From 6534413cf3940c6f2c7585cc66d4febe7d65b575 Mon Sep 17 00:00:00 2001
From: Evangelos Foutras <evangelos@foutrelis.com>
Date: Wed, 18 Aug 2021 19:56:50 +0300
Subject: [PATCH] mariadb: Tweak query cache settings
We used to set query_cache_type to 0 in the default settings but we were
also setting query_cache_size to a non-zero/non-default value, which was
in turn re-enabling the query cache. Update the configuration to reflect
the actual cache state and make sure query_cache_size is set to zero for
the "query_cache_type = 0" case.
Now that the setting controls the real state of the query cache, disable
it for bbs.archlinux.org; its hit rate is small compared to insert rate.
---
playbooks/bbs.archlinux.org.yml | 2 +-
roles/mariadb/defaults/main.yml | 2 +-
roles/mariadb/templates/server.cnf.j2 | 12 +++++++++---
3 files changed, 11 insertions(+), 5 deletions(-)
diff --git a/playbooks/bbs.archlinux.org.yml b/playbooks/bbs.archlinux.org.yml
index c345169e0..a3a24a95c 100644
--- a/playbooks/bbs.archlinux.org.yml
+++ b/playbooks/bbs.archlinux.org.yml
@@ -10,7 +10,7 @@
- { role: root_ssh }
- { role: certbot }
- { role: nginx }
- - { role: mariadb }
+ - { role: mariadb, mariadb_query_cache_type: '0' }
- { role: sudo }
- { role: php_fpm, php_extensions: ['apcu', 'iconv', 'intl', 'mysqli'], zend_extensions: ['opcache'] }
- { role: fluxbb }
diff --git a/roles/mariadb/defaults/main.yml b/roles/mariadb/defaults/main.yml
index 2568778d9..d21707802 100644
--- a/roles/mariadb/defaults/main.yml
+++ b/roles/mariadb/defaults/main.yml
@@ -9,7 +9,7 @@ mariadb_net_buffer_length: '8K'
mariadb_read_buffer_size: '256K'
mariadb_read_rnd_buffer_size: '512K'
mariadb_myisam_sort_buffer_size: '8M'
-mariadb_query_cache_type: '0'
+mariadb_query_cache_type: '1'
mariadb_query_cache_limit: '16M'
mariadb_query_cache_size: '32M'
mariadb_max_connections: '400'
diff --git a/roles/mariadb/templates/server.cnf.j2 b/roles/mariadb/templates/server.cnf.j2
index e2c71188c..1d5bf186e 100644
--- a/roles/mariadb/templates/server.cnf.j2
+++ b/roles/mariadb/templates/server.cnf.j2
@@ -23,13 +23,19 @@ net_buffer_length = {{ mariadb_net_buffer_length }}
read_buffer_size = {{ mariadb_read_buffer_size }}
read_rnd_buffer_size = {{ mariadb_read_rnd_buffer_size }}
myisam_sort_buffer_size = {{ mariadb_myisam_sort_buffer_size }}
-query_cache_type = {{ mariadb_query_cache_type }}
-query_cache_limit = {{ mariadb_query_cache_limit }}
-query_cache_size = {{ mariadb_query_cache_size }}
max_connections = {{ mariadb_max_connections }}
thread_cache_size = {{ mariadb_thread_cache_size }}
userstat = 1
+# Query cache settings
+query_cache_type = {{ mariadb_query_cache_type }}
+query_cache_limit = {{ mariadb_query_cache_limit }}
+{% if mariadb_query_cache_type == '0' %}
+query_cache_size = 0
+{% else %}
+query_cache_size = {{ mariadb_query_cache_size }}
+{% endif %}
+
# Single server setup
server-id = 1
--
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