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This document describes the specific steps to stop and start the database and RabbitMQ in a HA environment.
For more details about restarting a Galera cluster, see https://galeracluster.com/library/training/tutorials/restarting-cluster.html

Check Galera cluster leader 

To stop or start the Galera cluster you should first identify the leader node.

  1. On the datanodes, check the state of Galera:

    Code Block
    [root@datanodes2 /]# cd /var/lib/mysql/
    [root@datanodes2 mysql]# cat grastate.dat 
    # GALERA saved state
    version: 2.1
    uuid:    c0e2c5f4-e045-11e9-988e-d6d16254ad99
    seqno:   -1
    safe_to_bootstrap: 0

    If there is a node with safe_to_bootstrap=1, you should start the cluster on this node
    If no node is marked as safe_to_bootstrap, force it (using the

...

  1. virtual IP).

...

Stop Galera cluster

To stop the Galera cluster do these steps.

  1. Find the leader node as described above

  2. Starting with the nodes that are not the leader. Stop the database on all nodes, .

    Code Block
    [root@datanodes2 /]# systemctl stop mariadb
    [root@datanodes1 /]# systemctl stop mariadb
    [root@datanodes0 /]# systemctl stop mariadb


...

Start Galera cluster

To start the Galera cluster, log in to the leader node.

  1. Start the cluster with this command

    Code Block
    [root@datanodes0 /]# galera_new_cluster

  2. On the other nodes, just start MariaDB or MySQL service

    Code Block
    [root@datanodes1 /]# systemctl start mariadb
    [root@datanodes2 /]# systemctl start mariadb

...

(tick) You can use these commands to check the cluster status:

Code Block
[root@datanodes1 mysql]# maxadmin show servers
[root@datanodes1 mysql]# maxadmin list servers

...


...

Check and rejoin RabbitMQ cluster

On each node datanode server do these commands.

Code Block
rabbitmqctl stop_app
rabbitmqctl join_cluster rabbit@datanodes1
rabbitmqctl join_cluster rabbit@datanodes2
rabbitmqctl start_app
rabbitmqctl cluster_status


...

Start services and servers

After you restart the Galera, MySQL and RabbitMQ on the datanode servers, do these steps

  1. On the services datanodes, manually start the Redis service

  2. Start the monitoring cluster (remember to wait 5 minutes for Cassandra, and 1 minute for KairosDB)

  3. Start other Abiquo servers (or restart tomcat services)