The Replicator is a critical piece of the Tungsten Clustering solution for MySQL / MariaDB, as well as its own stand-alone data replication product. Automatic recovery is a feature that enables the Replicator to go back online in the event of a transient failure. In this blog we discuss how to enable Automatic Recovery. For more information about Auto-Recovery, please click here to visit the online documentation page.

The Question Recently, a customer asked us:

We see that the replicators receive a transaction which has a deadlock error in it:

pendingError : Event application failed: seqno=82880882 fragno=0 message=java.sql.SQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction

If one performs a service online, it comes back online without issue and continues …

In this blog post, we’ll look at how Percona XtraDB Cluster maintenance mode uses ProxySQL to take cluster nodes offline without impacting workloads.

Percona XtraDB Cluster Maintenance Mode

Since Percona XtraDB Cluster offers a high availability solution, it must consider a data flow where a cluster node gets taken down for maintenance (through isolation from a cluster or complete shutdown).

Percona XtraDB Cluster facilitated this by introducing a maintenance mode. Percona XtraDB Cluster maintenance mode reduces the number of abrupt workload failures if a node is taken down using ProxySQL (as a load balancer).

The central idea is delaying the core node action …