Bug#20956599 CAN'T SET PERFORMANCE_SCHEMA=OFF IN 5.7

Before this fix,

For a server compiled with performance schema support,
when starting the server with the performance schema
disabled at startup time, as in:
  performance_schema = OFF

the server would fail to create performance_schema tables,
which in turn causes the creation of views provided by sysschema to fail.

The root cause is as follows:
- during the server startup, the code detects that
  the performance schema is not initialized.
- the variable load_perfschema_engine stays as false as a result
- later, when loading the performance schema plugin,
  the plugin is loaded with the option PLUGIN_OFF (aka, not loaded)
- during the database initialization in mysql_system_tables.sql,
  the scripts looks for entries in table information_schema.engines,
  and finds none, leading the script to assume the server is not compiled
  with performance schema support.
- performance schema tables are not created during the install.
- installation of the sysschema views fail.

The fix is to simplify and streamline the entire process,
which is too convoluted.

In particular,

- a server compiled with performance schema support always
  load the performance schema engine, now mandatory,
  regardless of the runtime configuration.

- a server compiled with performance schema support always
  create the performance schema tables during install.

The database layout of the installed product should depend only on build options
(to compile with of without the performance schema),
and never depend on runtime configurations options
(to start the server with or without instrumentation)

When the performance schema is not used during server startup,
no data will be collected and no memory allocated,
so there is no performance impact: there are no changes here.

The only change is to always create performance schema tables
when the server is compiled with performance schema support.

Author: marcalff

mysql-test/include/have_perfschema.inc

@@ -1,21 +1,5 @@
-# Copyright (C) 2010 Sun Microsystems, Inc.
-# Use is subject to license terms
-#
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; version 2 of the License.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program; if not, write to the Free Software
-# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 
 if (!`SELECT count(*) FROM information_schema.engines WHERE
-      (support = 'YES' OR support = 'DEFAULT') AND
       engine = 'PERFORMANCE_SCHEMA'`){
   skip Need performance schema compiled in;
 }

mysql-test/suite/perfschema/r/start_server_off.result

@@ -4,6 +4,7 @@ information_schema
 mtr
 mysql
 performance_schema
+sys
 test
 select count(*) from performance_schema.performance_timers;
 count(*)
@@ -95,16 +96,16 @@ select * from performance_schema.replication_applier_configuration;
 select * from performance_schema.replication_applier_status;
 select * from performance_schema.replication_applier_status_by_coordinator;
 select * from performance_schema.replication_applier_status_by_worker;
-select * from performance_schema.status_global;
+select * from performance_schema.global_status;
 select * from performance_schema.status_by_thread;
 select * from performance_schema.status_by_user;
 select * from performance_schema.status_by_host;
 select * from performance_schema.status_by_account;
 select * from performance_schema.session_status;
-select * from performance_schema.variables_global;
+select * from performance_schema.global_variables;
 select * from performance_schema.variables_by_thread;
 select * from performance_schema.session_variables;
-show variables like "performance_schema%";
+show global variables like "performance_schema%";
 Variable_name	Value
 performance_schema	OFF
 performance_schema_accounts_size	100
@@ -124,30 +125,37 @@ performance_schema_max_digest_length	1024
 performance_schema_max_file_classes	50
 performance_schema_max_file_handles	32768
 performance_schema_max_file_instances	10000
-performance_schema_max_memory_classes	250
-performance_schema_max_metadata_locks	-1
+performance_schema_max_index_stat	5000
+performance_schema_max_memory_classes	320
+performance_schema_max_metadata_locks	10000
 performance_schema_max_mutex_classes	200
 performance_schema_max_mutex_instances	5000
+performance_schema_max_prepared_statements_instances	100
 performance_schema_max_program_instances	5000
 performance_schema_max_rwlock_classes	40
 performance_schema_max_rwlock_instances	5000
 performance_schema_max_socket_classes	10
 performance_schema_max_socket_instances	1000
+performance_schema_max_sql_text_length	1024
 performance_schema_max_stage_classes	150
-performance_schema_max_statement_classes	189
+performance_schema_max_statement_classes	191
 performance_schema_max_statement_stack	10
 performance_schema_max_table_handles	1000
 performance_schema_max_table_instances	500
+performance_schema_max_table_lock_stat	500
 performance_schema_max_thread_classes	50
 performance_schema_max_thread_instances	200
-performance_schema_max_transaction_classes	10
 performance_schema_session_connect_attrs_size	2048
 performance_schema_setup_actors_size	100
 performance_schema_setup_objects_size	100
 performance_schema_users_size	100
 show engine PERFORMANCE_SCHEMA status;
-show status like "performance_schema%";
-show status like "performance_schema%";
+show global status like "performance_schema%";
+select * from information_schema.engines
+where engine = "PERFORMANCE_SCHEMA";
+ENGINE	SUPPORT	COMMENT	TRANSACTIONS	XA	SAVEPOINTS
+PERFORMANCE_SCHEMA	YES	Performance Schema	NO	NO	NO
+show global status like "performance_schema%";
 Variable_name	Value
 Performance_schema_accounts_lost	0
 Performance_schema_cond_classes_lost	0
@@ -157,12 +165,14 @@ Performance_schema_file_classes_lost	0
 Performance_schema_file_handles_lost	0
 Performance_schema_file_instances_lost	0
 Performance_schema_hosts_lost	0
+Performance_schema_index_stat_lost	0
 Performance_schema_locker_lost	0
 Performance_schema_memory_classes_lost	0
 Performance_schema_metadata_lock_lost	0
 Performance_schema_mutex_classes_lost	0
 Performance_schema_mutex_instances_lost	0
 Performance_schema_nested_statement_lost	0
+Performance_schema_prepared_statements_lost	0
 Performance_schema_program_lost	0
 Performance_schema_rwlock_classes_lost	0
 Performance_schema_rwlock_instances_lost	0
@@ -173,30 +183,30 @@ Performance_schema_stage_classes_lost	0
 Performance_schema_statement_classes_lost	0
 Performance_schema_table_handles_lost	0
 Performance_schema_table_instances_lost	0
+Performance_schema_table_lock_stat_lost	0
 Performance_schema_thread_classes_lost	0
 Performance_schema_thread_instances_lost	0
-Performance_schema_transaction_classes_lost	0
 Performance_schema_users_lost	0
 select * from performance_schema.setup_consumers;
 NAME	ENABLED
 select * from performance_schema.setup_instruments;
 NAME	ENABLED	TIMED
 select * from performance_schema.setup_actors;
-HOST	USER	ROLE
+HOST	USER	ROLE	ENABLED	HISTORY
 select * from performance_schema.setup_objects;
 OBJECT_TYPE	OBJECT_SCHEMA	OBJECT_NAME	ENABLED	TIMED
 select * from performance_schema.setup_timers;
 NAME	TIMER_NAME
 insert into performance_schema.setup_objects values ('TABLE', 'myschema', 'myobject', 'YES', 'YES');
 ERROR HY000: Invalid performance_schema usage.
-insert into performance_schema.setup_actors values ('myhost', 'mysuser', 'myrole');
+insert into performance_schema.setup_actors values ('myhost', 'mysuser', 'myrole', 'YES', 'YES');
 ERROR HY000: Invalid performance_schema usage.
 select * from performance_schema.setup_objects;
 OBJECT_TYPE	OBJECT_SCHEMA	OBJECT_NAME	ENABLED	TIMED
 update performance_schema.setup_objects set OBJECT_NAME = 'myobject';
 delete from performance_schema.setup_objects;
 select * from performance_schema.setup_actors;
-HOST	USER	ROLE
+HOST	USER	ROLE	ENABLED	HISTORY
 update performance_schema.setup_actors set HOST = 'myhost';
 delete from performance_schema.setup_actors;
 truncate performance_schema.events_stages_history_long;

mysql-test/suite/perfschema/t/start_server_off.test

@@ -5,6 +5,9 @@
 
 --source ../include/start_server_common.inc
 
+select * from information_schema.engines
+  where engine = "PERFORMANCE_SCHEMA";
+
 # Expecting all off / zero
 show global status like "performance_schema%";
 
@@ -26,7 +29,7 @@ select * from performance_schema.setup_timers;
 insert into performance_schema.setup_objects values ('TABLE', 'myschema', 'myobject', 'YES', 'YES');
 
 --error ER_WRONG_PERFSCHEMA_USAGE
-insert into performance_schema.setup_actors values ('myhost', 'mysuser', 'myrole');
+insert into performance_schema.setup_actors values ('myhost', 'mysuser', 'myrole', 'YES', 'YES');
 
 # Expect SELECT, UPDATE, DELETE and TRUNCATE to affect 0 rows, but with
 # no error because the target row(s) will not be found

scripts/mysql_system_tables.sql

@@ -321,7 +321,7 @@ DROP PREPARE stmt;
 -- if the server is built with performance schema
 --
 
-set @have_pfs= (select count(engine) from information_schema.engines where engine='PERFORMANCE_SCHEMA' and support != 'NO');
+set @have_pfs= (select count(engine) from information_schema.engines where engine='PERFORMANCE_SCHEMA');
 
 --
 -- TABLE COND_INSTANCES

sql/mysqld.cc

@@ -709,8 +709,6 @@ static int remaining_argc;
 /** Remaining command line arguments (arguments), filtered by handle_options().*/
 static char **remaining_argv;
 
-bool load_perfschema_engine= false;
-
 int orig_argc;
 char **orig_argv;
 
@@ -4405,9 +4403,6 @@ int mysqld_main(int argc, char **argv)
   adjust_related_options(&requested_open_files);
 
 #ifdef WITH_PERFSCHEMA_STORAGE_ENGINE
-  if (pfs_param.m_enabled)
-    load_perfschema_engine= true;
-
   if (ho_error == 0)
   {
     if (pfs_param.m_enabled && !opt_help && !opt_bootstrap)
@@ -4850,7 +4845,7 @@ int mysqld_main(int argc, char **argv)
     - the tables are not supposed to exist yet, bootstrap will create them
     - a check would print spurious error messages
   */
-  if (! opt_bootstrap && load_perfschema_engine)
+  if (! opt_bootstrap)
     check_performance_schema();
 #endif
 

sql/mysqld.h

@@ -352,8 +352,6 @@ static inline int my_thread_set_THR_THD(THD *thd)
   return my_set_thread_local(THR_THD, thd);
 }
 
-extern bool load_perfschema_engine;
-
 #ifdef HAVE_PSI_INTERFACE
 
 C_MODE_START

sql/sql_plugin.cc

@@ -1410,33 +1410,6 @@ int plugin_init(int *argc, char **argv, int flags)
       tmp.state= 0;
       tmp.load_option= mandatory ? PLUGIN_FORCE : PLUGIN_ON;
 
-      /*
-        If the performance schema is compiled in,
-        treat the storage engine plugin as 'mandatory',
-        to suppress any plugin-level options such as '--performance-schema'.
-        This is specific to the performance schema, and is done on purpose:
-        the server-level option '--performance-schema' controls the overall
-        performance schema initialization, which consists of much more that
-        the underlying storage engine initialization.
-        See mysqld.cc, set_vars.cc.
-        Suppressing ways to interfere directly with the storage engine alone
-        prevents awkward situations where:
-        - the user wants the performance schema functionality, by using
-          '--enable-performance-schema' (the server option),
-        - yet disable explicitly a component needed for the functionality
-          to work, by using '--skip-performance-schema' (the plugin)
-      */
-      if (!my_strcasecmp(&my_charset_latin1, plugin->name, "PERFORMANCE_SCHEMA"))
-      {
-        if (load_perfschema_engine)
-          tmp.load_option= PLUGIN_FORCE;
-        else
-        {
-          tmp.load_option= PLUGIN_OFF;
-          continue;
-        }
-      }
-
       free_root(&tmp_root, MYF(MY_MARK_BLOCKS_FREE));
       if (test_plugin_options(&tmp_root, &tmp, argc, argv))
         tmp.state= PLUGIN_IS_DISABLED;

storage/perfschema/CMakeLists.txt

@@ -269,7 +269,7 @@ table_replication_applier_status_by_worker.cc
 table_replication_group_member_stats.cc
 )
 
-MYSQL_ADD_PLUGIN(perfschema ${PERFSCHEMA_SOURCES} STORAGE_ENGINE DEFAULT STATIC_ONLY NOT_FOR_EMBEDDED)
+MYSQL_ADD_PLUGIN(perfschema ${PERFSCHEMA_SOURCES} STORAGE_ENGINE MANDATORY STATIC_ONLY NOT_FOR_EMBEDDED)
 IF(WITH_PERFSCHEMA_STORAGE_ENGINE AND WITH_UNIT_TESTS)
   ENABLE_TESTING()
   ADD_SUBDIRECTORY(unittest)