Enabling or Disabling High Availability
Enabling high availability converts a standalone DB system to a high availability DB system and disabling high availability converts a high availability DB system to a standalone DB system.
- Enabling high availability on a standalone DB system creates a highly available DB system using the existing MySQL instance as the primary instance, creating two more secondary instances, and replicating the data present in the primary instance to the secondary instances. No downtime occurs.
- Disabling high availability on a DB system creates a standalone DB system from the instance running in the preferred primary placement.
- If the primary instance is running in the preferred primary placement, no downtime occurs.
- If the primary instance is not running in the preferred primary placement, a failover occurs and this causes a short downtime.
Using the Console
Use the Console to enable or disable high availability on a standalone DB system.
This task requires the following:
- A running standalone DB system.
- Primary keys exist on every table in the database. See Prerequisites.
- Any active inbound replication channel on the DB system must be stopped for the duration of this task. See Enabling or Disabling a Channel. You cannot enable high availability while an active channel is connected to the DB system. This is required only if the configuration used by the DB system is not compatible with high availability. If the DB system is using a compatible configuration, it is not necessary to stop the inbound replication channel to enable high availaibility. Changing the configuration of a DB system requires a restart of the DB system.
- Crash recovery is enabled. You cannot enable high availability on a DB system if crash recovery is disabled. See Crash Recovery.
- MySQL version must be 8.0.24 or higher. You cannot enable high availability on earlier versions of MySQL. If the DB system uses a version older than 8.0.24, you must upgrade before enabling high availability.
- If you intend to configure an inbound replication channel on this DB system, you must import data before enabling high availability, and configure your channel after high availability is enabled.
Note
If you encounter
If you encounter
OutOfHostCapacity
work request
error while enabling high availability in a DB system, see
Resolving OutOfHostCapacity Error.
Note
If a HeatWave cluster load or reload operation is going on, enabling or disabling high availability can fail. It is recommended to not enable or disable high availability while a HeatWave cluster load or reload operation is going on.
If a HeatWave cluster load or reload operation is going on, enabling or disabling high availability can fail. It is recommended to not enable or disable high availability while a HeatWave cluster load or reload operation is going on.
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