Merge "Try to reduce mysql memory usage"

.zuul.yaml

@@ -696,6 +696,9 @@
     description: |
       Simple multinode test to verify multinode functionality on devstack side.
       This is not meant to be used as a parent job.
+    vars:
+      devstack_localrc:
+        MYSQL_REDUCE_MEMORY: true
 
 # NOTE(ianw) Platform tests have traditionally been non-voting because
 # we often have to rush things through devstack to stabilise the gate,

lib/databases/mysql

@@ -176,6 +176,16 @@ function configure_database_mysql {
                 count INT, PRIMARY KEY (db, op)) ENGINE MEMORY" stats
     fi
 
+    if [[ "$MYSQL_REDUCE_MEMORY" == "True" ]]; then
+        iniset -sudo $my_conf mysqld read_buffer_size 64K
+        iniset -sudo $my_conf mysqld innodb_buffer_pool_size 16M
+        iniset -sudo $my_conf mysqld thread_stack 192K
+        iniset -sudo $my_conf mysqld thread_cache_size 8
+        iniset -sudo $my_conf mysqld tmp_table_size 8M
+        iniset -sudo $my_conf mysqld sort_buffer_size 8M
+        iniset -sudo $my_conf mysqld max_allowed_packet 8M
+    fi
+
     restart_service $MYSQL_SERVICE_NAME
 }
 

stackrc

@@ -201,6 +201,11 @@ DATABASE_QUERY_LOGGING=$(trueorfalse False DATABASE_QUERY_LOGGING)
 # performance_schema that are of interest to us
 MYSQL_GATHER_PERFORMANCE=$(trueorfalse True MYSQL_GATHER_PERFORMANCE)
 
+# This can be used to reduce the amount of memory mysqld uses while running.
+# These are unscientifically determined, and could reduce performance or
+# cause other issues.
+MYSQL_REDUCE_MEMORY=$(trueorfalse False MYSQL_REDUCE_MEMORY)
+
 # Set a timeout for git operations.  If git is still running when the
 # timeout expires, the command will be retried up to 3 times.  This is
 # in the format for timeout(1);