Performing backups to S3 with wsrep_desync

MySQL & MariaDB Percona XtraBackup
1

Dear Forum,

Is it true that xtrabackup does not set wsrep_desync=ON by itself and requires a wrapper script?
I have a 3-node cluster and have been using bgbackup (which is now archived) with great success. But now, that I want to try doing backups to S3 with xbcloud, I couldn’t figure out if xtrabackup desyncs the node before the process or not.

Can someone please advise?

2

xtrabackup does not desync the node because it is not necessary. Xtrabackup doesn’t require special locks (ie: FTWRL) that would prevent writes. xtrabackup is a hot-backup tool.

3

The problem is that xtrabackup might saturate my disks, while xbcloud might saturate my network, slowing down the whole cluster as a result.

It would be better to desync the node first, run the backups, wait until it catches up with the cluster and then sync it back with the cluster.

Looks like a wrapper is needed, oh well. Thank you for the info!

4

You can also control the resource consumption of xtrabackup with the –throttle option. For xbcloud the default is to run 1 concurrent thread only, so if you throttle xtrabackup which comes first in the pipe, the network consumption should be limited as well.