restoring a galera cluster from a backup

[ctc...@gmail.com]

Is there a standard procedure for restoring a 3 node galera cluster from a backup (created using innobackupex)?

[Philip Stoev]

Hello,

The most straightforward procedure would be as if starting a completely new
cluster:

1. Start mysqld with wsrep_provider not set in my.cnf
2. Restore data onto that server
3. Set wsrep_provider and the rest of the Galera options in my.cnf and then
bootstrap the node (e.g. by passing --wsrep-new-cluster to the init script)
4. Let the other nodes join the newly-formed cluster. This will happen via
SST

Philip Stoev

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[ctc...@gmail.com]

Hi Philip,

I am using galera 5.5.47 on CentOS 7, and I don't see a way to pass --wsrep-new-cluster to "systemctl start mysqld".

Also, this is a galera cluster as part of OpenStack, and the galera cluster is controlled by pacemaker using an OCF resource agent (in an HA Openstack setup based on quickstack / astapor from Redhat)

Chris

[hunter86bg]

Initial bootstrap is done via:

service mysql start --wsrep_new_cluster

or by creating a service file with a different name only for initial bootstrap (which is pointless).

[ctc...@gmail.com]

On my installation there is no mysql service, only mysqld, and I get:

# service mysqld start --wsrep_new_cluster
Redirecting to /bin/systemctl start  --wsrep_new_cluster mysqld.service
/bin/systemctl: unrecognized option '--wsrep_new_cluster'

[hunter86bg]

My version is for RHEL7 from codership's repository.

Are you using the mysql or the mariadb version ?

[hunter86bg]

Either try

service mysql start --wsrep-new-cluster

or

service mysql bootstrap

[ctc...@gmail.com]

We're using mariadb, and the rpms are galera-25.3.12-2.el7.x86_64 (from epel), mariadb-galera-common-5.5.40-3.el7.x86_64 and mariadb-galera-server-5.5.40-3.el7.x86_64 (from http://mirror.centos.org/centos/7/cloud/x86_64/openstack-liberty/common/)