Issues with MySql replication on MariaDB - mysql

I have been trying to get MySQL replication set up on digital ocean with forge servers & Maria DB.
I keep getting this error when running slave status\g :
Fatal error: 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).
This is the tutorial I followed:
https://www.digitalocean.com/community/tutorials/how-to-set-up-master-slave-replication-in-mysql
I've checked the server-id in both my.conf files and the master is set to 1 and the slave 2.
Here's a dump of the full status\g output
MariaDB [(none)]> SHOW SLAVE STATUS\G
*************************** 1. row ***************************
Slave_IO_State:
Master_Host: *****
Master_User: slave_user
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mariadb-bin.000017
Read_Master_Log_Pos: 642
Relay_Log_File: mysqld-relay-bin.000002
Relay_Log_Pos: 4 <br>
Relay_Master_Log_File: mariadb-bin.000017
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: 1
Exec_Master_Log_Pos: 642
Relay_Log_Space: 249
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: 1593
Last_IO_Error: Fatal error: 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).
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 1
Master_SSL_Crl:
Master_SSL_Crlpath:
Using_Gtid: No
Gtid_IO_Pos:
Replicate_Do_Domain_Ids:
Replicate_Ignore_Domain_Ids:
Parallel_Mode: conservative
Can anyone help?

Check that the config file is being used. It is probably /etc/my.cnf (not my.conf).
Run SHOW VARIABLES LIKE 'server_id'; on both servers.
Check that server_id is in the [mysqld] section of my.cnf.

Related

Strange slow performance in mysql replication

I have MySQL (MariaDB 10.1.27) master that hold ~1900 databases. Total dbs size ~100GB
Used InnoDB engine with innodb_file_per_table = 1
I'm going to setup two slaves for this server (MariaDB 10.1.27).
Both slaves with identical hardware like master.
master was stopeed at midnight, was made backup from /var/lib/mysql with tar
and this tar was transferred and extracted on two separated servers.
One slave setted up fast, and catched up master (1 day delay) in ~1 hour.
In time of catching up, I got 100% CPU usage (LA 3-4) with log of disk activity (~20%wa)
Second slave has some strange problem with replication performance.
After setup it catching up master more than 2 days. And procees finished 20% only.
current show slave status:
show slave status\Gshow processlist;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: XXXXXXXXXX
Master_User: XXXXXXXX
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysqld-bin.000572
Read_Master_Log_Pos: 524619108
Relay_Log_File: relay-bin.000004
Relay_Log_Pos: 916671538
Relay_Master_Log_File: mysqld-bin.000571
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: apsc.%,billing.%,information_schema.%,performance_schema.%,horde.%,mysql.%,phpmyadmin_gmRJC4rn_tom.%,psa.%,roundcubemail.%,sitebuilder5.%
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 916671245
Relay_Log_Space: 1598365917
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: 24730
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 111
Master_SSL_Crl:
Master_SSL_Crlpath:
Using_Gtid: No
Gtid_IO_Pos:
Replicate_Do_Domain_Ids:
Replicate_Ignore_Domain_Ids:
Parallel_Mode: conservative
1 row in set (0.00 sec)
No serious activity present on CPU and on disk (see top screen later)
======
top - 03:36:36 up 114 days, 12:26, 9 users, load average: 1.82, 1.86, 1.89
Tasks: 364 total, 1 running, 362 sleeping, 0 stopped, 1 zombie
Cpu(s): 1.5%us, 0.7%sy, 0.0%ni, 87.7%id, 4.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 32993560k total, 32271192k used, 722368k free, 625464k buffers
Swap: 4194296k total, 229512k used, 3964784k free, 23100280k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
13809 mysql 1 -19 6819m 5.8g 7332 S 8.9 18.5 132:12.33 mysqld
======
As I see, all bin logs transferred from master to slave currently,
but slave have slow performance in applying this logs to dbs.
In slow query log (2 seconds limit) I have no any records.
Googling problem not help. Already tried:
skip-name-resolve
innodb_flush_log_at_trx_commit=0
innodb-flush-method=O_DIRECT
#move innodb logs to SSD
nnodb_log_group_home_dir=/var/lib/mysql_logs
Setup multithreaded replication attempt (2 and 4 threads) was failed, because slowing down process more that current state. Slave got increasing lag (Seconds_Behind_Master in show slave status)
Please advice me what can be source of problem and what can be made to make replication faster.

Mysql master-slave replication breaks when issuing commands from master's phpmyadmin

I have successfully configured MYSQL slave from existing master SQL server using this https://www.digitalocean.com/community/tutorials/how-to-set-up-master-slave-replication-in-mysql
The setup works fine and changes made to master through MySQL shell are perfectly reflected on the slave. But if I issue commands from PHPMyAdmin, the system breaks down. it shows following error
mysql> show slave status \G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: ***.***.***.***
Master_User: *****
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.0000**
Read_Master_Log_Pos: 107
Relay_Log_File: mysql-relay-bin.00000*
Relay_Log_Pos: 2407
Relay_Master_Log_File: mysql-bin.000**
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: 1146
Last_Error: Error 'Table 'phpmyadmin.pma_table_uiprefs' doesn't exist' on query. Default database: ''. Query: 'REPLACE INTO `phpmyadmin`.`pma_table_uiprefs` VALUES ('**', '******', '******', '{"sorted_col":"`******`.`date` DESC","CREATE_TIME":"2016-12-19 09:35:35","col_order":["1","2","3","4","5","0","6","7","8","9"]}', NULL)'
Skip_Counter: 0
Exec_Master_Log_Pos: 2261
Relay_Log_Space: 8323
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: 0
Last_IO_Error:
Last_SQL_Errno: 1146
Last_SQL_Error: Error 'Table 'phpmyadmin.pma_table_uiprefs' doesn't exist' on query. Default database: ''. Query: 'REPLACE INTO `phpmyadmin`.`pma_table_uiprefs` VALUES ('******', '******', '******', '{"sorted_col":"`******`.`date` DESC","******":"2016-12-19 09:35:35","col_order":["1","2","3","4","5","0","6","7","8","9"]}', NULL)'
Replicate_Ignore_Server_Ids:
Master_Server_Id: 1
1 row in set (0.00 sec)
Phpmyadmin is not configured on the slave(I installed it without configuring it to slave parameters) and in the master configuration, I've explicitly set PHPmyadmin to not get replicated on slave through the following command.
binlog_ignore_db = phpmyadmin
How to remove this error
'phpmyadmin.pma_table_uiprefs' doesn't exist'
please guide.
The problem it's that the system it's trying to replicate the phpadmin tables that doesn't exist in your replica. To make it work, you need to exclude the phpmyadmin db.
In the slave mysqld.cnf file, you need to add this:
replicate-ignore-db=phpmyadmin
and restart the replica
So I have solved the issue by following steps
installing MySQL and PHPMyAdmin on slave through following guide http://usefulangle.com/post/35/how-to-install-linux-apache-mysql-php-phpmyadmin-lamp-stack-on-ubuntu-16-04
importing PHPMyAdmin tables from my master DB to slave DB. The problems were occurring due to the mismatch in table names in master and slave phpmyadmin tables.
What I've not understood is why slave was replicating PHPMyAdmin tables despite setting binlog_ignore_db = phpmyadmin in master configuration.

Mysql slave out of sync after crash

We have a "1 master, 1 slave" MySQL setup. We had a sudden power outage that took down the slave. After getting the machine back up, I found that the slave was out of sync with the master:
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 10.0.0.1
Master_User: slave
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-log.001576
Read_Master_Log_Pos: 412565824
Relay_Log_File: mysqld-relay-bin.002671
Relay_Log_Pos: 6930
Relay_Master_Log_File: mysql-log.001573
Slave_IO_Running: Yes
Slave_SQL_Running: No
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table: blah.table2
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 1032
Last_Error: Could not execute Update_rows event on table blah.info; Can't find record in 'info', Error_code: 1032; handler error HA_ERR_KEY_NOT_FOUND; the event's master log mysql-log.001573, end_log_pos 689031225
Skip_Counter: 0
Exec_Master_Log_Pos: 689030864
Relay_Log_Space: 2944772417
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: 0
Last_IO_Error:
Last_SQL_Errno: 1032
Last_SQL_Error: Could not execute Update_rows event on table blah.info; Can't find record in 'info', Error_code: 1032; handler error HA_ERR_KEY_NOT_FOUND; the event's master log mysql-log.001573, end_log_pos 689031225
Replicate_Ignore_Server_Ids:
Master_Server_Id: 1
1 row in set (0.00 sec)
We're using a binlog format of "ROW", so when I try to use mysqlbinlog to look at the offending row, I don't see anything of use. I don't want to simply set the skip counter, because I think that would throw my table even further out of sync.
Is there anything I can do on the slave that would essentially "roll back" to a given point in time, where I could then reset the master log number, poition, etc? If not, is there anything at all that I can do to get back in sync?
One can usually recover from small discrepancies using pt-table-checksum and pt-table-sync.
It looks to me like your slave lost its place in the binary log sequence when it crashes. The slave continually writes its last processed binlog event into datadir/relay-log.info, but this file uses buffered writes, so it is susceptible to losing data in a crash.
That's why Percona Server created a crash-resistant replication feature to store the same replica info in an InnoDB table, to recover from this scenario.
MySQL 5.6 has implemented a similar feature: you can set relay_log_info_repository=TABLE so the replica saves its state in a crash-resistant way.
Re your comment:
Yes, in theory pt-table-sync can fix any amount of replication drift, but it's not necessarily the most efficient way to correct large discrepancies. At some point, it's quicker and more efficient to trash the outdated replica and reinitialize it using a new backup from the master.
Check out How to setup a slave for replication in 6 simple steps with Percona Xtrabackup.

My MySQL Slave server has stopped replicating its' Master

I have a backup server that replicates my production server's mysql database, awhile ago I setup a staging server with the same php script with the only difference being that I gave it a read only mysql user so it can't make changes to the database, and only read from it. I'm not sure if it had anything to do with this but today I saw the backup had stopped working and it has the following error:
Got fatal error 1236 from master when reading data from binary log: 'Client requested master to start replication from impossible position'
Here is the output from the maser:
File: mysql-bin.000208
Position: 24383202
Binlog_Do_DB: sexxymofo
Binlog_Ignore_DB:
and the slave:
Slave_IO_State:
Master_Host: 184.168.76.5
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000193
Read_Master_Log_Pos: 54442531
Relay_Log_File: mysqld-relay-bin.000155
Relay_Log_Pos: 54442676
Relay_Master_Log_File: mysql-bin.000193
Slave_IO_Running: No
Slave_SQL_Running: Yes
Replicate_Do_DB: sexxymofo
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: 54442531
Relay_Log_Space: 54442875
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: 1236
Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'Client requested master to start replication from impossible position'
Last_SQL_Errno: 0
Last_SQL_Error:
as you can see the slave has got ahead of the master and into a non-existent position, can anyone help? I'm probably gonna restart the process but I would like to make sure it doesn't happen again.
Position is position within the file so the slave is way behind, on file mysql-bin.000193, and the master is already on mysql-bin.000208.
The impossible about this setup might be that the master has purged the file mysql-bin.000193 and since the slave isn't running IO that file hasn't been transferred.

Mysql Slave not updating

I have replication set up every thing looks fine I have not errors , but the data is not being moved to the Slave
mysql> show slave status \G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: xxxxx
Master_User: xxxxxx
Master_Port: xxxx
Connect_Retry: 30
Master_Log_File: mysql-bin.000006
Read_Master_Log_Pos: 98
Relay_Log_File: xxxxx-relay-bin.002649
Relay_Log_Pos: 235
Relay_Master_Log_File: mysql-bin.000006
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: 98
Relay_Log_Space: 235
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
1 row in set (0.00 sec)
Run a show master status or show master status\G on the master DB. It will give you the correct values to update your slave with.
From your slave status, it looks like your slave has successfully connected to the master and is awaiting log events. To me, this means your slave user has been properly set up, and has the correct access. It really seems like you just need to sync the correct log file position.
Careful, because to get a good sync, you should probably stop the master, dump the DB, record the master log file positions, then start the master, import the DB on the slave, and finally start the slave in slave mode using the correct master log file pos. I've done this about 30 times, and if you don't follow those steps almost exactly, you will get a bad sync.
there could be couple of issues
master did not know about slave.
slave and master are not in sync with relay log file.
you have to sync the slave with master from where it did not updated. then you start slave. it should work fine.