Changes in MySQL Router 8.0.31 (2022-10-11, General Availability)

• Functionality Added or Changed

• Bugs Fixed

Functionality Added or Changed

• You can now configure MySQL Router to write a core file in the event the MySQL Router process fails. See Configuration File Options for information on the --core-file. option. (WL #15185)

• MySQL Router periodically updates the last_check_in of the Cluster metadata schema. Under certain circumstances, such as a ClusterSet split-brain scenario, these updates can make rejoin operations impossible due to the creation of errant transactions.

  As of this release, MySQL Router checks the value of a new Metadata schema option, stats_updates_frequency, in the JSON field v2_cs_router_options.router_options, and updates the check-in behaviour based on the value of this option.

  If the target Cluster is a member of a ClusterSet, MySQL Router does the following:

  • MySQL Router always updates last_check_in when it starts.

  • If the value of stats_updates_frequency is a positive integer N, MySQL Router continues updating last_check_in every N seconds.

  • If the value of stats_updates_frequency is zero or missing entirely, MySQL Router does not update last_check_in.The same is true if the value of stats_updates_frequency is not a valid positive integer.

  If the target Cluster is not a member of a ClusterSet, MySQL Router's behavior is unchanged. last_check_in is updated every tenth refresh cycle. This cycle is not configurable.

  stats_updates_frequency can be updated using the MySQL Shell command, clusterSet.setRoutingOption(). See MySQL Router Status for InnoDB ClusterSet. (WL #15230)

Bugs Fixed

• Connections which were closed by the server were maintained in the connection pool, resulting in an error if the connection was reused. (Bug #34536576)

• MySQL Router rejected compressed connections with the error error:5000, bad message.

  MySQL Router does not currently support compressed connections. As of this release, if a client requests a compressed connection, MySQL Router replies that it does not support them. The client can then use an uncompressed connection. (Bug #34445287)

• Under certain circumstances, the unreachable destination quarantine mechanism, introduced in MySQL Router 8.0.29, could block new, valid connections for the duration of unreachable_destination_refresh_interval, while there is a quarantined, unavailable destination. (Bug #34427559)

• Some configuration options were not correctly validated by the configuration checker. For example, bootstrapping with --name resulted in an error although it is a valid configuration option. (Bug #34258782)

• Multiple errors were logged if a client application did not send, or did not support, connection attributes. (Bug #34196750)

• Processing SQL statements of 16MB or larger caused MySQL Router to become unresponsive. (Bug #107982, Bug #34426322)

• MySQL Router stopped responding when calling a stored procedure with a prepared statement. (Bug #107951, Bug #34420764)