run_lock); #ifndef DBUG_OFF // TODO: reconsider the code below if (abort_slave_event_count && !rli->events_till_abort) goto slave_begin; #endif my_thread_end(); pthread_exit(0); DBUG_RETURN(0); // Can't return anything here } /* process_io_create_file() */ static int process_io_create_file(MASTER_INFO* mi, Create_file_log_event* cev) { int error = 1; ulong num_bytes; bool cev_not_written; THD *thd = mi->io_thd; NET *net = &mi->mysql->net; DBUG_ENTER("process_io_create_file"); if (unlikely(!cev->is_valid())) DBUG_RETURN(1); /* TODO: fix to honor table rules, not only db rules */ if (!db_ok(cev->db, replicate_do_db, replicate_ignore_db)) { skip_load_data_infile(net); DBUG_RETURN(0); } DBUG_ASSERT(cev->inited_from_old); thd->file_id = cev->file_id = mi->file_id++; thd->server_id = cev->server_id; cev_not_written = 1; if (unlikely(net_request_file(net,cev->fname))) { sql_print_error("Slave I/O: failed requesting download of '%s'", cev->fname); goto err; } /* This dummy block is so we could instantiate Append_block_log_event once and then modify it slightly instead of doing it multiple times in the loop */ { Append_block_log_event aev(thd,0,0,0,0); for (;;) { if (unlikely((num_bytes=my_net_read(net)) == packet_error)) { sql_print_error("Network read error downloading '%s' from master", cev->fname); goto err; } if (unlikely(!num_bytes)) /* eof */ { net_write_command(net, 0, "", 0, "", 0);/* 3.23 master wants it */ /* If we wrote Create_file_log_event, then we need to write Execute_load_log_event. If we did not write Create_file_log_event, then this is an empty file and we can just do as if the LOAD DATA INFILE had not existed, i.e. write nothing. */ if (unlikely(cev_not_written)) break; Execute_load_log_event xev(thd,0,0); xev.log_pos = mi->master_log_pos; if (unlikely(mi->rli.relay_log.append(&xev))) { sql_print_error("Slave I/O: error writing Exec_load event to \ relay log"); goto err; } mi->rli.relay_log.harvest_bytes_written(&mi->rli.log_space_total); break; } if (unlikely(cev_not_written)) { cev->block = (char*)net->read_pos; cev->block_len = num_bytes; cev->log_pos = mi->master_log_pos; if (unlikely(mi->rli.relay_log.append(cev))) { sql_print_error("Slave I/O: error writing Create_file event to \ relay log"); goto err; } cev_not_written=0; mi->rli.relay_log.harvest_bytes_written(&mi->rli.log_space_total); } else { aev.block = (char*)net->read_pos; aev.block_len = num_bytes; aev.log_pos = mi->master_log_pos; if (unlikely(mi->rli.relay_log.append(&aev))) { sql_print_error("Slave I/O: error writing Append_block event to \ relay log"); goto err; } mi->rli.relay_log.harvest_bytes_written(&mi->rli.log_space_total) ; } } } error=0; err: DBUG_RETURN(error); } /* Start using a new binary log on the master SYNOPSIS process_io_rotate() mi master_info for the slave rev The rotate log event read from the binary log DESCRIPTION Updates the master info with the place in the next binary log where we should start reading. NOTES We assume we already locked mi->data_lock RETURN VALUES 0 ok 1 Log event is illegal */ static int process_io_rotate(MASTER_INFO *mi, Rotate_log_event *rev) { DBUG_ENTER("process_io_rotate"); safe_mutex_assert_owner(&mi->data_lock); if (unlikely(!rev->is_valid())) DBUG_RETURN(1); /* Safe copy as 'rev' has been "sanitized" in Rotate_log_event's ctor */ memcpy(mi->master_log_name, rev->new_log_ident, rev->ident_len+1); mi->master_log_pos= rev->pos; DBUG_PRINT("info", ("master_log_pos: '%s' %d", mi->master_log_name, (ulong) mi->master_log_pos)); #ifndef DBUG_OFF /* If we do not do this, we will be getting the first rotate event forever, so we need to not disconnect after one. */ if (disconnect_slave_event_count) events_till_disconnect++; #endif DBUG_RETURN(0); } /* queue_old_event() Writes a 3.23 event to the relay log. TODO: Test this code before release - it has to be tested on a separate setup with 3.23 master */ static int queue_old_event(MASTER_INFO *mi, const char *buf, ulong event_len) { const char *errmsg = 0; ulong inc_pos; bool ignore_event= 0; char *tmp_buf = 0; RELAY_LOG_INFO *rli= &mi->rli; DBUG_ENTER("queue_old_event"); /* If we get Load event, we need to pass a non-reusable buffer to read_log_event, so we do a trick */ if (buf[EVENT_TYPE_OFFSET] == LOAD_EVENT) { if (unlikely(!(tmp_buf=(char*)my_malloc(event_len+1,MYF(MY_WME))))) { sql_print_error("Slave I/O: out of memory for Load event"); DBUG_RETURN(1); } memcpy(tmp_buf,buf,event_len); /* Create_file constructor wants a 0 as last char of buffer, this 0 will serve as the string-termination char for the file's name (which is at the end of the buffer) We must increment event_len, otherwise the event constructor will not see this end 0, which leads to segfault. */ tmp_buf[event_len++]=0; int4store(tmp_buf+EVENT_LEN_OFFSET, event_len); buf = (const char*)tmp_buf; } /* This will transform LOAD_EVENT into CREATE_FILE_EVENT, ask the master to send the loaded file, and write it to the relay log in the form of Append_block/Exec_load (the SQL thread needs the data, as that thread is not connected to the master). */ Log_event *ev = Log_event::read_log_event(buf,event_len, &errmsg, 1 /*old format*/ ); if (unlikely(!ev)) { sql_print_error("Read invalid event from master: '%s',\ master could be corrupt but a more likely cause of this is a bug", errmsg); my_free((char*) tmp_buf, MYF(MY_ALLOW_ZERO_PTR)); DBUG_RETURN(1); } pthread_mutex_lock(&mi->data_lock); ev->log_pos = mi->master_log_pos; switch (ev->get_type_code()) { case STOP_EVENT: ignore_event= 1; inc_pos= event_len; break; case ROTATE_EVENT: if (unlikely(process_io_rotate(mi,(Rotate_log_event*)ev))) { delete ev; pthread_mutex_unlock(&mi->data_lock); DBUG_RETURN(1); } inc_pos= 0; break; case CREATE_FILE_EVENT: /* Yes it's possible to have CREATE_FILE_EVENT here, even if we're in queue_old_event() which is for 3.23 events which don't comprise CREATE_FILE_EVENT. This is because read_log_event() above has just transformed LOAD_EVENT into CREATE_FILE_EVENT. */ { /* We come here when and only when tmp_buf != 0 */ DBUG_ASSERT(tmp_buf); int error = process_io_create_file(mi,(Create_file_log_event*)ev); delete ev; /* We had incremented event_len, but now when it is used to calculate the position in the master's log, we must use the original value. */ mi->master_log_pos += --event_len; DBUG_PRINT("info", ("master_log_pos: %d", (ulong) mi->master_log_pos)); pthread_mutex_unlock(&mi->data_lock); my_free((char*)tmp_buf, MYF(0)); DBUG_RETURN(error); } default: inc_pos= event_len; break; } if (likely(!ignore_event)) { if (unlikely(rli->relay_log.append(ev))) { delete ev; pthread_mutex_unlock(&mi->data_lock); DBUG_RETURN(1); } rli->relay_log.harvest_bytes_written(&rli->log_space_total); } delete ev; mi->master_log_pos+= inc_pos; DBUG_PRINT("info", ("master_log_pos: %d", (ulong) mi->master_log_pos)); pthread_mutex_unlock(&mi->data_lock); DBUG_RETURN(0); } /* queue_event() */ int queue_event(MASTER_INFO* mi,const char* buf, ulong event_len) { int error= 0; ulong inc_pos; RELAY_LOG_INFO *rli= &mi->rli; pthread_mutex_t *log_lock= rli->relay_log.get_log_lock(); DBUG_ENTER("queue_event"); if (mi->old_format) DBUG_RETURN(queue_old_event(mi,buf,event_len)); pthread_mutex_lock(&mi->data_lock); switch (buf[EVENT_TYPE_OFFSET]) { case STOP_EVENT: /* We needn't write this event to the relay log. Indeed, it just indicates a master server shutdown. The only thing this does is cleaning. But cleaning is already done on a per-master-thread basis (as the master server is shutting down cleanly, it has written all DROP TEMPORARY TABLE and DO RELEASE_LOCK; prepared statements' deletion are TODO). We don't even increment mi->master_log_pos, because we may be just after a Rotate event. Btw, in a few milliseconds we are going to have a Start event from the next binlog (unless the master is presently running without --log-bin). */ goto err; case ROTATE_EVENT: { Rotate_log_event rev(buf,event_len,0); if (unlikely(process_io_rotate(mi,&rev))) { error= 1; goto err; } /* Now the I/O thread has just changed its mi->master_log_name, so incrementing mi->master_log_pos is nonsense. */ inc_pos= 0; break; } default: inc_pos= event_len; break; } /* If this event is originating from this server, don't queue it. We don't check this for 3.23 events because it's simpler like this; 3.23 will be filtered anyway by the SQL slave thread which also tests the server id (we must also keep this test in the SQL thread, in case somebody upgrades a 4.0 slave which has a not-filtered relay log). ANY event coming from ourselves can be ignored: it is obvious for queries; for STOP_EVENT/ROTATE_EVENT/START_EVENT: these cannot come from ourselves (--log-slave-updates would not log that) unless this slave is also its direct master (an unsupported, useless setup!). */ pthread_mutex_lock(log_lock); if ((uint4korr(buf + SERVER_ID_OFFSET) == ::server_id) && !replicate_same_server_id) { /* Do not write it to the relay log. a) We still want to increment mi->master_log_pos, so that we won't re-read this event from the master if the slave IO thread is now stopped/restarted (more efficient if the events we are ignoring are big LOAD DATA INFILE). b) We want to record that we are skipping events, for the information of the slave SQL thread, otherwise that thread may let rli->group_relay_log_pos stay too small if the last binlog's event is ignored. */ mi->master_log_pos+= inc_pos; memcpy(rli->ign_master_log_name_end, mi->master_log_name, FN_REFLEN); DBUG_ASSERT(rli->ign_master_log_name_end[0]); rli->ign_master_log_pos_end= mi->master_log_pos; rli->relay_log.signal_update(); // the slave SQL thread needs to re-check DBUG_PRINT("info", ("master_log_pos: %d, event originating from the same server, ignored", (ulong) mi->master_log_pos)); } else { /* write the event to the relay log */ if (likely(!(error= rli->relay_log.appendv(buf,event_len,0)))) { mi->master_log_pos+= inc_pos; DBUG_PRINT("info", ("master_log_pos: %d", (ulong) mi->master_log_pos)); rli->relay_log.harvest_bytes_written(&rli->log_space_total); } rli->ign_master_log_name_end[0]= 0; // last event is not ignored } pthread_mutex_unlock(log_lock); err: pthread_mutex_unlock(&mi->data_lock); DBUG_RETURN(error); } void end_relay_log_info(RELAY_LOG_INFO* rli) { DBUG_ENTER("end_relay_log_info"); if (!rli->inited) DBUG_VOID_RETURN; if (rli->info_fd >= 0) { end_io_cache(&rli->info_file); (void) my_close(rli->info_fd, MYF(MY_WME)); rli->info_fd = -1; } if (rli->cur_log_fd >= 0) { end_io_cache(&rli->cache_buf); (void)my_close(rli->cur_log_fd, MYF(MY_WME)); rli->cur_log_fd = -1; } rli->inited = 0; rli->relay_log.close(LOG_CLOSE_INDEX | LOG_CLOSE_STOP_EVENT); /* Delete the slave's temporary tables from memory. In the future there will be other actions than this, to ensure persistance of slave's temp tables after shutdown. */ rli->close_temporary_tables(); DBUG_VOID_RETURN; } /* Try to connect until successful or slave killed SYNPOSIS safe_connect() thd Thread handler for slave mysql MySQL connection handle mi Replication handle RETURN 0 ok # Error */ static int safe_connect(THD* thd, MYSQL* mysql, MASTER_INFO* mi) { return connect_to_master(thd, mysql, mi, 0, 0); } /* SYNPOSIS connect_to_master() IMPLEMENTATION Try to connect until successful or slave killed or we have retried master_retry_count times */ static int connect_to_master(THD* thd, MYSQL* mysql, MASTER_INFO* mi, bool reconnect, bool suppress_warnings) { int slave_was_killed; int last_errno= -2; // impossible error ulong err_count=0; char llbuff[22]; DBUG_ENTER("connect_to_master"); #ifndef DBUG_OFF events_till_disconnect = disconnect_slave_event_count; #endif ulong client_flag= CLIENT_REMEMBER_OPTIONS; if (opt_slave_compressed_protocol) client_flag=CLIENT_COMPRESS; /* We will use compression */ mysql_options(mysql, MYSQL_OPT_CONNECT_TIMEOUT, (char *) &slave_net_timeout); mysql_options(mysql, MYSQL_OPT_READ_TIMEOUT, (char *) &slave_net_timeout); #ifdef HAVE_OPENSSL if (mi->ssl) mysql_ssl_set(mysql, mi->ssl_key[0]?mi->ssl_key:0, mi->ssl_cert[0]?mi->ssl_cert:0, mi->ssl_ca[0]?mi->ssl_ca:0, mi->ssl_capath[0]?mi->ssl_capath:0, mi->ssl_cipher[0]?mi->ssl_cipher:0); #endif mysql_options(mysql, MYSQL_SET_CHARSET_NAME, default_charset_info->csname); /* This one is not strictly needed but we have it here for completeness */ mysql_options(mysql, MYSQL_SET_CHARSET_DIR, (char *) charsets_dir); while (!(slave_was_killed = io_slave_killed(thd,mi)) && (reconnect ? mysql_reconnect(mysql) != 0 : mysql_real_connect(mysql, mi->host, mi->user, mi->password, 0, mi->port, 0, client_flag) == 0)) { /* Don't repeat last error */ if ((int)mysql_errno(mysql) != last_errno) { last_errno=mysql_errno(mysql); suppress_warnings= 0; sql_print_error("Slave I/O thread: error %s to master \ '%s@%s:%d': \ Error: '%s' errno: %d retry-time: %d retries: %d", (reconnect ? "reconnecting" : "connecting"), mi->user,mi->host,mi->port, mysql_error(mysql), last_errno, mi->connect_retry, master_retry_count); } /* By default we try forever. The reason is that failure will trigger master election, so if the user did not set master_retry_count we do not want to have election triggered on the first failure to connect */ if (++err_count == master_retry_count) { slave_was_killed=1; if (reconnect) change_rpl_status(RPL_ACTIVE_SLAVE,RPL_LOST_SOLDIER); break; } safe_sleep(thd,mi->connect_retry,(CHECK_KILLED_FUNC)io_slave_killed, (void*)mi); } if (!slave_was_killed) { if (reconnect) { if (!suppress_warnings && global_system_variables.log_warnings) sql_print_information("Slave: connected to master '%s@%s:%d',\ replication resumed in log '%s' at position %s", mi->user, mi->host, mi->port, IO_RPL_LOG_NAME, llstr(mi->master_log_pos,llbuff)); } else { change_rpl_status(RPL_IDLE_SLAVE,RPL_ACTIVE_SLAVE); mysql_log.write(thd, COM_CONNECT_OUT, "%s@%s:%d", mi->user, mi->host, mi->port); } #ifdef SIGNAL_WITH_VIO_CLOSE thd->set_active_vio(mysql->net.vio); #endif } DBUG_PRINT("exit",("slave_was_killed: %d", slave_was_killed)); DBUG_RETURN(slave_was_killed); } /* safe_reconnect() IMPLEMENTATION Try to connect until successful or slave killed or we have retried master_retry_count times */ static int safe_reconnect(THD* thd, MYSQL* mysql, MASTER_INFO* mi, bool suppress_warnings) { DBUG_ENTER("safe_reconnect"); DBUG_RETURN(connect_to_master(thd, mysql, mi, 1, suppress_warnings)); } /* Store the file and position where the execute-slave thread are in the relay log. SYNOPSIS flush_relay_log_info() rli Relay log information NOTES - As this is only called by the slave thread, we don't need to have a lock on this. - If there is an active transaction, then we don't update the position in the relay log. This is to ensure that we re-execute statements if we die in the middle of an transaction that was rolled back. - As a transaction never spans binary logs, we don't have to handle the case where we do a relay-log-rotation in the middle of the transaction. If this would not be the case, we would have to ensure that we don't delete the relay log file where the transaction started when we switch to a new relay log file. TODO - Change the log file information to a binary format to avoid calling longlong2str. RETURN VALUES 0 ok 1 write error */ bool flush_relay_log_info(RELAY_LOG_INFO* rli) { bool error=0; IO_CACHE *file = &rli->info_file; char buff[FN_REFLEN*2+22*2+4], *pos; my_b_seek(file, 0L); pos=strmov(buff, rli->group_relay_log_name); *pos++='\n'; pos=longlong2str(rli->group_relay_log_pos, pos, 10); *pos++='\n'; pos=strmov(pos, rli->group_master_log_name); *pos++='\n'; pos=longlong2str(rli->group_master_log_pos, pos, 10); *pos='\n'; if (my_b_write(file, (byte*) buff, (ulong) (pos-buff)+1)) error=1; if (flush_io_cache(file)) error=1; /* Flushing the relay log is done by the slave I/O thread */ return error; } /* Called when we notice that the current "hot" log got rotated under our feet. */ static IO_CACHE *reopen_relay_log(RELAY_LOG_INFO *rli, const char **errmsg) { DBUG_ASSERT(rli->cur_log != &rli->cache_buf); DBUG_ASSERT(rli->cur_log_fd == -1); DBUG_ENTER("reopen_relay_log"); IO_CACHE *cur_log = rli->cur_log=&rli->cache_buf; if ((rli->cur_log_fd=open_binlog(cur_log,rli->event_relay_log_name, errmsg)) <0) DBUG_RETURN(0); /* We want to start exactly where we was before: relay_log_pos Current log pos pending Number of bytes already processed from the event */ my_b_seek(cur_log,rli->event_relay_log_pos); DBUG_RETURN(cur_log); } Log_event* next_event(RELAY_LOG_INFO* rli) { Log_event* ev; IO_CACHE* cur_log = rli->cur_log; pthread_mutex_t *log_lock = rli->relay_log.get_log_lock(); const char* errmsg=0; THD* thd = rli->sql_thd; DBUG_ENTER("next_event"); DBUG_ASSERT(thd != 0); /* For most operations we need to protect rli members with data_lock, so we assume calling function acquired this mutex for us and we will hold it for the most of the loop below However, we will release it whenever it is worth the hassle, and in the cases when we go into a pthread_cond_wait() with the non-data_lock mutex */ safe_mutex_assert_owner(&rli->data_lock); while (!sql_slave_killed(thd,rli)) { /* We can have two kinds of log reading: hot_log: rli->cur_log points at the IO_CACHE of relay_log, which is actively being updated by the I/O thread. We need to be careful in this case and make sure that we are not looking at a stale log that has already been rotated. If it has been, we reopen the log. The other case is much simpler: We just have a read only log that nobody else will be updating. */ bool hot_log; if ((hot_log = (cur_log != &rli->cache_buf))) { DBUG_ASSERT(rli->cur_log_fd == -1); // foreign descriptor pthread_mutex_lock(log_lock); /* Reading xxx_file_id is safe because the log will only be rotated when we hold relay_log.LOCK_log */ if (rli->relay_log.get_open_count() != rli->cur_log_old_open_count) { // The master has switched to a new log file; Reopen the old log file cur_log=reopen_relay_log(rli, &errmsg); pthread_mutex_unlock(log_lock); if (!cur_log) // No more log files goto err; hot_log=0; // Using old binary log } } #ifndef DBUG_OFF { char llbuf1[22], llbuf2[22]; DBUG_ASSERT(my_b_tell(cur_log) >= BIN_LOG_HEADER_SIZE); /* The next assertion sometimes (very rarely) fails, let's try to track it */ DBUG_PRINT("info", ("\ Before assert, my_b_tell(cur_log)=%s rli->event_relay_log_pos=%s", llstr(my_b_tell(cur_log),llbuf1), llstr(rli->group_relay_log_pos,llbuf2))); DBUG_ASSERT(my_b_tell(cur_log) == rli->event_relay_log_pos); } #endif /* Relay log is always in new format - if the master is 3.23, the I/O thread will convert the format for us */ if ((ev=Log_event::read_log_event(cur_log,0,(bool)0 /* new format */))) { DBUG_ASSERT(thd==rli->sql_thd); if (hot_log) pthread_mutex_unlock(log_lock); DBUG_RETURN(ev); } DBUG_ASSERT(thd==rli->sql_thd); if (opt_reckless_slave) // For mysql-test cur_log->error = 0; if (cur_log->error < 0) { errmsg = "slave SQL thread aborted because of I/O error"; if (hot_log) pthread_mutex_unlock(log_lock); goto err; } if (!cur_log->error) /* EOF */ { /* On a hot log, EOF means that there are no more updates to process and we must block until I/O thread adds some and signals us to continue */ if (hot_log) { /* We say in Seconds_Behind_Master that we have "caught up". Note that for example if network link is broken but I/O slave thread hasn't noticed it (slave_net_timeout not elapsed), then we'll say "caught up" whereas we're not really caught up. Fixing that would require internally cutting timeout in smaller pieces in network read, no thanks. Another example: SQL has caught up on I/O, now I/O has read a new event and is queuing it; the false "0" will exist until SQL finishes executing the new event; it will be look abnormal only if the events have old timestamps (then you get "many", 0, "many"). Transient phases like this can't really be fixed. */ time_t save_timestamp= rli->last_master_timestamp; rli->last_master_timestamp= 0; DBUG_ASSERT(rli->relay_log.get_open_count() == rli->cur_log_old_open_count); if (rli->ign_master_log_name_end[0]) { /* We generate and return a Rotate, to make our positions advance */ DBUG_PRINT("info",("seeing an ignored end segment")); ev= new Rotate_log_event(thd, rli->ign_master_log_name_end, 0, rli->ign_master_log_pos_end, Rotate_log_event::DUP_NAME | Rotate_log_event::ZERO_LEN); rli->ign_master_log_name_end[0]= 0; pthread_mutex_unlock(log_lock); if (unlikely(!ev)) { errmsg= "Slave SQL thread failed to create a Rotate event " "(out of memory?), SHOW SLAVE STATUS may be inaccurate"; goto err; } ev->server_id= 0; // don't be ignored by slave SQL thread DBUG_RETURN(ev); } /* We can, and should release data_lock while we are waiting for update. If we do not, show slave status will block */ pthread_mutex_unlock(&rli->data_lock); /* Possible deadlock : - the I/O thread has reached log_space_limit - the SQL thread has read all relay logs, but cannot purge for some reason: * it has already purged all logs except the current one * there are other logs than the current one but they're involved in a transaction that finishes in the current one (or is not finished) Solution : Wake up the possibly waiting I/O thread, and set a boolean asking the I/O thread to temporarily ignore the log_space_limit constraint, because we do not want the I/O thread to block because of space (it's ok if it blocks for any other reason (e.g. because the master does not send anything). Then the I/O thread stops waiting and reads more events. The SQL thread decides when the I/O thread should take log_space_limit into account again : ignore_log_space_limit is reset to 0 in purge_first_log (when the SQL thread purges the just-read relay log), and also when the SQL thread starts. We should also reset ignore_log_space_limit to 0 when the user does RESET SLAVE, but in fact, no need as RESET SLAVE requires that the slave be stopped, and the SQL thread sets ignore_log_space_limit to 0 when it stops. */ pthread_mutex_lock(&rli->log_space_lock); // prevent the I/O thread from blocking next times rli->ignore_log_space_limit= 1; /* If the I/O thread is blocked, unblock it. Ok to broadcast after unlock, because the mutex is only destroyed in ~st_relay_log_info(), i.e. when rli is destroyed, and rli will not be destroyed before we exit the present function. */ pthread_mutex_unlock(&rli->log_space_lock); pthread_cond_broadcast(&rli->log_space_cond); // Note that wait_for_update unlocks lock_log ! rli->relay_log.wait_for_update(rli->sql_thd, 1); // re-acquire data lock since we released it earlier pthread_mutex_lock(&rli->data_lock); rli->last_master_timestamp= save_timestamp; continue; } /* If the log was not hot, we need to move to the next log in sequence. The next log could be hot or cold, we deal with both cases separately after doing some common initialization */ end_io_cache(cur_log); DBUG_ASSERT(rli->cur_log_fd >= 0); my_close(rli->cur_log_fd, MYF(MY_WME)); rli->cur_log_fd = -1; if (relay_log_purge) { /* purge_first_log will properly set up relay log coordinates in rli. If the group's coordinates are equal to the event's coordinates (i.e. the relay log was not rotated in the middle of a group), we can purge this relay log too. We do ulonglong and string comparisons, this may be slow but - purging the last relay log is nice (it can save 1GB of disk), so we like to detect the case where we can do it, and given this, - I see no better detection method - purge_first_log is not called that often */ if (rli->relay_log.purge_first_log (rli, rli->group_relay_log_pos == rli->event_relay_log_pos && !strcmp(rli->group_relay_log_name,rli->event_relay_log_name))) { errmsg = "Error purging processed logs"; goto err; } } else { /* If hot_log is set, then we already have a lock on LOCK_log. If not, we have to get the lock. According to Sasha, the only time this code will ever be executed is if we are recovering from a bug. */ if (rli->relay_log.find_next_log(&rli->linfo, !hot_log)) { errmsg = "error switching to the next log"; goto err; } rli->event_relay_log_pos = BIN_LOG_HEADER_SIZE; strmake(rli->event_relay_log_name,rli->linfo.log_file_name, sizeof(rli->event_relay_log_name)-1); flush_relay_log_info(rli); } /* Now we want to open this next log. To know if it's a hot log (the one being written by the I/O thread now) or a cold log, we can use is_active(); if it is hot, we use the I/O cache; if it's cold we open the file normally. But if is_active() reports that the log is hot, this may change between the test and the consequence of the test. So we may open the I/O cache whereas the log is now cold, which is nonsense. To guard against this, we need to have LOCK_log. */ DBUG_PRINT("info",("hot_log: %d",hot_log)); if (!hot_log) /* if hot_log, we already have this mutex */ pthread_mutex_lock(log_lock); if (rli->relay_log.is_active(rli->linfo.log_file_name)) { #ifdef EXTRA_DEBUG if (global_system_variables.log_warnings) sql_print_error("next log '%s' is currently active", rli->linfo.log_file_name); #endif rli->cur_log= cur_log= rli->relay_log.get_log_file(); rli->cur_log_old_open_count= rli->relay_log.get_open_count(); DBUG_ASSERT(rli->cur_log_fd == -1); /* Read pointer has to be at the start since we are the only reader. We must keep the LOCK_log to read the 4 first bytes, as this is a hot log (same as when we call read_log_event() above: for a hot log we take the mutex). */ if (check_binlog_magic(cur_log,&errmsg)) { if (!hot_log) pthread_mutex_unlock(log_lock); goto err; } if (!hot_log) pthread_mutex_unlock(log_lock); continue; } if (!hot_log) pthread_mutex_unlock(log_lock); /* if we get here, the log was not hot, so we will have to open it ourselves. We are sure that the log is still not hot now (a log can get from hot to cold, but not from cold to hot). No need for LOCK_log. */ #ifdef EXTRA_DEBUG if (global_system_variables.log_warnings) sql_print_error("next log '%s' is not active", rli->linfo.log_file_name); #endif // open_binlog() will check the magic header if ((rli->cur_log_fd=open_binlog(cur_log,rli->linfo.log_file_name, &errmsg)) <0) goto err; } else { /* Read failed with a non-EOF error. TODO: come up with something better to handle this error */ if (hot_log) pthread_mutex_unlock(log_lock); sql_print_error("Slave SQL thread: I/O error reading \ event(errno: %d cur_log->error: %d)", my_errno,cur_log->error); // set read position to the beginning of the event my_b_seek(cur_log,rli->event_relay_log_pos); /* otherwise, we have had a partial read */ errmsg = "Aborting slave SQL thread because of partial event read"; break; // To end of function } } if (!errmsg && global_system_variables.log_warnings) errmsg = "slave SQL thread was killed"; err: if (errmsg) sql_print_error("Error reading relay log event: %s", errmsg); DBUG_RETURN(0); } /* Rotate a relay log (this is used only by FLUSH LOGS; the automatic rotation because of size is simpler because when we do it we already have all relevant locks; here we don't, so this function is mainly taking locks). Returns nothing as we cannot catch any error (MYSQL_LOG::new_file() is void). */ void rotate_relay_log(MASTER_INFO* mi) { DBUG_ENTER("rotate_relay_log"); RELAY_LOG_INFO* rli= &mi->rli; lock_slave_threads(mi); pthread_mutex_lock(&mi->data_lock); pthread_mutex_lock(&rli->data_lock); /* We need to test inited because otherwise, new_file() will attempt to lock LOCK_log, which may not be inited (if we're not a slave). */ if (!rli->inited) { DBUG_PRINT("info", ("rli->inited == 0")); goto end; } /* If the relay log is closed, new_file() will do nothing. */ rli->relay_log.new_file(1); /* We harvest now, because otherwise BIN_LOG_HEADER_SIZE will not immediately be counted, so imagine a succession of FLUSH LOGS and assume the slave threads are started: relay_log_space decreases by the size of the deleted relay log, but does not increase, so flush-after-flush we may become negative, which is wrong. Even if this will be corrected as soon as a query is replicated on the slave (because the I/O thread will then call harvest_bytes_written() which will harvest all these BIN_LOG_HEADER_SIZE we forgot), it may give strange output in SHOW SLAVE STATUS meanwhile. So we harvest now. If the log is closed, then this will just harvest the last writes, probably 0 as they probably have been harvested. */ rli->relay_log.harvest_bytes_written(&rli->log_space_total); end: pthread_mutex_unlock(&rli->data_lock); pthread_mutex_unlock(&mi->data_lock); unlock_slave_threads(mi); DBUG_VOID_RETURN; } #ifdef __GNUC__ template class I_List_iterator; template class I_List_iterator; #endif #endif /* HAVE_REPLICATION */