From aadd6f38dcee3362417193ceeda0f540409dfa37 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Markus=20M=C3=A4kel=C3=A4?= Date: Fri, 9 Nov 2018 07:58:53 +0200 Subject: [PATCH] MXS-2153: Update available_when_donor documentation Added a more precise description of what the parameter does, what the accepted values are and where to get more information. --- Documentation/Monitors/Galera-Monitor.md | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/Documentation/Monitors/Galera-Monitor.md b/Documentation/Monitors/Galera-Monitor.md index c232a35c9..8bfb1632b 100644 --- a/Documentation/Monitors/Galera-Monitor.md +++ b/Documentation/Monitors/Galera-Monitor.md @@ -51,11 +51,20 @@ disable_master_failback=true ### `available_when_donor` -This option only has an effect if there is a single Galera node being backed up -an XtraBackup instance. This causes the initial node to go into Donor state -which would normally prevent if from being marked as a valid server inside -MaxScale. If this option is enabled, a single node in Donor state where the -method is XtraBackup will be kept in Synced state. +This option allows Galera nodes to be used normally when they are donors in an +SST operation when the SST method is non-blocking +(e.g. `wsrep_sst_method=mariabackup`). + +Normally when an SST is performed, both participating nodes lose their Synced, +Master or Slave statuses. When this option is enabled, the donor is treated as +if it was a normal member of the cluster (i.e. `wsrep_local_state = 4`). This is +especially useful if the cluster drops down to one node and an SST is required +to increase the cluster size. + +The current list of non-blocking SST +methods are `xtrabackup`, `xtrabackup-v2` and `mariabackup`. Read the +[wsrep_sst_method](https://mariadb.com/kb/en/library/galera-cluster-system-variables/#wsrep_sst_method) +documentation for more details. ``` available_when_donor=true