29.12.11.8 The replication_asynchronous_connection_failover Table

This table holds the replica's source lists for each replication channel for the asynchronous connection failover mechanism. The asynchronous connection failover mechanism automatically establishes an asynchronous (source to replica) replication connection to a new source from the appropriate list after the existing connection from the replica to its source fails. When asynchronous connection failover is enabled for a group of replicas managed by Group Replication, the source lists are broadcast to all group members when they join, and also when the lists change.

You set and manage source lists using the asynchronous_connection_failover_add_source and asynchronous_connection_failover_delete_source functions to add and remove replication source servers from the source list for a replication channel. To add and remove managed groups of servers, use the asynchronous_connection_failover_add_managed and asynchronous_connection_failover_delete_managed functions instead.

For more information, see Section 19.4.9, “Switching Sources and Replicas with Asynchronous Connection Failover”.

The replication_asynchronous_connection_failover table has these columns:

• CHANNEL_NAME

  The replication channel for which this replication source server is part of the source list. If this channel's connection to its current source fails, this replication source server is one of its potential new sources.

• HOST

  The host name for this replication source server.

• PORT

  The port number for this replication source server.

• NETWORK_NAMESPACE

  The network namespace for this replication source server. If this value is empty, connections use the default (global) namespace.

• WEIGHT

  The priority of this replication source server in the replication channel's source list. The weight is from 1 to 100, with 100 being the highest, and 50 being the default. When the asynchronous connection failover mechanism activates, the source with the highest weight setting among the alternative sources listed in the source list for the channel is chosen for the first connection attempt. If this attempt does not work, the replica tries with all the listed sources in descending order of weight, then starts again from the highest weighted source. If multiple sources have the same weight, the replica orders them randomly.

• MANAGED_NAME

  The identifier for the managed group that the server is a part of. For the GroupReplication managed service, the identifier is the value of the group_replication_group_name system variable.

The replication_asynchronous_connection_failover table has these indexes:

• Primary key on (CHANNEL_NAME, HOST, PORT, NETWORK_NAMESPACE, MANAGED_NAME)

TRUNCATE TABLE is not permitted for the replication_asynchronous_connection_failover table.