MySQL Router 8 fully supports MySQL 5.7 and MySQL 8, and it replaces the MySQL Router 2.x series. If you currently use Router 2.0 or 2.1 then we recommend upgrading your installation to MySQL Router 8.
The following conditions now cause disconnections: Connections to a primary after the primary is downgraded to a secondary, and connections to a node that are no longer part of the cluster.
Additionally, two new metadata-cache URI options were added: disconnect_on_promoted_to_primary controls whether existing client connections to a secondary are closed when the secondary is promoted as a primary (default=no), and disconnect_on_metadata_unavailable controls whether existing client connections are closed when the group is overloaded (default=no). See the
destinationsconfiguration option's documentation for additional information. (Bug #22817729, Bug #27148110, Bug #80491)
Added the optional
--account-hostcommand-line bootstrap option to configure the host pattern used for MySQL accounts. The default value is '%'.
Added the optional
--report-hostcommand-line bootstrap option to configure Router's externally visible hostname that's registered to the MySQL InnoDB cluster metadata store.
ttloption now accepts floating point values. The default ttl value changed from 5 seconds to 0.5 seconds (500 milliseconds), and the maximum allowed value changed from 4294967295 to 3600.
A mysql-server-mock tool was added to help make group replication testing more predictable. Execute mysql-server-mock --help for usage details.
An RPM package for installing ARM 64-bit (aarch64) binaries of MySQL Router on Oracle Linux 7 is now available in the MySQL Yum Repository and for direct download.
Known Limitation for this ARM release: You must enable the Oracle Linux 7 Software Collections Repository (ol7_software_collections) to install this package, and must also adjust the libstdc++7 path. See Yum's Platform Specific Notes for additional details.
If querying the metadata server failed, then the metadata refresh process would fail and log an error. Now the system will attempt to use alternative metadata servers instead of only one. (Bug #28082473)
When a primary or secondary node goes missing, the metadata cache refresh frequency increases to one second until the Group Replication status is confirmed. The log messages and code comments suggested that this mechanism only applies to missing primaries, so they were updated to clarify that missing secondaries also increase the frequency to one second. (Bug #28059228)
Exiting a running router instance by issuing Control + C emitted an exception before quitting the process. (Bug #27802114)
Support to compile with Visual Studio 15 2017 was added. (Bug #27691313)
thread_stack_sizeconfiguration option was added to define the allocated thread stack size for each thread. It is measured in kilobytes and defaults to 64 with a valid range of 1 to 65535. (Bug #27634367)
On Windows, PDB files were added to the Zip download for debugging purposes. (Bug #27531828, Bug #89625)