Is it possible to use different configurations on the servers of an xtradb cluster ?

Hi percona masters :slight_smile:

I’m currently updating the configuration of an XtraDB cluster, and I wonder if it is safe to use different values for the “innodb_buffer_pool_size” on different servers of the same XtraDb cluster?

My guess is that it has little to no impact on the global performance, but i’d wish to have confirmation on this point.

A little bit of context : I have a three-node XtraDb cluster, where each node is an identical machine with 32gb RAM. Two serveurs out of the three are dedicated to serve client requests, and they also run an Apache tomcat server. The third one is dedicated to creating hourly incremental enciphered backups with xtrabackup.

I’m considering to increase the “innodb_buffer_pool_size”, as its current value is innadequate (4Gb). I’d like to set its value to 20Gb (60% of the RAM) on the first and second server, and to something like 10Gb on the third server, as building backups is a ressource-intensive task in itself.



You should be able to run Percona XtraDB Cluster with different innodb_buffer_pool_size on different nodes.
Though keep in mind, that smaller innodb_buffer_pool_size may lead to worse performance, and overall cluster performance
is limited by its weakest node.

Thank you for your answer vadimtk.

It seems that it is reasonable to keep the same configuration on different nodes of the same cluster. That’s what we’ve eventually done, as xtraback running on our third node doesn’t eat much RAM !