Configuration on FromDual GmbH

MaxScale configuration synchronisation

oli.sennhauser@fromdual.com (Oli Sennhauser) — Thu, 04 Apr 2024 09:53:46 +0000

Overview

A feature that I recently discovered while browsing is the MaxScale configuration synchronisation functionality.

MariaDB configuration analysis

oli.sennhauser@fromdual.com (Oli Sennhauser) — Tue, 30 Mar 2021 10:38:06 +0000

If we do customers database configuration analysis we check on one side if the most important MariaDB server system variables (innodb_buffer_pool_size, …) are set appropriately but also if some MariaDB server system variables are configured completely wrong.

MariaDB MaxScale Configuration Variables

oli.sennhauser@fromdual.com (Oli Sennhauser) — Wed, 04 Nov 2020 22:49:39 +0000

Global Options

Variable	Versions					Values	Default	Unit	Comment
threads	1.4		2.3	2.4	2.5	{ <n> \| auto }	1	thread
thread_stack_size		2.2				<n>			Ignored and deprecated in 2.3
rebalance_period					2.5	<n>	0	second
rebalance_threshold					2.5	<n>	20	delta load
rebalance_window					2.5	<n>	10	second
auth_connect_timeout	1.4	2.2	2.3	2.4		<n>	3	second
auth_read_timeout	1.4	2.2	2.3	2.4		<n>	1	second	Deprecated in 2.5
auth_write_timeout	1.4	2.2	2.3	2.4		<n>	2	second	Deprecated in 2.5
query_retries			2.3	2.4	2.5	<n>	1	time	Added in 2.1.10, disabled by default until 2.3.0
query_retry_timeout			2.3	2.4	2.5		5
passive			2.3	2.4	2.5		false
ms_timestamp	1.4		2.3	2.4	2.5	{ 0 \| 1 }	0	-
skip_permission_checks			2.3	2.4	2.5	{ 0 \| 1 }	0
syslog	1.4		2.3	2.4	2.5	{ 0 \| 1 }	1	-
maxlog	1.4		2.3	2.4	2.5	{ 0 \| 1 }	1	-
log_to_shm	1.4					{ 0 \| 1 }	0	-	Deprecated and ignored in 2.3.0 and newer
log_warning	1.4		2.3	2.4	2.5	{ 0 \| 1 }	1	-
log_notice	1.4		2.3	2.4	2.5	{ 0 \| 1 }	1	-
log_info	1.4		2.3	2.4	2.5	{ 0 \| 1 }	0	-
log_debug	1.4		2.3	2.4	2.5	{ 0 \| 1 }	0	-
log_warn_super_user					2.5		false
log_messages									Deprecated, use log_notice instead
log_trace									Deprecated, use log_info instead
log_augmentation	1.4		2.3	2.4	2.5	{ 0 \| 1 }	0	-
log_throttling			2.3	2.4	2.5	{ <n>, <n>, <n> }	10, 1000, 10000	time, millisecond, millisecond
logdir	1.4		2.3	2.4	2.5	<dirpath>	/tmp/	-
datadir	1.4		2.3	2.4	2.5	<dirpath>	/home/user/maxscale_data/	-
libdir	1.4		2.3	2.4	2.5	<dirpath>	/home/user/lib64/	-
cachedir	1.4		2.3	2.4	2.5	<dirpath>	/tmp/maxscale_cache/	-
piddir	1.4		2.3	2.4	2.5	<dirpath>	/tmp/maxscale_cache/	-
execdir	1.4		2.3	2.4	2.5	<dirpath>	/usr/local/bin/	-
connector_plugindir			2.3	2.4	2.5	<dirpath>	/usr/lib/plugin/
persistdir			2.3	2.4	2.5	<dirpath>	/var/lib/maxscale/maxscale.cnf.d/
module_configdir			2.3	2.4	2.5	<dirpath>	/var/lib/maxscale/
language	1.4		2.3	2.4	2.5	<dirpath>	/home/user/lang/	-
query_classifier			2.3	2.4	2.5	<classifier>	qc_sqlite
query_classifier_cache_size			2.3	2.4	2.5	<n>	15% of system Memory	byte
query_classifier_args			2.3	2.4	2.5
substitute_variables			2.3	2.4	2.5	{ true \| false }	false
sql_mode			2.3	2.4	2.5	{ default \| oracle }	default
local_address			2.3	2.4	2.5	<IP address>	*
users_refresh_time			2.3	2.4	2.5	<n>	30	second
user_refresh_interval				2.4	2.5	<n>	0	second
retain_last_statements			2.3	2.4	2.5	<n>	0	statement
dump_last_statements			2.3	2.4	2.5	{ on_error \| on_close \| never }	never	-
session_trace			2.3	2.4	2.5	<n>	0	statement
writeq_high_water			2.3	2.4	2.5
writeq_low_water			2.3	2.4	2.5
load_persisted_configs			2.3	2.4	2.5	{ 0 \| 1 }	1
max_auth_errors_until_block				2.4	2.5	<n>	10
debug					2.5
admin_host			2.3	2.4	2.5	<IP address>	127.0.0.1
admin_port			2.3	2.4	2.5	<n>	8989
admin_auth			2.3	2.4	2.5		1
admin_ssl_key			2.3	2.4	2.5
admin_ssl_cert			2.3	2.4	2.5
admin_ssl_ca_cert			2.3	2.4	2.5
admin_enabled			2.3	2.4	2.5	{ 0 \| 1 }
admin_gui					2.5		1
admin_secure_gui					2.5
admin_log_auth_failures				2.4	2.5	{ 0 \| 1 }	1
admin_pam_readwrite_service				2.4	2.5
admin_pam_readonly_service				2.4	2.5

Service Options

Variable	Versions					Values	Default	Unit	Comment
type	1.4		2.3	2.4	2.5	service		-
router	1.4		2.3	2.4	2.5	{ readconnroute \| readwritesplit \| schemarouter \| binlogrouter }		-
router_option	1.4		2.3	2.4	2.5	{ slave \| master,slave }		-
filters	1.4		2.3	2.4	2.5	{ counter \| QLA }		-
targets					2.5	{ server \| service, ... }
servers	1.4		2.3	2.4	2.5	{ <server1>, <server2>, ... }		-
cluster				2.4	2.5	<name>
user	1.4		2.3	2.4	2.5	{ <username> }		-
passwd	1.4		2.3	2.4	2.5	{ <password> }		-
enable_root_user	1.4		2.3	2.4	2.5	{ 0 \| 1 }	0	-
localhost_match_wildcard_host	1.4		2.3	2.4		{ 0 \| 1 }	0		Deprecated and ignored.
version_string	1.4		2.3	2.4	2.5	<string>	5.5.5-10.0.0 MaxScale <MaxScale version>
weightby	1.4		2.3	2.4		<server_weight>			Deprecated in 2.3 and removed in 2.5, use rank instead
auth_all_servers	1.4		2.3	2.4	2.5	{ 0 \| 1 }	0
strip_db_esc	1.4		2.3	2.4	2.5	{ 0 \| 1 }	0
optimize_wildcard	1.4			2.4		{ 0 \| 1 }	0
retry_on_failure	1.4		2.3			{ 0 \| 1 }	1		Ignored by 2.4 and removed in the future.
log_auth_warnings	1.4		2.3	2.4	2.5	{ 0 \| 1 }	0
connection_timeout	1.4		2.3	2.4	2.5	<n>		second
max_connections			2.3	2.4	2.5	<n>		connection
max_retry_interval		2.2	2.3	2.4		<n>	3600	second
session_track_trx_state			2.3	2.4	2.5		false		Only supported by MariaDB 10.3 and newer
retain_last_statements			2.3	2.4	2.5
connection_keepalive					2.5	<n>	300
net_write_timeout				2.4	2.5		0	second

Routing Modules

ReadConnRoute

For (weighted) load balancing.

Max_used_connections per user/account

oli.sennhauser@fromdual.com (Oli Sennhauser) — Thu, 30 Jul 2015 23:34:22 +0000

How many connections can be opened concurrently against my MySQL or MariaDB database can be configured and checked with the following command:

InnoDB Buffer Pool Instances is too small

oli.sennhauser@fromdual.com (Oli Sennhauser) — Thu, 16 Jul 2015 20:09:36 +0000

If you are using MariaDB/MySQL 5.5 and newer you should use several InnoDB Buffer Pool Instances for performance reasons.
Some rules to size InnoDB Buffer Pool instances are:

Binlog format MIXED with filtering

oli.sennhauser@fromdual.com (Oli Sennhauser) — Wed, 15 Jul 2015 06:11:36 +0000

Binlog format MIXED changes the binary log format (ROW or STATEMENT) depending on the queries (deterministic or not). This makes it impossible to define 100% correctly working binary log filter rules.

Flush time is set

oli.sennhauser@fromdual.com (Oli Sennhauser) — Wed, 15 Jul 2015 06:10:36 +0000

If the variable flush_time is set to a non-zero value, all tables are closed (and flushed) every flush_time seconds to disk. This can cause unnecessary and high I/O spikes.

Table definition cache too small

oli.sennhauser@fromdual.com (Oli Sennhauser) — Wed, 15 Jul 2015 06:08:36 +0000

The number of table definitions (SHOW CREATE TABLE<br>G) that can be stored in the table definition cache (table_definition_cache). If you have a large number of tables (
> 400) in your database instance, you should consider a larger table definition cache to increase your database throughput and decrease your query latency.
The command SELECT COUNT(*) FROM information_schema.tables; shows you how many tables and thus table definitions you have. The global status Open_table_definitions is the current amount of open table definitions.

Table open cache too small

oli.sennhauser@fromdual.com (Oli Sennhauser) — Wed, 15 Jul 2015 06:04:36 +0000

The Table Open Cache (table_open_cache or old name table_cache) is a cache to store file handles for all threads. The actual value of cache entries can be seen with the global status of open tables (Open_tables).
Increasing table_open_cache increases the number of file descriptors (open_files_limit) that MySQL requires.
You can check whether you need to increase the Table Open Cache by checking Open_tables and Opened_tables. If the value of Opened_tables is large and you do not use FLUSH TABLES often (which just forces all tables to be closed and reopened), then you should increase the value of the table_open_cache variable.

InnoDB Flush Method has changed

oli.sennhauser@fromdual.com (Oli Sennhauser) — Wed, 01 Jul 2015 10:34:36 +0000

The InnoDB Flush Method has changed. This can have an impact on InnoDB write Performance.

MySQL database configurator

oli.sennhauser@fromdual.com (Oli Sennhauser) — Sun, 23 Sep 2012 10:43:45 +0000

Will come soon…

Please let us know your intention to for choosing this page!

Configuration of MySQL for Shared Hosting

oli.sennhauser@fromdual.com (Oli Sennhauser) — Fri, 22 Apr 2011 13:03:31 +0000

If you ask around about shared hosting setups with MySQL everybody is frightened. In fact it looks like shared hosting is one of the most difficult setups you can get.

MySQL Cluster Local Checkpoint (LCP) and Global Checkpoint (GCP)

oli.sennhauser@fromdual.com (Oli Sennhauser) — Thu, 29 Jul 2010 16:29:48 +0000

MySQL Cluster is mainly an in-memory database. Nevertheless it requires a good I/O system for writing various different information to disk.

MySQL and MariaDB Configuration File template (my.cnf/my.ini)

oli.sennhauser@fromdual.com (Oli Sennhauser) — Mon, 15 Mar 2010 22:53:12 +0000

The MySQL and MariaDB default configuration is not very great for production use. Some of the default values in my.cnf should be changed when you need it for business critical applications.