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  • 使用性能模式监视InnoDB Mutex等待

    互斥锁是代码中使用的一种同步机制,用于强制在给定时间只有一个线程可以访问公共资源。当服务器中执行的两个或多个线程需要访问同一资源时,这些线程会相互竞争。在互斥锁上获得锁的第一个线程使其他线程等待,直到锁被释放。

    对于InnoDB已检测到的互斥锁,可以使用Performance Schema监视互斥锁等待。例如,性能模式表中收集的等待事件数据可以帮助识别等待时间最多或总等待时间最多的互斥体。

    以下示例演示了如何启用InnoDB互斥锁等待工具,如何启用关联的使用者以及如何查询等待事件数据。

    1. 要参见可用的InnoDB互斥锁等待工具,请查询性能架构setup_instruments表。InnoDB默认情况下,所有互斥锁等待工具都处于禁用状态。

      mysql> SELECT *
             FROM performance_schema.setup_instruments
             WHERE NAME LIKE '%wait/synch/mutex/innodb%';
      +---------------------------------------------------------	+---------	+-------	+
      | NAME                                                    	| ENABLED 	| TIMED 	|
      +---------------------------------------------------------	+---------	+-------	+
      | wait/synch/mutex/innodb/commit_cond_mutex               	| NO      	| NO    	|
      | wait/synch/mutex/innodb/innobase_share_mutex            	| NO      	| NO    	|
      | wait/synch/mutex/innodb/autoinc_mutex                   	| NO      	| NO    	|
      | wait/synch/mutex/innodb/autoinc_persisted_mutex         	| NO      	| NO    	|
      | wait/synch/mutex/innodb/buf_pool_flush_state_mutex      	| NO      	| NO    	|
      | wait/synch/mutex/innodb/buf_pool_LRU_list_mutex         	| NO      	| NO    	|
      | wait/synch/mutex/innodb/buf_pool_free_list_mutex        	| NO      	| NO    	|
      | wait/synch/mutex/innodb/buf_pool_zip_free_mutex         	| NO      	| NO    	|
      | wait/synch/mutex/innodb/buf_pool_zip_hash_mutex         	| NO      	| NO    	|
      | wait/synch/mutex/innodb/buf_pool_zip_mutex              	| NO      	| NO    	|
      | wait/synch/mutex/innodb/cache_last_read_mutex           	| NO      	| NO    	|
      | wait/synch/mutex/innodb/dict_foreign_err_mutex          	| NO      	| NO    	|
      | wait/synch/mutex/innodb/dict_persist_dirty_tables_mutex 	| NO      	| NO    	|
      | wait/synch/mutex/innodb/dict_sys_mutex                  	| NO      	| NO    	|
      | wait/synch/mutex/innodb/recalc_pool_mutex               	| NO      	| NO    	|
      | wait/synch/mutex/innodb/fil_system_mutex                	| NO      	| NO    	|
      | wait/synch/mutex/innodb/flush_list_mutex                	| NO      	| NO    	|
      | wait/synch/mutex/innodb/fts_bg_threads_mutex            	| NO      	| NO    	|
      | wait/synch/mutex/innodb/fts_delete_mutex                	| NO      	| NO    	|
      | wait/synch/mutex/innodb/fts_optimize_mutex              	| NO      	| NO    	|
      | wait/synch/mutex/innodb/fts_doc_id_mutex                	| NO      	| NO    	|
      | wait/synch/mutex/innodb/log_flush_order_mutex           	| NO      	| NO    	|
      | wait/synch/mutex/innodb/hash_table_mutex                	| NO      	| NO    	|
      | wait/synch/mutex/innodb/ibuf_bitmap_mutex               	| NO      	| NO    	|
      | wait/synch/mutex/innodb/ibuf_mutex                      	| NO      	| NO    	|
      | wait/synch/mutex/innodb/ibuf_pessimistic_insert_mutex   	| NO      	| NO    	|
      | wait/synch/mutex/innodb/log_sys_mutex                   	| NO      	| NO    	|
      | wait/synch/mutex/innodb/log_sys_write_mutex             	| NO      	| NO    	|
      | wait/synch/mutex/innodb/mutex_list_mutex                	| NO      	| NO    	|
      | wait/synch/mutex/innodb/page_zip_stat_per_index_mutex   	| NO      	| NO    	|
      | wait/synch/mutex/innodb/purge_sys_pq_mutex              	| NO      	| NO    	|
      | wait/synch/mutex/innodb/recv_sys_mutex                  	| NO      	| NO    	|
      | wait/synch/mutex/innodb/recv_writer_mutex               	| NO      	| NO    	|
      | wait/synch/mutex/innodb/redo_rseg_mutex                 	| NO      	| NO    	|
      | wait/synch/mutex/innodb/noredo_rseg_mutex               	| NO      	| NO    	|
      | wait/synch/mutex/innodb/rw_lock_list_mutex              	| NO      	| NO    	|
      | wait/synch/mutex/innodb/rw_lock_mutex                   	| NO      	| NO    	|
      | wait/synch/mutex/innodb/srv_dict_tmpfile_mutex          	| NO      	| NO    	|
      | wait/synch/mutex/innodb/srv_innodb_monitor_mutex        	| NO      	| NO    	|
      | wait/synch/mutex/innodb/srv_misc_tmpfile_mutex          	| NO      	| NO    	|
      | wait/synch/mutex/innodb/srv_monitor_file_mutex          	| NO      	| NO    	|
      | wait/synch/mutex/innodb/buf_dblwr_mutex                 	| NO      	| NO    	|
      | wait/synch/mutex/innodb/trx_undo_mutex                  	| NO      	| NO    	|
      | wait/synch/mutex/innodb/trx_pool_mutex                  	| NO      	| NO    	|
      | wait/synch/mutex/innodb/trx_pool_manager_mutex          	| NO      	| NO    	|
      | wait/synch/mutex/innodb/srv_sys_mutex                   	| NO      	| NO    	|
      | wait/synch/mutex/innodb/lock_mutex                      	| NO      	| NO    	|
      | wait/synch/mutex/innodb/lock_wait_mutex                 	| NO      	| NO    	|
      | wait/synch/mutex/innodb/trx_mutex                       	| NO      	| NO    	|
      | wait/synch/mutex/innodb/srv_threads_mutex               	| NO      	| NO    	|
      | wait/synch/mutex/innodb/rtr_active_mutex                	| NO      	| NO    	|
      | wait/synch/mutex/innodb/rtr_match_mutex                 	| NO      	| NO    	|
      | wait/synch/mutex/innodb/rtr_path_mutex                  	| NO      	| NO    	|
      | wait/synch/mutex/innodb/rtr_ssn_mutex                   	| NO      	| NO    	|
      | wait/synch/mutex/innodb/trx_sys_mutex                   	| NO      	| NO    	|
      | wait/synch/mutex/innodb/zip_pad_mutex                   	| NO      	| NO    	|
      | wait/synch/mutex/innodb/master_key_id_mutex             	| NO      	| NO    	|
      +---------------------------------------------------------	+---------	+-------	+
      
    2. 一些InnoDB互斥锁实例是在服务器启动时创建的,只有在服务器启动时也启用了关联的工具的情况下,才进行检测。为确保InnoDB已检测并启用所有互斥体实例,请在performance-schema-instrument您的MySQL配置文件中添加以下规则:

      performance-schema-instrument='wait/synch/mutex/innodb/%=ON'
      

      如果不需要所有InnoDB互斥锁的等待事件数据,则可以通过向performance-schema-instrumentMySQL配置文件添加其他规则来禁用特定工具。例如,要禁用InnoDB与全文搜索相关的互斥锁等待事件工具,请添加以下规则:

      performance-schema-instrument='wait/synch/mutex/innodb/fts%=OFF'
      
      注意

      前缀较长的规则(例如)wait/synch/mutex/innodb/fts%优先于前缀较短的规则(例如)wait/synch/mutex/innodb/%

      performance-schema-instrument规则添加到配置文件后,重新启动服务器。InnoDB除与全文搜索相关的互斥锁外,所有互斥锁均已启用。要进行验证,请查询setup_instruments表。在ENABLEDTIMED列应设置YES为您启用的工具。

      mysql> SELECT *
             FROM performance_schema.setup_instruments
             WHERE NAME LIKE '%wait/synch/mutex/innodb%';
      +-------------------------------------------------------	+---------	+-------	+
      | NAME                                                  	| ENABLED 	| TIMED 	|
      +-------------------------------------------------------	+---------	+-------	+
      | wait/synch/mutex/innodb/commit_cond_mutex             	| YES     	| YES   	|
      | wait/synch/mutex/innodb/innobase_share_mutex          	| YES     	| YES   	|
      | wait/synch/mutex/innodb/autoinc_mutex                 	| YES     	| YES   	|
      ...
      | wait/synch/mutex/innodb/master_key_id_mutex           	| YES     	| YES   	|
      +-------------------------------------------------------	+---------	+-------	+
      49 rows in set (0.00 sec)
      
    3. 通过更新setup_consumers表来启用等待事件使用者。默认情况下,禁用等待事件使用者。

      mysql> UPDATE performance_schema.setup_consumers
             SET enabled = 'YES'
             WHERE name like 'events_waits%';
      Query OK, 3 rows affected (0.00 sec)
      Rows matched: 3  Changed: 3  Warnings: 0
      

      您可以通过查询setup_consumers表来验证是否启用了等待事件使用者。的events_waits_currentevents_waits_historyevents_waits_history_long消费者应该启用。

      mysql> SELECT * FROM performance_schema.setup_consumers;
      +----------------------------------	+---------	+
      | NAME                             	| ENABLED 	|
      +----------------------------------	+---------	+
      | events_stages_current            	| NO      	|
      | events_stages_history            	| NO      	|
      | events_stages_history_long       	| NO      	|
      | events_statements_current        	| YES     	|
      | events_statements_history        	| YES     	|
      | events_statements_history_long   	| NO      	|
      | events_transactions_current      	| YES     	|
      | events_transactions_history      	| YES     	|
      | events_transactions_history_long 	| NO      	|
      | events_waits_current             	| YES     	|
      | events_waits_history             	| YES     	|
      | events_waits_history_long        	| YES     	|
      | global_instrumentation           	| YES     	|
      | thread_instrumentation           	| YES     	|
      | statements_digest                	| YES     	|
      +----------------------------------	+---------	+
      15 rows in set (0.00 sec)
      
    4. 启用仪器和使用者后,运行要监视的工作负载。在此示例中,mysqlslap负载仿真客户端用于模拟工作负载。

      shell> ./mysqlslap --auto-generate-sql --concurrency=100 --iterations=10 
             --number-of-queries=1000 --number-char-cols=6 --number-int-cols=6;
      
    5. 查询等待事件数据。在这个例子中,等待事件数据从查询events_waits_summary_global_by_event_name其在发现聚集数据表events_waits_currentevents_waits_historyevents_waits_history_long表。数据通过事件名称(EVENT_NAME)进行汇总,事件名称是产生事件的仪器的名称。汇总数据包括:

      • COUNT_STAR

        汇总的等待事件数。

      • SUM_TIMER_WAIT

        汇总的定时等待事件的总等待时间。

      • MIN_TIMER_WAIT

        摘要定时等待事件的最小等待时间。

      • AVG_TIMER_WAIT

        汇总的定时等待事件的平均等待时间。

      • MAX_TIMER_WAIT

        摘要定时等待事件的最大等待时间。

      以下查询返回仪器名称(EVENT_NAME),等待事件数(COUNT_STAR)和该仪器事件的总等待时间(SUM_TIMER_WAIT)。因为默认情况下,等待时间以皮秒(万亿分之一秒)为单位,所以等待时间除以1000000000,以毫秒为单位显示等待时间。数据按汇总的等待事件数(COUNT_STAR)降序排列。您可以调整ORDER BY子句以按总等待时间对数据进行排序。

      mysql> SELECT EVENT_NAME, COUNT_STAR, SUM_TIMER_WAIT/1000000000 SUM_TIMER_WAIT_MS
             FROM performance_schema.events_waits_summary_global_by_event_name
             WHERE SUM_TIMER_WAIT > 0 AND EVENT_NAME LIKE 'wait/synch/mutex/innodb/%'
             ORDER BY COUNT_STAR DESC;
      +---------------------------------------------------------	+------------	+-------------------	+
      | EVENT_NAME                                              	| COUNT_STAR 	| SUM_TIMER_WAIT_MS 	|
      +---------------------------------------------------------	+------------	+-------------------	+
      | wait/synch/mutex/innodb/trx_mutex                       	|     201111 	|           23.4719 	|
      | wait/synch/mutex/innodb/fil_system_mutex                	|      62244 	|            9.6426 	|
      | wait/synch/mutex/innodb/redo_rseg_mutex                 	|      48238 	|            3.1135 	|
      | wait/synch/mutex/innodb/log_sys_mutex                   	|      46113 	|            2.0434 	|
      | wait/synch/mutex/innodb/trx_sys_mutex                   	|      35134 	|         1068.1588 	|
      | wait/synch/mutex/innodb/lock_mutex                      	|      34872 	|         1039.2589 	|
      | wait/synch/mutex/innodb/log_sys_write_mutex             	|      17805 	|         1526.0490 	|
      | wait/synch/mutex/innodb/dict_sys_mutex                  	|      14912 	|         1606.7348 	|
      | wait/synch/mutex/innodb/trx_undo_mutex                  	|      10634 	|            1.1424 	|
      | wait/synch/mutex/innodb/rw_lock_list_mutex              	|       8538 	|            0.1960 	|
      | wait/synch/mutex/innodb/buf_pool_free_list_mutex        	|       5961 	|            0.6473 	|
      | wait/synch/mutex/innodb/trx_pool_mutex                  	|       4885 	|         8821.7496 	|
      | wait/synch/mutex/innodb/buf_pool_LRU_list_mutex         	|       4364 	|            0.2077 	|
      | wait/synch/mutex/innodb/innobase_share_mutex            	|       3212 	|            0.2650 	|
      | wait/synch/mutex/innodb/flush_list_mutex                	|       3178 	|            0.2349 	|
      | wait/synch/mutex/innodb/trx_pool_manager_mutex          	|       2495 	|            0.1310 	|
      | wait/synch/mutex/innodb/buf_pool_flush_state_mutex      	|       1318 	|            0.2161 	|
      | wait/synch/mutex/innodb/log_flush_order_mutex           	|       1250 	|            0.0893 	|
      | wait/synch/mutex/innodb/buf_dblwr_mutex                 	|        951 	|            0.0918 	|
      | wait/synch/mutex/innodb/recalc_pool_mutex               	|        670 	|            0.0942 	|
      | wait/synch/mutex/innodb/dict_persist_dirty_tables_mutex 	|        345 	|            0.0414 	|
      | wait/synch/mutex/innodb/lock_wait_mutex                 	|        303 	|            0.1565 	|
      | wait/synch/mutex/innodb/autoinc_mutex                   	|        196 	|            0.0213 	|
      | wait/synch/mutex/innodb/autoinc_persisted_mutex         	|        196 	|            0.0175 	|
      | wait/synch/mutex/innodb/purge_sys_pq_mutex              	|        117 	|            0.0308 	|
      | wait/synch/mutex/innodb/srv_sys_mutex                   	|         94 	|            0.0077 	|
      | wait/synch/mutex/innodb/ibuf_mutex                      	|         22 	|            0.0086 	|
      | wait/synch/mutex/innodb/recv_sys_mutex                  	|         12 	|            0.0008 	|
      | wait/synch/mutex/innodb/srv_innodb_monitor_mutex        	|          4 	|            0.0009 	|
      | wait/synch/mutex/innodb/recv_writer_mutex               	|          1 	|            0.0005 	|
      +---------------------------------------------------------	+------------	+-------------------	+
      
      注意

      前面的结果集包括在启动过程中产生的等待事件数据。要排除此数据,您可以events_waits_summary_global_by_event_name在启动后和运行工作负载之前立即截断该表。但是,截断操作本身可能会产生数量可忽略的等待事件数据。

      mysql> TRUNCATE performance_schema.events_waits_summary_global_by_event_name;