PerconaXtraDB Cluster 5.7.35 - 2 node (multi-master) + arbitrator node

Hello everyone!

  1. Is it necessary to use an arbiter node if 2 nodes in PXC (v.5.7.35) are using multi-master mode, and database entries are made to only one node via floating IP address? In such a case, can there be a split brain?

  2. Is there a way to configure master-slave mode instead of the default multi-master as I couldn’t find it anywhere?

Thanks in advance for your help!

Best regards,
Ivo P.

2 Likes

Hi @Ivo , thanks for posting to the Percona forums!

  1. The Galera Arbitrator is recommended for when you want to avoid deploying the 3rd PXC instance to save on costs, a the arbitrator only runs in memory (no copy of the data on disk is required). You should still consider deploying arbitrator when using a floating vip as it can then provide the assurance of no split brain - you could for example have a flapping VIP, or perhaps a user or application connects directly to the database.
  2. Youl’ll want to configure gcs.fc_single_primary=YES Galera Parameters — Galera Cluster Documentation
2 Likes

Hello @Michael_Coburn

thanks for help!

Best regards

1 Like