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/* Copyright (C) 2000-2003 MySQL AB
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
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#include <my_global.h> // For HAVE_REPLICATION
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#include "mysql_priv.h"
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#ifdef HAVE_REPLICATION
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#define DEFAULT_CONNECT_RETRY 60
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// Defined in slave.cc
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int init_intvar_from_file(int* var, IO_CACHE* f, int default_val);
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int init_strvar_from_file(char *var, int max_size, IO_CACHE *f,
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const char *default_val);
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int init_floatvar_from_file(float* var, IO_CACHE* f, float default_val);
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Master_info::Master_info()
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:Slave_reporting_capability("I/O"),
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ssl(0), ssl_verify_server_cert(0), fd(-1), io_thd(0), port(MYSQL_PORT),
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connect_retry(DEFAULT_CONNECT_RETRY), heartbeat_period(0),
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received_heartbeats(0), inited(0),
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abort_slave(0), slave_running(0), slave_run_id(0)
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host[0] = 0; user[0] = 0; password[0] = 0;
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ssl_ca[0]= 0; ssl_capath[0]= 0; ssl_cert[0]= 0;
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ssl_cipher[0]= 0; ssl_key[0]= 0;
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bzero((char*) &file, sizeof(file));
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pthread_mutex_init(&run_lock, MY_MUTEX_INIT_FAST);
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pthread_mutex_init(&data_lock, MY_MUTEX_INIT_FAST);
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pthread_cond_init(&data_cond, NULL);
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pthread_cond_init(&start_cond, NULL);
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pthread_cond_init(&stop_cond, NULL);
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Master_info::~Master_info()
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pthread_mutex_destroy(&run_lock);
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pthread_mutex_destroy(&data_lock);
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pthread_cond_destroy(&data_cond);
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pthread_cond_destroy(&start_cond);
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pthread_cond_destroy(&stop_cond);
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void init_master_log_pos(Master_info* mi)
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DBUG_ENTER("init_master_log_pos");
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mi->master_log_name[0] = 0;
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mi->master_log_pos = BIN_LOG_HEADER_SIZE; // skip magic number
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always request heartbeat unless master_heartbeat_period is set
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explicitly zero. Here is the default value for heartbeat period
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if CHANGE MASTER did not specify it. (no data loss in conversion
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as hb period has a max)
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mi->heartbeat_period= (float) min(SLAVE_MAX_HEARTBEAT_PERIOD,
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(slave_net_timeout/2.0));
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DBUG_ASSERT(mi->heartbeat_period > (float) 0.001
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|| mi->heartbeat_period == 0);
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LINES_IN_MASTER_INFO_WITH_SSL= 14,
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/* 5.1.16 added value of master_ssl_verify_server_cert */
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LINE_FOR_MASTER_SSL_VERIFY_SERVER_CERT= 15,
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/* 6.0 added value of master_heartbeat_period */
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LINE_FOR_MASTER_HEARTBEAT_PERIOD= 16,
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/* Number of lines currently used when saving master info file */
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LINES_IN_MASTER_INFO= LINE_FOR_MASTER_HEARTBEAT_PERIOD
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int init_master_info(Master_info* mi, const char* master_info_fname,
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const char* slave_info_fname,
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bool abort_if_no_master_info_file,
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char fname[FN_REFLEN+128];
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DBUG_ENTER("init_master_info");
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We have to reset read position of relay-log-bin as we may have
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already been reading from 'hotlog' when the slave was stopped
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last time. If this case pos_in_file would be set and we would
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get a crash when trying to read the signature for the binary
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We only rewind the read position if we are starting the SQL
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thread. The handle_slave_sql thread assumes that the read
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position is at the beginning of the file, and will read the
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"signature" and then fast-forward to the last position read.
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if (thread_mask & SLAVE_SQL)
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my_b_seek(mi->rli.cur_log, (my_off_t) 0);
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fn_format(fname, master_info_fname, mysql_data_home, "", 4+32);
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We need a mutex while we are changing master info parameters to
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keep other threads from reading bogus info
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pthread_mutex_lock(&mi->data_lock);
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/* does master.info exist ? */
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if (access(fname,F_OK))
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if (abort_if_no_master_info_file)
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pthread_mutex_unlock(&mi->data_lock);
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if someone removed the file from underneath our feet, just close
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the old descriptor and re-create the old file
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my_close(fd, MYF(MY_WME));
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if ((fd = my_open(fname, O_CREAT|O_RDWR|O_BINARY, MYF(MY_WME))) < 0 )
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sql_print_error("Failed to create a new master info file (file '%s', errno %d)", fname, my_errno);
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if (init_io_cache(&mi->file, fd, IO_SIZE*2, READ_CACHE, 0L,0,
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sql_print_error("Failed to create a cache on master info file (file '%s')", fname);
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init_master_log_pos(mi);
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reinit_io_cache(&mi->file, READ_CACHE, 0L,0,0);
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if ((fd = my_open(fname, O_RDWR|O_BINARY, MYF(MY_WME))) < 0 )
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sql_print_error("Failed to open the existing master info file (file '%s', errno %d)", fname, my_errno);
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if (init_io_cache(&mi->file, fd, IO_SIZE*2, READ_CACHE, 0L,
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sql_print_error("Failed to create a cache on master info file (file '%s')", fname);
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int port, connect_retry, master_log_pos, lines;
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int ssl= 0, ssl_verify_server_cert= 0;
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float master_heartbeat_period= 0.0;
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char *first_non_digit;
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Starting from 4.1.x master.info has new format. Now its
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first line contains number of lines in file. By reading this
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number we will be always distinguish to which version our
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master.info corresponds to. We can't simply count lines in
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file since versions before 4.1.x could generate files with more
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If first line doesn't contain a number or contain number less than
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LINES_IN_MASTER_INFO_WITH_SSL then such file is treated like file
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from pre 4.1.1 version.
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There is no ambiguity when reading an old master.info, as before
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4.1.1, the first line contained the binlog's name, which is either
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empty or has an extension (contains a '.'), so can't be confused
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So we're just reading first line and trying to figure which version
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The first row is temporarily stored in mi->master_log_name,
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if it is line count and not binlog name (new format) it will be
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overwritten by the second row later.
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if (init_strvar_from_file(mi->master_log_name,
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sizeof(mi->master_log_name), &mi->file,
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lines= strtoul(mi->master_log_name, &first_non_digit, 10);
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if (mi->master_log_name[0]!='\0' &&
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*first_non_digit=='\0' && lines >= LINES_IN_MASTER_INFO_WITH_SSL)
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/* Seems to be new format => read master log name from next line */
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if (init_strvar_from_file(mi->master_log_name,
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sizeof(mi->master_log_name), &mi->file, ""))
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if (init_intvar_from_file(&master_log_pos, &mi->file, 4) ||
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init_strvar_from_file(mi->host, sizeof(mi->host), &mi->file, 0) ||
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init_strvar_from_file(mi->user, sizeof(mi->user), &mi->file, "test") ||
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init_strvar_from_file(mi->password, SCRAMBLED_PASSWORD_CHAR_LENGTH+1,
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init_intvar_from_file(&port, &mi->file, MYSQL_PORT) ||
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init_intvar_from_file(&connect_retry, &mi->file, DEFAULT_CONNECT_RETRY))
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If file has ssl part use it even if we have server without
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SSL support. But these option will be ignored later when
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slave will try connect to master, so in this case warning
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if (lines >= LINES_IN_MASTER_INFO_WITH_SSL)
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if (init_intvar_from_file(&ssl, &mi->file, 0) ||
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init_strvar_from_file(mi->ssl_ca, sizeof(mi->ssl_ca),
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init_strvar_from_file(mi->ssl_capath, sizeof(mi->ssl_capath),
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init_strvar_from_file(mi->ssl_cert, sizeof(mi->ssl_cert),
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init_strvar_from_file(mi->ssl_cipher, sizeof(mi->ssl_cipher),
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init_strvar_from_file(mi->ssl_key, sizeof(mi->ssl_key),
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Starting from 5.1.16 ssl_verify_server_cert might be
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if (lines >= LINE_FOR_MASTER_SSL_VERIFY_SERVER_CERT &&
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init_intvar_from_file(&ssl_verify_server_cert, &mi->file, 0))
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Starting from 6.0 master_heartbeat_period might be
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if (lines >= LINE_FOR_MASTER_HEARTBEAT_PERIOD &&
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init_floatvar_from_file(&master_heartbeat_period, &mi->file, 0.0))
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sql_print_warning("SSL information in the master info file "
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"('%s') are ignored because this MySQL slave was "
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"compiled without SSL support.", fname);
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This has to be handled here as init_intvar_from_file can't handle
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mi->master_log_pos= (my_off_t) master_log_pos;
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mi->port= (uint) port;
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mi->connect_retry= (uint) connect_retry;
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mi->ssl= (my_bool) ssl;
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mi->ssl_verify_server_cert= ssl_verify_server_cert;
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mi->heartbeat_period= master_heartbeat_period;
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DBUG_PRINT("master_info",("log_file_name: %s position: %ld",
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(ulong) mi->master_log_pos));
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if (init_relay_log_info(&mi->rli, slave_info_fname))
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// now change cache READ -> WRITE - must do this before flush_master_info
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reinit_io_cache(&mi->file, WRITE_CACHE, 0L, 0, 1);
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if ((error=test(flush_master_info(mi, 1))))
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sql_print_error("Failed to flush master info file");
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pthread_mutex_unlock(&mi->data_lock);
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sql_print_error("Error reading master configuration");
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my_close(fd, MYF(0));
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end_io_cache(&mi->file);
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pthread_mutex_unlock(&mi->data_lock);
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2 - flush relay log failed
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1 - flush master info failed
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int flush_master_info(Master_info* mi, bool flush_relay_log_cache)
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IO_CACHE* file = &mi->file;
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DBUG_ENTER("flush_master_info");
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DBUG_PRINT("enter",("master_pos: %ld", (long) mi->master_log_pos));
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Flush the relay log to disk. If we don't do it, then the relay log while
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have some part (its last kilobytes) in memory only, so if the slave server
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dies now, with, say, from master's position 100 to 150 in memory only (not
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on disk), and with position 150 in master.info, then when the slave
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restarts, the I/O thread will fetch binlogs from 150, so in the relay log
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we will have "[0, 100] U [150, infinity[" and nobody will notice it, so the
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SQL thread will jump from 100 to 150, and replication will silently break.
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When we come to this place in code, relay log may or not be initialized;
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the caller is responsible for setting 'flush_relay_log_cache' accordingly.
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if (flush_relay_log_cache &&
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flush_io_cache(mi->rli.relay_log.get_log_file()))
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We flushed the relay log BEFORE the master.info file, because if we crash
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now, we will get a duplicate event in the relay log at restart. If we
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flushed in the other order, we would get a hole in the relay log.
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And duplicate is better than hole (with a duplicate, in later versions we
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can add detection and scrap one event; with a hole there's nothing we can
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In certain cases this code may create master.info files that seems
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corrupted, because of extra lines filled with garbage in the end
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file (this happens if new contents take less space than previous
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contents of file). But because of number of lines in the first line
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of file we don't care about this garbage.
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char heartbeat_buf[sizeof(mi->heartbeat_period) * 4]; // buffer to suffice always
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my_sprintf(heartbeat_buf, (heartbeat_buf, "%.3f", mi->heartbeat_period));
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"%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%d\n%s\n",
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LINES_IN_MASTER_INFO,
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mi->master_log_name, llstr(mi->master_log_pos, lbuf),
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mi->password, mi->port, mi->connect_retry,
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(int)(mi->ssl), mi->ssl_ca, mi->ssl_capath, mi->ssl_cert,
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mi->ssl_cipher, mi->ssl_key, mi->ssl_verify_server_cert,
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DBUG_RETURN(-flush_io_cache(file));
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void end_master_info(Master_info* mi)
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DBUG_ENTER("end_master_info");
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end_relay_log_info(&mi->rli);
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end_io_cache(&mi->file);
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(void)my_close(mi->fd, MYF(MY_WME));
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#endif /* HAVE_REPLICATION */