# MySQL Enterprise to Percona Upgrade

**URL:** <https://forums.percona.com/t/mysql-enterprise-to-percona-upgrade/3852>\
**Category:** Other MySQL® Questions\
**Created:** [November 4, 2014, 10:37am UTC](https://forums.percona.com/t/mysql-enterprise-to-percona-upgrade/3852 "2014-11-04T10:37:32Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![dbasaurus](https://avatars.discourse-cdn.com/v4/letter/d/0ea827/32.png) [@dbasaurus](https://forums.percona.com/u/dbasaurus)\
**Post date:** [November 4, 2014, 10:37am UTC](https://forums.percona.com/t/mysql-enterprise-to-percona-upgrade/3852/1 "2014-11-04T10:37:32Z")

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Recently, I upgraded an instance of MySQL Enterprise 5.1 to Percona Server 5.5 and am now having issues with getting the slave to stay in sync. In addition, the seconds behind master field from the show slave status statement is behaving oddly. It fluctuates from 0 to, for example, 20,000 seconds. Here is an example:

slave-server : 09:16:30 : ~

# mysql -e “SHOW SLAVE STATUS\G” | grep Seconds\_Behind\_Master;sleep 5;mysql -e “SHOW SLAVE STATUS\G” | grep Seconds\_Behind\_Master

Seconds\_Behind\_Master: 0  
Seconds\_Behind\_Master: 4577

The whole lag is a bit odd,because the slave kept up fine when it was on MySQL 5.1 Enterprise. If you shutdown the server down for a few minutes it would take some time to catch back up cause the hardware is different between the two servers, but not this bad. Thus, I am wondering if I am missing a setting or something. Current settings:

max-allowed-packet = 16M  
max-connect-errors = 1000000  
back\_log = 4096  
interactive\_timeout = 600  
wait\_timeout = 600  
tmp-table-size = 128M  
max-heap-table-size = 128M  
query-cache-type = 1  
query-cache-size = 64M  
max-connections = 100  
thread-cache-size = 10  
open-files-limit = 65535  
table-definition-cache = 4096  
table-open-cache = 4096  
key-buffer-size = 384M  
myisam-recover-options = FORCE,BACKUP  
innodb-flush-method = O\_DIRECT  
innodb-log-files-in-group = 2  
innodb-log-file-size = 1G  
innodb\_log\_buffer\_size = 16M  
innodb-flush-log-at-trx-commit = 2  
innodb-file-per-table = 1  
innodb-buffer-pool-size = 100G  
innodb\_buffer\_pool\_instances = 5  
innodb\_read\_io\_threads = 8  
innodb\_write\_io\_threads = 8  
innodb\_io\_capacity = 400  
read-only = 1  
skip-slave-start = 1  
relay-log-purge = 1  
slave-net-timeout = 60  
sync-master-info = 1  
sync-relay-log = 1  
sync-relay-log-info = 1  
slave\_compressed\_protocol = 1

NOTE: The master server is still on MySQL Enterprise 5.1.

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**Author:** ![niljoshi](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/niljoshi/32/16889_2.png) [@niljoshi](https://forums.percona.com/u/niljoshi)\
**Post date:** [November 13, 2014, 3:36am UTC](https://forums.percona.com/t/mysql-enterprise-to-percona-upgrade/3852/2 "2014-11-13T03:36:33Z")

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Hi,

There are huge difference in 5.1 and 5.5. I hope you have checked this link before upgrade the slave.  
[url][Percona Server for MySQL 8.0 - Documentation — Percona Server 8.0 Documentation](http://www.percona.com/doc/percona-server/5.5/upgrading_guide_51_55.html%5B/url%5D)

There might be any reasons behind the slave lag. You must need to find the reason of slave lag. This post might help to you.  
[url][http://www.percona.com/blog/2014/05/02/how-to-identify-and-cure-mysql-replication-slave-lag/[/url]](http://www.percona.com/blog/2014/05/02/how-to-identify-and-cure-mysql-replication-slave-lag/%5B/url%5D)

Also, on which specific version of 5.5, you have migrated? there might be some bugs related to that.