Summary of online MYSQL synchronization error troubleshooting methods (must read)
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Preface After a failover occurs, a common problem is synchronization errors. When the database is small, it can be easily handled by dumping and then importing it. However, online databases are 150G-200G. If this method is used alone, the cost is too high. Therefore, after a period of exploration, several processing methods have been summarized. Production environment architecture diagram The current network architecture stores two copies of data and uses asynchronous replication to create a high-availability cluster, with two machines providing external services. When a failure occurs, switch to the slave and turn it into a master. The broken machine reversely synchronizes with the new master. When handling failures, the most common problem encountered is master-slave errors. The following is the error message I collected. Common Mistakes The three most common situations These three situations occur during HA switching. Due to asynchronous replication and sync_binlog=0, a small part of binlog will not be received, resulting in synchronization errors. The first one: a record is deleted on the master, but it cannot be found on the slave. Last_SQL_Error: Could not execute Delete_rows event on table hcy.t1; The second type: duplicate primary key. The record already exists on the slave, and the same record is inserted on the master. Last_SQL_Error: Could not execute Write_rows event on table hcy.t1; The third type: A record is updated on the master, but it cannot be found on the slave, resulting in data loss. Last_SQL_Error: Could not execute Update_rows event on table hcy.t1; Asynchronous semi-synchronous difference Asynchronous replication <br /> Simply put, the master sends the binlog, and the action ends regardless of whether the slave has received or executed it. Semi-synchronous replication <br /> Simply put, the master sends the binlog, and the slave confirms that it has received it. Regardless of whether it has been executed, the master sends a signal that it has received it, and the action is completed. (Code written by Google, officially applied in 5.5.) Disadvantages of asynchrony <br /> When the master is busy with write operations, the current POS point is, for example, 10, and the IO_THREAD thread on the slave receives 3. At this time, the master crashes, resulting in a difference of 7 points not being transmitted to the slave and data loss. Special circumstances The slave's relay log relay-bin is damaged. In this case, the SLAVE is down or shut down illegally, such as power failure, motherboard burnout, etc., causing the relay log to be damaged and synchronization to stop. Be careful of human errors: multiple slaves have duplicate server-ids Slave: received end packet from server, apparent master shutdown: Problem Solving Deletion failed Delete a record on the master, but it cannot be found on the slave. Last_SQL_Error: Could not execute Delete_rows event on table hcy.t1; Solution: Because the master wants to delete a record, but the slave cannot find it and reports an error, in this case, the master has deleted it, so the slave can skip it directly. Available commands: stop slave; If this happens frequently, you can use a script I wrote, skip_error_replcation.sh, which skips 10 errors by default (it only skips this situation, and outputs error results in other situations and waits for processing). This script is written in shell with reference to the mk-slave-restart principle of the maakit toolkit. It defines some of its own functions, and does not skip all errors. ） Duplicate primary key The record already exists on the slave, and the same record is inserted on the master. Last_SQL_Error: Could not execute Write_rows event on table hcy.t1; Duplicate entry '2' for key 'PRIMARY', Error_code: 1062; handler error HA_ERR_FOUND_DUPP_KEY; the event's master log mysql-bin.000006, end_log_pos 924 Solution: Use desc hcy.t1 on the slave; first look at the following table structure: mysql> desc hcy.t1; +-------+---------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+---------+------+-----+---------+-------+ | id | int(11) | NO | PRI | 0 | | | name | char(4) | YES | | NULL | | +-------+---------+------+-----+---------+-------+ Remove duplicate primary keys mysql> delete from t1 where id=2; Query OK, 1 row affected (0.00 sec) mysql> start slave; Query OK, 0 rows affected (0.00 sec) mysql> show slave status\G; … Slave_IO_Running: Yes Slave_SQL_Running: Yes … mysql> select * from t1 where id=2; Confirm again on the master and slave. Update lost A record is updated on the master, but it cannot be found on the slave, resulting in data loss. Last_SQL_Error: Could not execute Update_rows event on table hcy.t1; Can't find record in 't1', Error_code: 1032; handler error HA_ERR_KEY_NOT_FOUND; the event's master log mysql-bin.000010, end_log_pos 794 Solution: On the master, use mysqlbinlog to analyze what the wrong binlog log is doing. /usr/local/mysql/bin/mysqlbinlog --no-defaults -v -v --base64-output=DECODE-ROWS mysql-bin.000010 | grep -A '10' 794 #120302 12:08:36 server id 22 end_log_pos 794 Update_rows: table id 33 flags: STMT_END_F ### UPDATE hcy.t1 ###WHERE ### @1=2 /* INT meta=0 nullable=0 is_null=0 */ ### @2='bbc' /* STRING(4) meta=65028 nullable=1 is_null=0 */ ### SET ### @1=2 /* INT meta=0 nullable=0 is_null=0 */ ### @2='BTV' /* STRING(4) meta=65028 nullable=1 is_null=0 */ # at 794 #120302 12:08:36 server id 22 end_log_pos 821 Xid = 60 COMMIT /*!*/; DELIMITER ; # End of log file ROLLBACK /* added by mysqlbinlog */; /*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/; On the slave, find the updated record, which should not exist. mysql> select * from t1 where id=2; Then go to the master to check mysql> select * from t1 where id=2; +----+------+ | id | name | +----+------+ | 2 | BTV | +----+------+ 1 row in set (0.00 sec) Fill in the missing data on the slave and skip the error. mysql> insert into t1 values (2,'BTV'); Query OK, 1 row affected (0.00 sec) mysql> select * from t1 where id=2; +----+------+ | id | name | +----+------+ | 2 | BTV | +----+------+ 1 row in set (0.00 sec) mysql> stop slave ;set global sql_slave_skip_counter=1;start slave; Query OK, 0 rows affected (0.01 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) mysql> show slave status\G; … Slave_IO_Running: Yes Slave_SQL_Running: Yes … Relay log corruption The slave's relay log relay-bin is damaged. Last_SQL_Error: Error initializing relay log position: I/O error reading the header from the binary log Last_SQL_Error: Error initializing relay log position: Binlog has bad magic number; It's not a binary log file that can be used by this version of MySQL Manual repair Solution: Find the synchronized binlog and POS points, and then re-synchronize them so that you can have a new relay day value. example:
mysql> show slave status\G;
*************************** 1. row ***************************
Master_Log_File:mysql-bin.000010
Read_Master_Log_Pos: 1191
Relay_Log_File: vm02-relay-bin.000005
Relay_Log_Pos: 253
Relay_Master_Log_File: mysql-bin.000010
Slave_IO_Running: Yes
Slave_SQL_Running: No
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 1593
Last_Error: Error initializing relay log position: I/O error reading the header from the binary log
Skip_Counter: 1
Exec_Master_Log_Pos: 821
Slave_IO_Running: Receive binlog information from the master Master_Log_File Slave_SQL_Running: Execute write operation Relay_Master_Log_File The binlog and POS point of execution shall prevail.
Relay_Master_Log_File: mysql-bin.000010
Exec_Master_Log_Pos: 821
mysql> stop slave;
Query OK, 0 rows affected (0.01 sec)
mysql> CHANGE MASTER TO MASTER_LOG_FILE='mysql-bin.000010',MASTER_LOG_POS=821;
Query OK, 0 rows affected (0.01 sec)
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.8.22
Master_User: repl
Master_Port: 3306
Connect_Retry: 10
Master_Log_File:mysql-bin.000010
Read_Master_Log_Pos: 1191
Relay_Log_File: vm02-relay-bin.000002
Relay_Log_Pos: 623
Relay_Master_Log_File: mysql-bin.000010
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 1191
Relay_Log_Space: 778
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Ibbackup
All the tricks have been used, but the slave data has been lost too much. It's time for you to use ibbackup (which requires money). Ibbackup hot backup tool is paid. Xtrabackup is free and has the same functionality. Ibbackup does not lock the table during backup. A transaction is started during backup (equivalent to making a snapshot), and then a point is recorded. The subsequent data changes are saved in the ibbackup_logfile file. During recovery, the changed data in the ibbackup_logfile is written back to ibdata. Ibbackup only backs up data (ibdata, .ibd), and does not back up the table structure .frm. Here is a demonstration example: Backup: ibbackup /bak/etc/my_local.cnf /bak/etc/my_bak.cnf Restore: ibbackup --apply-log /bak/etc/my_bak.cnf [root@vm01 etc]# more my_local.cnf datadir = /usr/local/mysql/data innodb_data_home_dir = /usr/local/mysql/data innodb_data_file_path = ibdata1:10M:autoextend innodb_log_group_home_dir = /usr/local/mysql/data innodb_buffer_pool_size = 100M innodb_log_file_size = 5M innodb_log_files_in_group=2 [root@vm01 etc]# ibbackup /bak/etc/my_local.cnf /bak/etc/my_bak.cnf InnoDB Hot Backup version 3.0.0; Copyright 2002-2005 Innobase Oy License A21488 is granted to vm01 ([email protected]) (--apply-log works in any computer regardless of the hostname) Licensed for use in a computer whose hostname is 'vm01' Expires 2012-5-1 (year-month-day) at 00:00 See http://www.innodb.com for further information Type ibbackup --license for detailed license terms, --help for help Contents of /bak/etc/my_local.cnf: innodb_data_home_dir got value /usr/local/mysql/data innodb_data_file_path got value ibdata1:10M:autoextend datadir got value /usr/local/mysql/data innodb_log_group_home_dir got value /usr/local/mysql/data innodb_log_files_in_group got value 2 innodb_log_file_size got value 5242880 Contents of /bak/etc/my_bak.cnf: innodb_data_home_dir got value /bak/data innodb_data_file_path got value ibdata1:10M:autoextend datadir got value /bak/data innodb_log_group_home_dir got value /bak/data innodb_log_files_in_group got value 2 innodb_log_file_size got value 5242880 ibbackup: Found checkpoint at lsn 0 1636898 ibbackup: Starting log scan from lsn 0 1636864 120302 16:47:43 ibbackup: Copying log... 120302 16:47:43 ibbackup: Log copied, lsn 0 1636898 ibbackup: We wait 1 second before starting copying the data files... 120302 16:47:44 ibbackup: Copying /usr/local/mysql/data/ibdata1 ibbackup: A copied database page was modified at 0 1636898 ibbackup: Scanned log up to lsn 0 1636898 ibbackup: Was able to parse the log up to lsn 0 1636898 ibbackup: Maximum page number for a log record 0 120302 16:47:46 ibbackup: Full backup completed! [root@vm01 etc]# [root@vm01 etc]# cd /bak/data/ [root@vm01 data]# ls ibbackup_logfile ibdata1 [root@vm01 data]# ibbackup --apply-log /bak/etc/my_bak.cnf InnoDB Hot Backup version 3.0.0; Copyright 2002-2005 Innobase Oy License A21488 is granted to vm01 ([email protected]) (--apply-log works in any computer regardless of the hostname) Licensed for use in a computer whose hostname is 'vm01' Expires 2012-5-1 (year-month-day) at 00:00 See http://www.innodb.com for further information Type ibbackup --license for detailed license terms, --help for help Contents of /bak/etc/my_bak.cnf: innodb_data_home_dir got value /bak/data innodb_data_file_path got value ibdata1:10M:autoextend datadir got value /bak/data innodb_log_group_home_dir got value /bak/data innodb_log_files_in_group got value 2 innodb_log_file_size got value 5242880 120302 16:48:38 ibbackup: ibbackup_logfile's creation parameters: ibbackup: start lsn 0 1636864, end lsn 0 1636898, ibbackup: start checkpoint 0 1636898 ibbackup: start checkpoint 0 1636898 InnoDB: Doing recovery: scanned up to log sequence number 0 1636898 InnoDB: Starting an apply batch of log records to the database... InnoDB: Progress in percents: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 .....99 Setting log file size to 0 5242880 ibbackup: We were able to parse ibbackup_logfile up to ibbackup: lsn 0 1636898 ibbackup: Last MySQL binlog file position 0 1191, file name ./mysql-bin.000010 ibbackup: The first data file is '/bak/data/ibdata1' ibbackup: and the newly created log files are at '/bak/data/' 120302 16:48:38 ibbackup: Full backup prepared for recovery successfully! [root@vm01 data]# ls ibbackup_logfile ibdata1 ib_logfile0 ib_logfile1 Copy ibdata1 ib_logfile0 ib_logfile1 to the slave, and also copy .frm to it. After starting MySQL, synchronize it. That point is the output above: ibbackup: Last MySQL binlog file position 0 1191, file name ./mysql-bin.000010 Maatkit Toolkit Introduction MaatKit is an open source toolkit that provides assistance for daily management of MySQL. Currently, it has been acquired and maintained by Percona. in: mk-table-checksum is used to check whether the table structure and data on the master and slave are consistent. mk-table-sync is used to repair inconsistencies between master and slave data. There is no actual experience of operating these two toolkits in the live network. This is just a discussion of new technologies and academic exchanges. The following shows how to use them. http://www.actionsky.com/products/mysql-others/maatkit.jsp [root@vm02]# mk-table-checksum h=vm01,u=admin,p=123456 h=vm02,u=admin,p=123456 -d hcy -t t1 Cannot connect to MySQL because the Perl DBI module is not installed or not found. Run 'perl -MDBI' to see the directories that Perl searches for DBI. If DBI is not installed, try: Debian/Ubuntu apt-get install libdbi-perl RHEL/CentOS yum install perl-DBI OpenSolaris pgk install pkg:/SUNWpmdbi If it prompts that the perl-DBI module is missing, then directly yum install perl-DBI. [root@vm02 bin]# mk-table-checksum h=vm01,u=admin,p=123456 h=vm02,u=admin,p=123456 -d hcy -t t1 DATABASE TABLE CHUNK HOST ENGINE COUNT CHECKSUM TIME WAIT STAT LAG hcy t1 0 vm02 InnoDB NULL 1957752020 0 0 NULL NULL hcy t1 0 vm01 InnoDB NULL 1957752020 0 0 NULL NULL If the table data is inconsistent, the CHECKSUM value will be unequal. Explain what the output means: DATABASE: database name If you want to filter out which tables are not equal, you can use the tool mk-checksum-filter. Just add a pipe character at the end. [root@vm02 ~]# mk-table-checksum h=vm01,u=admin,p=123456 h=vm02,u=admin,p=123456 -d hcy | mk-checksum-filter hcy t2 0 vm01 InnoDB NULL 1957752020 0 0 NULL NULL hcy t2 0 vm02 InnoDB NULL 1068689114 0 0 NULL NULL Knowing which tables are inconsistent, you can use the mk-table-sync tool to handle them. Note: The table will be locked when executing mk-table-checksum. The size of the table depends on the speed of execution. Table t2 data on MASTER: Table t2 data on SLAVE:
mysql> select * from t2; mysql> select * from t2;
+----+------+ +----+------+
| id | name | | id | name |
+----+------+ +----+------+
| 1 | a | | 1 | a |
| 2 | b | | 2 | b |
| 3 | ss | | 3 | ss |
| 4 | asd | | 4 | asd |
| 5 | ss | +----+------+
+----+------+ 4 rows in set (0.00 sec)
5 rows in set (0.00 sec)
mysql> \!hostname;
mysql> \! hostname; vm02
vm01
[root@vm02 ~]# mk-table-sync --execute --print --no-check-slave --transaction --databases hcy h=vm01,u=admin,p=123456 h=vm02,u=admin,p=123456
INSERT INTO `hcy`.`t2`(`id`, `name`) VALUES ('5', 'ss') /*maatkit src_db:hcy src_tbl:t2 src_dsn:h=vm01,p=...,u=admin dst_db:hcy dst_tbl:t2
dst_dsn:h=vm02,p=...,u=admin lock:0 transaction:1 changing_src:0 replicate:0 bidirectional:0 pid:3246 user:root host:vm02*/;
Its working principle is: first check whether the tables of the master and slave libraries are the same row by row. If there are any differences, perform delete, update, insert and other operations to make them consistent. The size of the table determines how fast the execution will be. If C<--transaction> is specified, C<LOCK TABLES> is not used. Instead, lock and unlock are implemented by beginning and committing transactions. The exception is if L<"--lock"> is 3. If C<--no-transaction> is specified, then C<LOCK TABLES> is used for any value of L<"--lock">. See L<"--[no]transaction">. When enabled, either explicitly or implicitly, the transaction isolation level is set C<REPEATABLE READ> and transactions are started C<WITH CONSISTENT SNAPSHOT> MySQL replication monitoring Common MySQL error types 1005: Failed to create table Copy monitoring script Modified based on the original text. Original script
#!/bin/bash
#
#check_mysql_slave_replication_status
#
#
#
parasum=2
help_msg(){
cat <<
help
+---------------------+
+Error
Cause:
+you
must input $parasum parameters!
+1st
: Host_IP
+2st
: Host_Port
help
exit
}
[
$#
-ne ${parasum} ] && help_msg #If the parameters are not enough, print the help information and exit export HOST_IP=$1
export HOST_PORt=$2
MYUSER="root"
MYPASS="123456"
MYSQL_CMD="mysql
-u$MYUSER -p$MYPASS"
MailTitle="" #Mail subject Mail_Address_MysqlStatus="[email protected]" #Recipient mailbox time1=$(date +"%Y%m%d%H%M%S")
time2=$(date +"%Y-%m-%d
%H:%M:%S")
SlaveStatusFile=/tmp/salve_status_${HOST_PORT}.${time1}
#The file where the email content is located echo "--------------------Begin
at: "$time2
> $SlaveStatusFile
echo "" >>
$SlaveStatusFile
#get
slave status
${MYSQL_CMD}
-e "show
slave status\G" >>
$SlaveStatusFile #Get the status of the salve process#get
io_thread_status,sql_thread_status,last_errno Get the following status value IOStatus=$(cat $SlaveStatusFile|grep Slave_IO_Running|awk '{print
$2}')
SQLStatus=$(cat $SlaveStatusFile|grep Slave_SQL_Running
|awk '{print
$2}')
Errno=$(cat $SlaveStatusFile|grep Last_Errno
| awk '{print
$2}')
Behind=$(cat $SlaveStatusFile|grep Seconds_Behind_Master
| awk '{print
$2}')
echo "" >>
$SlaveStatusFile
if [
"$IOStatus" ==
"No" ]
|| [ "$SQLStatus" ==
"No" ]; then #Judge the error type if [
"$Errno" -eq 0
]; then #Maybe the salve thread is not started $MYSQL_CMD
-e "start
slave io_thread;start slave sql_thread;"
echo "Cause
slave threads does not run, trying to start slsave io_thread; start slave sql_thread;" >>
$SlaveStatusFile
MailTitle="[Warning]
Slave threads stopped on $HOST_IP $HOST_PORT"
elif [
"$Errno" -eq 1007
] || [ "$Errno" -eq 1053
] || [ "$Errno" -eq 1062
] || [ "$Errno" -eq 1213
] || [ "$Errno" -eq 1032
]\
||
[ "Errno" -eq 1158
] || [ "$Errno" -eq 1159
] || [ "$Errno" -eq 1008
]; then #Ignore these errors $MYSQL_CMD
-e "stop
slave;set global sql_slave_skip_counter=1;start slave;"
echo "Cause
slave replication catch errors,trying skip counter and restart slave;stop slave ;set global sql_slave_skip_counter=1;slave start;" >>
$SlaveStatusFile
MailTitle="[Warning]
Slave error on $HOST_IP $HOST_PORT! ErrNum: $Errno"
else
echo "Slave
$HOST_IP $HOST_PORT is down!" >>
$SlaveStatusFile
MailTitle="[ERROR]Slave
replication is down on $HOST_IP $HOST_PORT ! ErrNum:$Errno"
fi
fi
if [
-n "$Behind" ];then
Behind=0
fi
echo "$Behind" >>
$SlaveStatusFile
#delay
behind master determines the delay time if [
$Behind -gt 300 ];then
echo `date +"%Y-%m%d
%H:%M:%S"`
"slave
is behind master $Bebind seconds!" >>
$SlaveStatusFile
MailTitle="[Warning]Slave
delay $Behind seconds,from $HOST_IP $HOST_PORT"
fi
if [
-n "$MailTitle" ]; then #If an error occurs or the delay is greater than 300s, send an email cat ${SlaveStatusFile}
| /bin/mail -s
"$MailTitle" $Mail_Address_MysqlStatus
fi
#del
tmpfile:SlaveStatusFile
>
$SlaveStatusFileModified script Only simple tidying was done, and the judgment of Behind being NULL was corrected, but no test was done; Consider adding: Judgment on the results of repair execution; cyclic repair, detection, and repair of multiple errors? Cancel the SlaveStatusFile temporary file. The Errno and Behind alarms are sent to emails separately, and the alarm body is added with the original text of the show slave result. Increase PATH so that it can be added to crontab. Consider periodic execution in crontab (locking to avoid execution conflicts, execution cycle selection) Add execution log?
#!/bin/sh
#
check_mysql_slave_replication_status
#
Reference: http://www.tianfeiyu.com/?p=2062
Usage(){
echo Usage:
echo "$0
HOST PORT USER PASS"
}
[
-z "$1" -o
-z "$2" -o
-z "$3" -o
-z "$4" ]
&& Usage && exit 1
HOST=$1
PORT=$2
USER=$3
PASS=$4
MYSQL_CMD="mysql
-h$HOST -P$PORT -u$USER -p$PASS"
MailTitle="" #Mail subject Mail_Address_MysqlStatus="[email protected]" #Recipient mailbox time1=$(date +"%Y%m%d%H%M%S")
time2=$(date +"%Y-%m-%d
%H:%M:%S")
SlaveStatusFile=/tmp/salve_status_${HOST_PORT}.${time1}
#The file where the email content is located echo "--------------------Begin
at: "$time2
> $SlaveStatusFile
echo "" >>
$SlaveStatusFile
#get
slave status
${MYSQL_CMD}
-e "show
slave status\G" >>
$SlaveStatusFile #Get the status of the salve process#get
io_thread_status,sql_thread_status,last_errno Get the following status value IOStatus=$(cat $SlaveStatusFile|grep Slave_IO_Running|awk '{print
$2}')
SQLStatus=$(cat $SlaveStatusFile|grep Slave_SQL_Running
|awk '{print
$2}')
Errno=$(cat $SlaveStatusFile|grep Last_Errno
| awk '{print
$2}')
Behind=$(cat $SlaveStatusFile|grep Seconds_Behind_Master
| awk '{print
$2}')
echo "" >>
$SlaveStatusFile
if [
"$IOStatus" =
"No" -o
"$SQLStatus" =
"No" ]; then
case "$Errno" in
0)
#
It may be that the slave has not started $MYSQL_CMD
-e "start
slave io_thread;start slave sql_thread;"
echo "Cause
slave threads does not run, trying to start slsave io_thread; start slave sql_thread;" >>
$SlaveStatusFile
;;
1007|1053|1062|1213|1032|1158|1159|1008)
#
Ignore these errors $MYSQL_CMD
-e "stop
slave;set global sql_slave_skip_counter=1;start slave;"
echo "Cause
slave replication catch errors,trying skip counter and restart slave;stop slave ;set global sql_slave_skip_counter=1;slave start;" >>
$SlaveStatusFile
MailTitle="[Warning]
Slave error on $HOST:$PORT! ErrNum: $Errno"
;;
*)
echo "Slave
$HOST:$PORT is down!" >>
$SlaveStatusFile
MailTitle="[ERROR]Slave
replication is down on $HOST:$PORT! Errno:$Errno"
;;
esac
fi
if [
"$Behind" =
"NULL" -o
-z "$Behind" ];then
Behind=0
fi
echo "Behind:$Behind" >>
$SlaveStatusFile
#delay
behind master determines the delay time if [
$Behind -gt 300 ];then
echo `date +"%Y-%m%d
%H:%M:%S"`
"slave
is behind master $Bebind seconds!" >>
$SlaveStatusFile
MailTitle="[Warning]Slave
delay $Behind seconds,from $HOST $PORT"
fi
if [
-n "$MailTitle" ]; then #If an error occurs or the delay is greater than 300s, send an email cat ${SlaveStatusFile}
| /bin/mail -s
"$MailTitle" $Mail_Address_MysqlStatus
fi
#del
tmpfile:SlaveStatusFile
>
$SlaveStatusFileThe above summary of online MYSQL synchronization error troubleshooting methods (must-read) is all the content that the editor shares with you. I hope it can give you a reference, and I also hope that you will support 123WORDPRESS.COM. You may also be interested in:
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