Tag - Jay Janssen

High-load clusters and desynchronized nodes on Percona XtraDB Cluster

There can be a lot of confusion and lack of planning in Percona XtraDB Clusters in regards to nodes becoming desynchronized for various reasons.  This can happen a few ways:

An IST or SST joining node catching up after a state transfer (Joined/Joining state)
Using wsrep_desync for something like a backup
Executing a rolling-schema-upgrade using using wsrep_OSU_method=RSU

When […]

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Optimizing PXC Xtrabackup State Snapshot Transfer

State Snapshot Transfer (SST) at a glance
PXC uses a protocol called State Snapshot Transfer to provision a node joining an existing cluster with all the data it needs to synchronize.  This is analogous to cloning a slave in asynchronous replication:  you take a full backup of one node and copy it to the new […]

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PXC – Incremental State transfers in detail

IST Basics
State transfers in Galera remain a mystery to most people.  Incremental State transfers (as opposed to full State Snapshot transfers) are used under the following conditions:

The Joiner node reports Galera a valid Galera GTID to the cluster
The Donor node selected contains all the transactions the Joiner needs to catch up to the rest […]

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Bypassing SST in Percona XtraDB Cluster with binary logs

In my previous post, I used incremental backups in Percona XtraBackup as a method for rebuilding a Percona XtraDB Cluster (PXC) node without triggering an actual SST. Practically this reproduces the SST steps, but it can be handy if you already had backups available to use.
In this post, I want to present another methodology […]

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Bypassing SST in Percona XtraDB Cluster with incremental backups

Beware the SST
In Percona XtraDB Cluster (PXC) I often run across users who are fearful of SSTs on their clusters. I’ve always maintained that if you can’t cope with a SST, PXC may not be right for you, but that doesn’t change the fact that SSTs with multiple Terabytes of data can be quite […]

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