/* 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; version 2 of the License. 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" #include "rpl_mi.h" #include "rpl_rli.h" #include // For MY_STAT #include "sql_repl.h" // For check_binlog_magic #include "rpl_utility.h" static int count_relay_log_space(RELAY_LOG_INFO* rli); // Defined in slave.cc int init_intvar_from_file(int* var, IO_CACHE* f, int default_val); int init_strvar_from_file(char *var, int max_size, IO_CACHE *f, const char *default_val); st_relay_log_info::st_relay_log_info() :no_storage(FALSE), replicate_same_server_id(::replicate_same_server_id), 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), tables_to_lock(0), tables_to_lock_count(0), last_event_start_time(0), m_flags(0) { DBUG_ENTER("st_relay_log_info::st_relay_log_info"); 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)); cached_charset_invalidate(); 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(); DBUG_VOID_RETURN; } st_relay_log_info::~st_relay_log_info() { DBUG_ENTER("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); relay_log.cleanup(); 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"); DBUG_ASSERT(!rli->no_storage); // Don't init if there is no storage 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; rli->tables_to_lock= 0; rli->tables_to_lock_count= 0; /* 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). */ { char buf[FN_REFLEN]; const char *ln; static bool name_warning_sent= 0; ln= rli->relay_log.generate_name(opt_relay_logname, "-relay-bin", 1, buf); /* We send the warning only at startup, not after every RESET SLAVE */ if (!opt_relay_logname && !opt_relaylog_index_name && !name_warning_sent) { /* User didn't give us info to name the relay log index file. Picking `hostname`-relay-bin.index like we do, causes replication to fail if this slave's hostname is changed later. So, we would like to instead require a name. But as we don't want to break many existing setups, we only give warning, not error. */ sql_print_warning("Neither --relay-log nor --relay-log-index were used;" " so replication " "may break when this MySQL server acts as a " "slave and has his hostname changed!! Please " "use '--relay-log=%s' to avoid this problem.", ln); name_warning_sent= 1; } /* note, that if open() fails, we'll still have index file open but a destructor will take care of that */ if (rli->relay_log.open_index_file(opt_relaylog_index_name, ln) || rli->relay_log.open(ln, LOG_BIN, 0, SEQ_READ_APPEND, 0, (max_relay_log_size ? max_relay_log_size : max_binlog_size), 1)) { 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, 0)) { 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, 0)) { 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; } } #ifndef DBUG_OFF { char llbuf1[22], llbuf2[22]; DBUG_PRINT("info", ("my_b_tell(rli->cur_log)=%s rli->event_relay_log_pos=%s", llstr(my_b_tell(rli->cur_log),llbuf1), llstr(rli->event_relay_log_pos,llbuf2))); DBUG_ASSERT(rli->event_relay_log_pos >= BIN_LOG_HEADER_SIZE); DBUG_ASSERT(my_b_tell(rli->cur_log) == rli->event_relay_log_pos); } #endif /* 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 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); } void st_relay_log_info::clear_slave_error() { DBUG_ENTER("clear_slave_error"); /* Clear the errors displayed by SHOW SLAVE STATUS */ last_slave_error[0]= 0; last_slave_errno= 0; DBUG_VOID_RETURN; } /* Reset UNTIL condition for RELAY_LOG_INFO SYNOPSYS clear_until_condition() rli - RELAY_LOG_INFO structure where UNTIL condition should be reset */ void st_relay_log_info::clear_until_condition() { DBUG_ENTER("clear_until_condition"); until_condition= RELAY_LOG_INFO::UNTIL_NONE; until_log_name[0]= 0; until_log_pos= 0; DBUG_VOID_RETURN; } /* 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 look_for_description_event 1 if we should look for such an event. We only need this when the SQL thread starts and opens an existing relay log and has to execute it (possibly from an offset >4); then we need to read the first event of the relay log to be able to parse the events we have to execute. 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, bool look_for_description_event) { DBUG_ENTER("init_relay_log_pos"); DBUG_PRINT("info", ("pos: %lu", (ulong) pos)); *errmsg=0; pthread_mutex_t *log_lock=rli->relay_log.get_log_lock(); if (need_data_lock) pthread_mutex_lock(&rli->data_lock); /* Slave threads are not the only users of init_relay_log_pos(). CHANGE MASTER is, too, and init_slave() too; these 2 functions allocate a description event in init_relay_log_pos, which is not freed by the terminating SQL slave thread as that thread is not started by these functions. So we have to free the description_event here, in case, so that there is no memory leak in running, say, CHANGE MASTER. */ delete rli->relay_log.description_event_for_exec; /* By default the relay log is in binlog format 3 (4.0). Even if format is 4, this will work enough to read the first event (Format_desc) (remember that format 4 is just lenghtened compared to format 3; format 3 is a prefix of format 4). */ rli->relay_log.description_event_for_exec= new Format_description_log_event(3); 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. */ my_b_seek((rli->cur_log=rli->relay_log.get_log_file()), (off_t)0); if (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; } /* In all cases, check_binlog_magic() has been called so we're at offset 4 for sure. */ if (pos > BIN_LOG_HEADER_SIZE) /* If pos<=4, we stay at 4 */ { Log_event* ev; while (look_for_description_event) { /* Read the possible Format_description_log_event; if position was 4, no need, it will be read naturally. */ DBUG_PRINT("info",("looking for a Format_description_log_event")); if (my_b_tell(rli->cur_log) >= pos) break; /* Because of we have rli->data_lock and log_lock, we can safely read an event */ if (!(ev=Log_event::read_log_event(rli->cur_log,0, rli->relay_log.description_event_for_exec))) { DBUG_PRINT("info",("could not read event, rli->cur_log->error=%d", rli->cur_log->error)); if (rli->cur_log->error) /* not EOF */ { *errmsg= "I/O error reading event at position 4"; goto err; } break; } else if (ev->get_type_code() == FORMAT_DESCRIPTION_EVENT) { DBUG_PRINT("info",("found Format_description_log_event")); delete rli->relay_log.description_event_for_exec; rli->relay_log.description_event_for_exec= (Format_description_log_event*) ev; /* As ev was returned by read_log_event, it has passed is_valid(), so my_malloc() in ctor worked, no need to check again. */ /* Ok, we found a Format_description event. But it is not sure that this describes the whole relay log; indeed, one can have this sequence (starting from position 4): Format_desc (of slave) Rotate (of master) Format_desc (of master) So the Format_desc which really describes the rest of the relay log is the 3rd event (it can't be further than that, because we rotate the relay log when we queue a Rotate event from the master). But what describes the Rotate is the first Format_desc. So what we do is: go on searching for Format_description events, until you exceed the position (argument 'pos') or until you find another event than Rotate or Format_desc. */ } else { DBUG_PRINT("info",("found event of another type=%d", ev->get_type_code())); look_for_description_event= (ev->get_type_code() == ROTATE_EVENT); delete ev; } } my_b_seek(rli->cur_log,(off_t)pos); #ifndef DBUG_OFF { char llbuf1[22], llbuf2[22]; DBUG_PRINT("info", ("my_b_tell(rli->cur_log)=%s rli->event_relay_log_pos=%s", llstr(my_b_tell(rli->cur_log),llbuf1), llstr(rli->event_relay_log_pos,llbuf2))); } #endif } 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); if (!rli->relay_log.description_event_for_exec->is_valid() && !*errmsg) *errmsg= "Invalid Format_description log event; could be out of memory"; DBUG_RETURN ((*errmsg) ? 1 : 0); } /* 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) { int event_count = 0; ulong init_abort_pos_wait; int error=0; struct timespec abstime; // for timeout checking const char *msg; DBUG_ENTER("st_relay_log_info::wait_for_pos"); if (!inited) DBUG_RETURN(-1); DBUG_PRINT("enter",("log_name: '%s' log_pos: %lu timeout: %lu", log_name->c_ptr(), (ulong) log_pos, (ulong) timeout)); set_timespec(abstime,timeout); pthread_mutex_lock(&data_lock); 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; DBUG_PRINT("info", ("init_abort_pos_wait: %ld abort_pos_wait: %ld", init_abort_pos_wait, abort_pos_wait)); DBUG_PRINT("info",("group_master_log_name: '%s' pos: %lu", group_master_log_name, (ulong) group_master_log_pos)); /* 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", thd->killed_errno(), (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 ); } void st_relay_log_info::inc_group_relay_log_pos(ulonglong log_pos, bool skip_lock) { DBUG_ENTER("st_relay_log_info::inc_group_relay_log_pos"); if (!skip_lock) pthread_mutex_lock(&data_lock); inc_event_relay_log_pos(); 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). */ /* In 4.x we used the event's len to compute the positions here. This is wrong if the event was 3.23/4.0 and has been converted to 5.0, because then the event's len is not what is was in the master's binlog, so this will make a wrong group_master_log_pos (yes it's a bug in 3.23->4.0 replication: Exec_master_log_pos is wrong). Only way to solve this is to have the original offset of the end of the event the relay log. This is what we do in 5.0: log_pos has become "end_log_pos" (because the real use of log_pos in 4.0 was to compute the end_log_pos; so better to store end_log_pos instead of begin_log_pos. If we had not done this fix here, the problem would also have appeared when the slave and master are 5.0 but with different event length (for example the slave is more recent than the master and features the event UID). It would give false MASTER_POS_WAIT, false Exec_master_log_pos in SHOW SLAVE STATUS, and so the user would do some CHANGE MASTER using this value which would lead to badly broken replication. Even the relay_log_pos will be corrupted in this case, because the len is the relay log is not "val". With the end_log_pos solution, we avoid computations involving lengthes. */ DBUG_PRINT("info", ("log_pos: %lu group_master_log_pos: %lu", (long) log_pos, (long) group_master_log_pos)); if (log_pos) // 3.23 binlogs don't have log_posx { group_master_log_pos= log_pos; } pthread_cond_broadcast(&data_cond); if (!skip_lock) pthread_mutex_unlock(&data_lock); DBUG_VOID_RETURN; } void st_relay_log_info::close_temporary_tables() { TABLE *table,*next; DBUG_ENTER("st_relay_log_info::close_temporary_tables"); 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. */ DBUG_PRINT("info", ("table: 0x%lx", (long) table)); close_temporary(table, 1, 0); } save_temporary_tables= 0; slave_open_temp_tables= 0; DBUG_VOID_RETURN; } /* 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); /* we close the relay log fd possibly left open by the slave SQL thread, to be able to delete it; the relay log fd possibly left open by the slave I/O thread will be closed naturally in reset_logs() by the close(LOG_CLOSE_TO_BE_OPENED) call */ 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; } 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); rli->group_relay_log_pos= rli->event_relay_log_pos= BIN_LOG_HEADER_SIZE; if (count_relay_log_space(rli)) { *errmsg= "Error counting relay log space"; goto err; } 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, 0); 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); } /* 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::do_apply_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_ENTER("st_relay_log_info::is_until_satisfied"); 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; } #ifndef DBUG_OFF { char buf[32]; DBUG_PRINT("info", ("group_master_log_name='%s', group_master_log_pos=%s", group_master_log_name, llstr(group_master_log_pos, buf))); DBUG_PRINT("info", ("group_relay_log_name='%s', group_relay_log_pos=%s", group_relay_log_name, llstr(group_relay_log_pos, buf))); DBUG_PRINT("info", ("(%s) log_name='%s', log_pos=%s", until_condition == UNTIL_MASTER_POS ? "master" : "relay", log_name, llstr(log_pos, buf))); DBUG_PRINT("info", ("(%s) until_log_name='%s', until_log_pos=%s", until_condition == UNTIL_MASTER_POS ? "master" : "relay", until_log_name, llstr(until_log_pos, buf))); } #endif if (until_log_names_cmp_result == UNTIL_LOG_NAMES_CMP_UNKNOWN) { /* We have no cached comparison results so we should compare log names and cache result. If we are after RESET SLAVE, and the SQL slave thread has not processed any event yet, it could be that group_master_log_name is "". In that case, just wait for more events (as there is no sensible comparison to do). */ 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."); DBUG_RETURN(TRUE); } } else DBUG_RETURN(until_log_pos == 0); } DBUG_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)); } void st_relay_log_info::cached_charset_invalidate() { DBUG_ENTER("st_relay_log_info::cached_charset_invalidate"); /* Full of zeroes means uninitialized. */ bzero(cached_charset, sizeof(cached_charset)); DBUG_VOID_RETURN; } bool st_relay_log_info::cached_charset_compare(char *charset) const { DBUG_ENTER("st_relay_log_info::cached_charset_compare"); if (bcmp(cached_charset, charset, sizeof(cached_charset))) { memcpy(const_cast(cached_charset), charset, sizeof(cached_charset)); DBUG_RETURN(1); } DBUG_RETURN(0); } void st_relay_log_info::stmt_done(my_off_t event_master_log_pos, time_t event_creation_time) { clear_flag(IN_STMT); /* If in a transaction, and if the slave supports transactions, just inc_event_relay_log_pos(). We only have to check for OPTION_BEGIN (not OPTION_NOT_AUTOCOMMIT) as transactions are logged with BEGIN/COMMIT, not with SET AUTOCOMMIT= . CAUTION: opt_using_transactions means innodb || bdb ; suppose the master supports InnoDB and BDB, but the slave supports only BDB, problems will arise: - suppose an InnoDB table is created on the master, - then it will be MyISAM on the slave - but as opt_using_transactions is true, the slave will believe he is transactional with the MyISAM table. And problems will come when one does START SLAVE; STOP SLAVE; START SLAVE; (the slave will resume at BEGIN whereas there has not been any rollback). This is the problem of using opt_using_transactions instead of a finer "does the slave support _transactional handler used on the master_". More generally, we'll have problems when a query mixes a transactional handler and MyISAM and STOP SLAVE is issued in the middle of the "transaction". START SLAVE will resume at BEGIN while the MyISAM table has already been updated. */ if ((sql_thd->options & OPTION_BEGIN) && opt_using_transactions) inc_event_relay_log_pos(); else { inc_group_relay_log_pos(event_master_log_pos); flush_relay_log_info(this); /* Note that Rotate_log_event::do_apply_event() does not call this function, so there is no chance that a fake rotate event resets last_master_timestamp. Note that we update without mutex (probably ok - except in some very rare cases, only consequence is that value may take some time to display in Seconds_Behind_Master - not critical). */ last_master_timestamp= event_creation_time; } } #if !defined(MYSQL_CLIENT) && defined(HAVE_REPLICATION) void st_relay_log_info::cleanup_context(THD *thd, bool error) { DBUG_ENTER("st_relay_log_info::cleanup_context"); DBUG_ASSERT(sql_thd == thd); /* 1) Instances of Table_map_log_event, if ::do_apply_event() was called on them, may have opened tables, which we cannot be sure have been closed (because maybe the Rows_log_event have not been found or will not be, because slave SQL thread is stopping, or relay log has a missing tail etc). So we close all thread's tables. And so the table mappings have to be cancelled. 2) Rows_log_event::do_apply_event() may even have started statements or transactions on them, which we need to rollback in case of error. 3) If finding a Format_description_log_event after a BEGIN, we also need to rollback before continuing with the next events. 4) so we need this "context cleanup" function. */ if (error) { ha_autocommit_or_rollback(thd, 1); // if a "statement transaction" end_trans(thd, ROLLBACK); // if a "real transaction" } m_table_map.clear_tables(); close_thread_tables(thd); clear_tables_to_lock(); clear_flag(IN_STMT); last_event_start_time= 0; DBUG_VOID_RETURN; } void st_relay_log_info::clear_tables_to_lock() { while (tables_to_lock) { gptr to_free= reinterpret_cast(tables_to_lock); if (tables_to_lock->m_tabledef_valid) { tables_to_lock->m_tabledef.table_def::~table_def(); tables_to_lock->m_tabledef_valid= FALSE; } tables_to_lock= static_cast(tables_to_lock->next_global); tables_to_lock_count--; my_free(to_free, MYF(MY_WME)); } DBUG_ASSERT(tables_to_lock == NULL && tables_to_lock_count == 0); } #endif