I have setup MySQL replication with Percona 5.5.25a server as a slave for MySQL 5.0.95 master. Slave is very slow in catching up with master. It is lagging behind master for around 2 days now. Both the master and slave runs on VM nodes. Physical configuration of both the nodes are same. MySQL configuration is also same on both.
When I change the slave to 5.0.95, slave immediately catches up and never lags behind master.
I am using Innodb as the engine. Innodb status on the slave showed that there were locks on a table during replication. Every time an update runs on this table, the locks were held for around 15 to 20 mins. I have ignored this table in replication. After this, there are no locks observed in the slave. But the QPS on slave is only 4. With this rate, the slave is never to going to catch up with the master.
Any suggestions on how to resolve this will be much appreciated.