Start MySQL InnoDB Cluster from a complete outage

Introduction

Regardless of how MySQL InnoDB Cluster services were shut down (gracefully, hard shutdown, or power outage) a special startup procedure is required in order to put the cloud database back online.

Procedure

This example will assume that the state of the cloud database is as follows:

juju status mysql-innodb-cluster

App                   Version  Status   Scale  Charm                 Store       Channel  Rev  OS      Message
mysql-innodb-cluster  8.0.25   blocked      3  mysql-innodb-cluster  charmstore  stable     7  ubuntu  Cluster is inaccessible from this instance. Please check logs for details.

Unit                     Workload  Agent  Machine  Public address  Ports  Message
mysql-innodb-cluster/0   blocked   idle   0/lxd/2  10.0.0.240             Cluster is inaccessible from this instance. Please check logs for details.
mysql-innodb-cluster/1   blocked   idle   1/lxd/2  10.0.0.208             Cluster is inaccessible from this instance. Please check logs for details.
mysql-innodb-cluster/2*  blocked   idle   2/lxd/2  10.0.0.218             Cluster is inaccessible from this instance. Please check logs for details.

Initialise the cluster by running the reboot-cluster-from-complete-outage action on any mysql-innodb-cluster unit:

juju run-action --wait mysql-innodb-cluster/1 reboot-cluster-from-complete-outage

Important

If the chosen unit is not the most up-to-date in terms of cluster activity the action will fail. However, the action’s output messaging will include the correct node to use (in terms of its IP address). In such a case, simply re-run the action against the proper unit.

The mysql-innodb-cluster application should now be back to a clustered and healthy state:

App                   Version  Status  Scale  Charm                 Store       Channel  Rev  OS      Message
mysql-innodb-cluster  8.0.25   active      3  mysql-innodb-cluster  charmstore  stable     7  ubuntu  Unit is ready: Mode: R/O, Cluster is ONLINE and can tolerate up to ONE failure.

Unit                     Workload  Agent  Machine  Public address  Ports  Message
mysql-innodb-cluster/0   active    idle   0/lxd/2  10.0.0.240             Unit is ready: Mode: R/O, Cluster is ONLINE and can tolerate up to ONE failure.
mysql-innodb-cluster/1   active    idle   1/lxd/2  10.0.0.208             Unit is ready: Mode: R/O, Cluster is ONLINE and can tolerate up to ONE failure.
mysql-innodb-cluster/2*  active    idle   2/lxd/2  10.0.0.218             Unit is ready: Mode: R/W, Cluster is ONLINE and can tolerate up to ONE failure.

See the mysql-innodb-cluster section on the Managing power events page for full coverage.