Release Notes for MariaDB MaxScale 2.5.21

When Binlog Router (binlogrouter) is used, a race condition can cause MaxScale to crash. (MXS-4138)

When the connection_keepalive parameter is 0, a memory leak can cause MaxScale to crash. (MXS-4100, MXS-4141)

When Avrorouter replicates binary log events that reference sequencessequences, MaxScale can crash. (MXS-4120)

When Schema Router (schemarouter) is used, the sys schema is not automatically ignored for duplicate checks. (MXS-4110)

• In earlier releases, the ignore_tables_regex parameter would have to be used to configure Schema Router (schemarouter) to ignore the sys schema when used with MariaDB Enterprise Server 10.6.

• Starting with this release, Schema Router (schemarouter) will automatically ignore the sys schema for duplicate checks.

When the same query is executed multiple times, the size of the query classifier cache could incorrectly increase, even though the query was only cached once. (MXS-4194)

• In earlier releases, repeatedly executing a query could cause the size of the query classifier cache to surpass the value of the query_classifier_cache_size parameter, which would cause the query classifier cache to be disabled.

• Starting with this release, the size of the query classifier cache is updated correctly when the same query is executed multiple times.

When TLS is enabled, MaxScale tries to generate 512-bit RSA keys, which are disabled when OpenSSL is running in FIPS mode. (MXS-4181)

• In earlier releases, when this issue occurred on a system using OpenSSL 1.0.1 (such as some older CentOS 7 and RHEL 7 releases), the following error messages would be written to the MaxScale log:

  error  : (SERVER_NAME); 512-bit RSA key generation failed.
  error  : (SERVER_NAME); Unable to initialize SSL for server 'SERVER_NAME'
  error  : Failed to create a new server.
  

When maxctrl show filters is executed, the output does not contain filter diagnostics. (MXS-4166)

When the Cat Router (cat) is used, sessions are not always closed, which can trigger a debug assertion to fail. (MXS-4164)

The max_slave_replication_lag parameter could not be set to a non-zero value with Galera Monitor (galeramon). (MXS-4160)

• In earlier releases, when the max_slave_replication_lag parameter was set to a non-zero value with Galera Monitor (galeramon), the following error message would be written to the MaxScale log when Read/Write Split Router (readwritesplit) tried to route a query to a replica node:

  Could not find valid server for target type TARGET_SLAVE (COM_QUERY: QUERY_TEXT), closing connection.
  

When Schema Router (schemarouter) is used and duplicate table checks are not disabled with the ignore_tables_regex parameter, the cost of performing the duplicate table check grows very quickly as the number of tables increases. (MXS-4151)

When Schema Router (schemarouter) is used, query routing performance scales poorly as the number of tables increases. (MXS-4152)

When the connection_keepalive parameter is non-zero, MaxScale sends pings to servers even if the client is idle. (MXS-4139)

When MariaDB Monitor (mariadbmon) performs failover, MaxScale writes a CHANGE MASTER TO statementCHANGE MASTER TO statement containing the replication user's user name and password in plain text to the MaxScale Log. (MXS-4115)

• Starting with this release, the user name and password are masked in the statement written to the MaxScale Log.

When multiple servers are selected as Master with Read Connection Router (readconnroute), the rank parameter is ignored for all servers except the last one. (MXS-4132)

• In earlier releases, this could impact query routing in some configurations. For example, let's say that two servers are selected as Master: the first has rank=primary, and the second has rank=secondary. When router_options=master is set, Read Connection Router (readconnroute) chooses the second server, because the rank of the first server is ignored.

When a service uses the targets parameter to route queries to a second service, the second service is not shown as a target in the output of maxctrl list services. (MXS-4127)

If the value of the query_classifier_cache_size parameter is set high, executing maxctrl show qc_cache can cause MaxCtrl to run out of memory. (MXS-4121)

When the MaxScale package is installed, the /etc/maxscale.cnf.d/ directory is not automatically created. (MXS-4134)