Release Notes for MariaDB MaxScale 2.5.21
MariaDB MaxScale is an advanced database proxy, firewall, and query router.
MariaDB MaxScale 2.5.21 was released on 2022-07-13. This release is of General Availability (GA) maturity.
Starting with this release, when the value of the
priorityparameter is negative, the Galera Monitor (
galeramon) will eliminate the node from the
Masterselection process. When the value is
0, the Galera Monitor (
galeramon) will still select the node as
Masterwhen no other nodes were available.
Can Result in Crashes, Hangs, Stalls
Can Result in Unexpected Behavior
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_sizeparameter, 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.
In earlier releases, when the
max_slave_replication_lagparameter 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_regexparameter, the cost of performing the duplicate table check grows very quickly as the number of tables increases. (MXS-4151)
connection_keepaliveparameter 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 TOstatement
CHANGE MASTER TOstatement 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.
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
router_options=masteris set, Read Connection Router (
readconnroute) chooses the second server, because the rank of the first server is ignored.
Starting with this release, Schema Router (
schemarouter) will automatically ignore the
sysschema for duplicate checks.
Install and Upgrade
When the MaxScale package is installed, the
/etc/maxscale.cnf.d/directory is not automatically created. (MXS-4134)
In alignment to the MariaDB Corporation Engineering Policy, MariaDB MaxScale 2.5.21 is provided for:
CentOS 7 (x86_
Debian 9 (x86_
Debian 10 (x86_
Debian 11 (x86_
Red Hat Enterprise Linux 7 (x86_
Red Hat Enterprise Linux 8 (x86_
Rocky Linux 8 (x86_
SUSE Linux Enterprise Server 15 (x86_
Ubuntu 18.04 (x86_
Ubuntu 20.04 (x86_