Monit is easy to setup (a word away from the monster that is Nagios), and will save again and again.

http://stackoverflow.com/questions/325791/which-is-the-best-way-to-bi-directionally-synchronize-dynamic-data-in-real-time-u/325850#325850

on first server i have added these lines to mysqld section of my.cnf(mysql Ver 14.12 Distrib 5.0.77, for redhat-linux-gnu (i686) using readline 5.1)

datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock log-bin=/var/lib/mysql/mysql-bin.log binlog-do-db=sample1 binlog-ignore-db=mysql binlog-ignore-db=information_schema binlog-ignore-db=test2 binlog-ignore-db=sample3 binlog-ignore-db=example3 binlog-ignore-db=endpoints binlog-ignore-db=meetme binlog-ignore-db=test binlog-ignore-db=sample2

server-id=1 master-host = 192.xxx.x.xxx master-user = abc master-password = abc_pass master-connect-retry = 60

relay-log = /var/lib/mysql/slave-relay.log relay-log-index = /var/lib/mysql/slave-relay-log.index

On second server i have added these lines to mysqld section of my.cnf(mysql Ver 14.14 Distrib 5.1.41, for debian-linux-gnu (i486) using readline 6.1)

server-id=2

master-host = 192.xxx.x.xxx master-user = xyz master-password = xyz_pass master-connect-retry = 60

relay-log = /var/lib/mysql/slave-relay.log relay-log-index = /var/lib/mysql/slave-relay-log.index

log-bin = /var/lib/mysql/mysql-bin.log binlog-do-db = sample1 binlog-ignore-db=mysql binlog-ignore-db=information_schema binlog-ignore-db=phpmyadmin

on first server slave status is

*************************** 1. row *************************** Slave_IO_State: Connecting to master Master_Host: 192.xxx.x.xx Master_User: abc Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000001 Read_Master_Log_Pos: 36158 Relay_Log_File: slave-relay.000001 Relay_Log_Pos: 98 Relay_Master_Log_File: mysql-bin.000001 Slave_IO_Running: No 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: 36158 Relay_Log_Space: 98 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: NULL 1 row in set (0.00 sec)

ERROR: No query specified

On second server slave status is

*************************** 1. row *************************** Slave_IO_State: Connecting to master Master_Host: 192.xxx.x.xxx Master_User: xyz Master_Port: 3306 Connect_Retry: 60 Master_Log_File: Read_Master_Log_Pos: 4 Relay_Log_File: slave-relay.000003 Relay_Log_Pos: 4 Relay_Master_Log_File: Slave_IO_Running: No 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: 5 Exec_Master_Log_Pos: 0 Relay_Log_Space: 106 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: NULL Master_SSL_Verify_Server_Cert: No Last_IO_Errno: 1045 Last_IO_Error: error connecting to master ‘abc@192.xxx.x.xxx:3306′ – retry-time: 60 retries: 86400 Last_SQL_Errno: 0 Last_SQL_Error: 1 row in set (0.00 sec)

ERROR: No query specified

Do’nt know why Slave_IO_Running is no.

i have tried a lot to start replication but i am still unable to start replication. i have also commented

bind-address = 127.0.0.1

and

skip-external-locking

i need your help. Please send your suggestions and solution for this problem.

Thanks in advance.

regards, pradeep

To Nagios, I say only this: http://identi.ca/notice/10418281

Glad my blog entry helped. If you are currently using master-master replication, I really strongly urge you to stop. Switch to a single master and multiple slaves.

I found that if you are writing to both masters, with a decent amount of traffic, and have any unique indexes, you inevitably get conflict, which stops replication, and the data on the two servers gets rapidly inconsistent. It’s a nightmare to repair. I got it several times, faster and faster as traffic grew.

I searched and searched but could not find anyone out there using master-master replication and writing to both masters. Most people seem to use it as a hot standby. In fact most people seem to have one master, which takes the writes, and lots of slaves, which take the reads.

Regarding good monitoring, have you tried Nagios?