I have 3 nodes PXC 5.6 cluster. Xtrabackup 2.3.10. Centos 7.6
Percona-XtraDB-Cluster-56-5.6.41-28.28.1.el7.x86_64
I am using only single Node-1 for both read and write.
And I use to take backup from another Node-2 which is not used for read or write.
Yesterday, my Node-1 went down and read/write switched to Node-2. Then we continued to take incremental backup from another unused Node-3.
On my backup machine, I decided to extract and prepare backup. My backup preparation log shows everything fine until those backups that were taken from Node-2. All the incremental backups from Node-3 had errors.
Why does it seems like incremental backup should always be from the same node where the full backup was taken? Percona XtraDB Cluster is master-master and so all nodes must be same. Then why did this happen?
I have attached my logs here:
Best Answer
LSN (Log Sequence Number), which incremental backup is based on, is specific to an instance. That's why knowing full copy LSN means nothing on other node.