背景: MySQL 5.5開始新增一個數(shù)據(jù)庫:PERFORMANCE_SCHEMA,主要用于收集數(shù)據(jù)庫服務(wù)器性能參數(shù)。并且?guī)炖锉淼拇鎯σ婢鶠镻ERFORMANCE_SCHEMA,而用戶是不能創(chuàng)建存儲引擎為PERFORMANCE_SCHEMA的表。MySQL5.5默認是關(guān)閉的,需要手動開啟,在配置文件里添加: [mysqld] performance_schema=ON 查看是否開啟: mysql>show variables like 'performance_schema'; +--------------------+-------+ | Variable_name | Value | +--------------------+-------+ | performance_schema | ON | +--------------------+-------+ 從MySQL5.6開始,默認打開,本文就從MySQL5.6來說明,在數(shù)據(jù)庫使用當中PERFORMANCE_SCHEMA的一些比較常用的功能。具體的信息可以查看官方文檔。 相關(guān)表信息: 一:配置(setup)表: zjy@performance_schema 10:16:56>show tables like '%setup%'; +----------------------------------------+ | Tables_in_performance_schema (%setup%) | +----------------------------------------+ | setup_actors | | setup_consumers | | setup_instruments | | setup_objects | | setup_timers | +----------------------------------------+ 1,setup_actors:配置用戶緯度的監(jiān)控,默認監(jiān)控所有用戶。 zjy@performance_schema 10:19:11>select * from setup_actors; +------+------+------+ | HOST | USER | ROLE | +------+------+------+ | % | % | % | +------+------+------+ 2,setup_consumers:配置events的消費者類型,即收集的events寫入到哪些統(tǒng)計表中。 zjy@: performance_schema 10:23:35>select * from setup_consumers; +--------------------------------+---------+ | NAME | ENABLED | +--------------------------------+---------+ | events_stages_current | NO | | events_stages_history | NO | | events_stages_history_long | NO | | events_statements_current | YES | | events_statements_history | NO | | events_statements_history_long | NO | | events_waits_current | NO | | events_waits_history | NO | | events_waits_history_long | NO | | global_instrumentation | YES | | thread_instrumentation | YES | | statements_digest | YES | +--------------------------------+---------+ 這里需要說明的是需要查看哪個就更新其ENABLED列為YES。如: zjy@performance_schema 10:25:02>update setup_consumers set ENABLED='YES' where NAME in ('events_stages_current','events_waits_current'); Query OK, 2 rows affected (0.00 sec) 更新完后立即生效,但是服務(wù)器重啟之后又會變回默認值,要永久生效需要在配置文件里添加: [mysqld] #performance_schema performance_schema_consumer_events_waits_current=on performance_schema_consumer_events_stages_current=on performance_schema_consumer_events_statements_current=on performance_schema_consumer_events_waits_history=on performance_schema_consumer_events_stages_history=on performance_schema_consumer_events_statements_history=on 即在這些表的前面加上:performance_schema_consumer_xxx。表setup_consumers里面的值有個層級關(guān)系: global_instrumentation > thread_instrumentation = statements_digest > events_stages_current = events_statements_current = events_waits_current > events_stages_history = events_statements_history = events_waits_history > events_stages_history_long = events_statements_history_long = events_waits_history_long 只有上一層次的為YES,才會繼續(xù)檢查該本層為YES or NO。global_instrumentation是最高級別consumer,如果它設(shè)置為NO,則所有的consumer都會忽略。其中history和history_long存的是current表的歷史記錄條數(shù),history表記錄了每個線程最近等待的10個事件,而history_long表則記錄了最近所有線程產(chǎn)生的10000個事件,這里的10和10000都是可以配置的。這三個表表結(jié)構(gòu)相同,history和history_long表數(shù)據(jù)都來源于current表。長度通過控制參數(shù): zjy@performance_schema 11:10:03>show variables like 'performance_schema%history%size'; +--------------------------------------------------------+-------+ | Variable_name | Value | +--------------------------------------------------------+-------+ | performance_schema_events_stages_history_long_size | 10000 | | performance_schema_events_stages_history_size | 10 | | performance_schema_events_statements_history_long_size | 10000 | | performance_schema_events_statements_history_size | 10 | | performance_schema_events_waits_history_long_size | 10000 | | performance_schema_events_waits_history_size | 10 | +--------------------------------------------------------+-------+ 3,setup_instruments:配置具體的instrument,主要包含4大類:idle、stage/xxx、statement/xxx、wait/xxx: zjy@performance_schema 10:56:35>select name,count(*) from setup_instruments group by LEFT(name,5); +---------------------------------+----------+ | name | count(*) | +---------------------------------+----------+ | idle | 1 | | stage/sql/After create | 111 | | statement/sql/select | 179 | | wait/synch/mutex/sql/PAGE::lock | 296 | +---------------------------------+----------+ idle表示socket空閑的時間,stage類表示語句的每個執(zhí)行階段的統(tǒng)計,statement類統(tǒng)計語句維度的信息,wait類統(tǒng)計各種等待事件,比如IO,mutux,spin_lock,condition等。 4,setup_objects:配置監(jiān)控對象,默認對mysql,performance_schema和information_schema中的表都不監(jiān)控,而其它DB的所有表都監(jiān)控。 zjy@performance_schema 11:00:18>select * from setup_objects; +-------------+--------------------+-------------+---------+-------+ | OBJECT_TYPE | OBJECT_SCHEMA | OBJECT_NAME | ENABLED | TIMED | +-------------+--------------------+-------------+---------+-------+ | TABLE | mysql | % | NO | NO | | TABLE | performance_schema | % | NO | NO | | TABLE | information_schema | % | NO | NO | | TABLE | % | % | YES | YES | +-------------+--------------------+-------------+---------+-------+ 5,setup_timers:配置每種類型指令的統(tǒng)計時間單位。MICROSECOND表示統(tǒng)計單位是微妙,CYCLE表示統(tǒng)計單位是時鐘周期,時間度量與CPU的主頻有關(guān),NANOSECOND表示統(tǒng)計單位是納秒。但無論采用哪種度量單位,最終統(tǒng)計表中統(tǒng)計的時間都會裝換到皮秒。(1秒=1000000000000皮秒) zjy@performance_schema 11:05:12>select * from setup_timers; +-----------+-------------+ | NAME | TIMER_NAME | +-----------+-------------+ | idle | MICROSECOND | | wait | CYCLE | | stage | NANOSECOND | | statement | NANOSECOND | +-----------+-------------+ 二:instance表 1,cond_instances:條件等待對象實例 表中記錄了系統(tǒng)中使用的條件變量的對象,OBJECT_INSTANCE_BEGIN為對象的內(nèi)存地址。 2,file_instances:文件實例 表中記錄了系統(tǒng)中打開了文件的對象,包括ibdata文件,redo文件,binlog文件,用戶的表文件等,open_count顯示當前文件打開的數(shù)目,如果重來沒有打開過,不會出現(xiàn)在表中。 zjy@performance_schema 11:20:04>select * from file_instances limit 2,5; +---------------------------------+--------------------------------------+------------+ | FILE_NAME | EVENT_NAME | OPEN_COUNT | +---------------------------------+--------------------------------------+------------+ | /var/lib/mysql/mysql/plugin.frm | wait/io/file/sql/FRM | 0 | | /var/lib/mysql/mysql/plugin.MYI | wait/io/file/myisam/kfile | 1 | | /var/lib/mysql/mysql/plugin.MYD | wait/io/file/myisam/dfile | 1 | | /var/lib/mysql/ibdata1 | wait/io/file/innodb/innodb_data_file | 2 | | /var/lib/mysql/ib_logfile0 | wait/io/file/innodb/innodb_log_file | 2 | +---------------------------------+--------------------------------------+------------+ 3,mutex_instances:互斥同步對象實例 表中記錄了系統(tǒng)中使用互斥量對象的所有記錄,其中name為:wait/synch/mutex/*。LOCKED_BY_THREAD_ID顯示哪個線程正持有mutex,若沒有線程持有,則為NULL。 4,rwlock_instances: 讀寫鎖同步對象實例 表中記錄了系統(tǒng)中使用讀寫鎖對象的所有記錄,其中name為 wait/synch/rwlock/*。WRITE_LOCKED_BY_THREAD_ID為正在持有該對象的thread_id,若沒有線程持有,則為NULL。READ_LOCKED_BY_COUNT為記錄了同時有多少個讀者持有讀鎖。(通過 events_waits_current 表可以知道,哪個線程在等待鎖;通過rwlock_instances知道哪個線程持有鎖。rwlock_instances的缺陷是,只能記錄持有寫鎖的線程,對于讀鎖則無能為力)。 5,socket_instances:活躍會話對象實例 三:Wait表 1,events_waits_current:記錄了當前線程等待的事件 2,events_waits_history:記錄了每個線程最近等待的10個事件 3,events_waits_history_long:記錄了最近所有線程產(chǎn)生的10000個事件 表結(jié)構(gòu)定義如下: CREATE TABLE `events_waits_current` ( `THREAD_ID` bigint(20) unsigned NOT NULL COMMENT '線程ID', `EVENT_ID` bigint(20) unsigned NOT NULL COMMENT '當前線程的事件ID,和THREAD_ID確定唯一', `END_EVENT_ID` bigint(20) unsigned DEFAULT NULL COMMENT '當事件開始時,這一列被設(shè)置為NULL。當事件結(jié)束時,再更新為當前的事件ID', `EVENT_NAME` varchar(128) NOT NULL COMMENT '事件名稱', `SOURCE` varchar(64) DEFAULT NULL COMMENT '該事件產(chǎn)生時的源碼文件', `TIMER_START` bigint(20) unsigned DEFAULT NULL COMMENT '事件開始時間(皮秒)', `TIMER_END` bigint(20) unsigned DEFAULT NULL COMMENT '事件結(jié)束結(jié)束時間(皮秒)', `TIMER_WAIT` bigint(20) unsigned DEFAULT NULL COMMENT '事件等待時間(皮秒)', `SPINS` int(10) unsigned DEFAULT NULL COMMENT '', `OBJECT_SCHEMA` varchar(64) DEFAULT NULL COMMENT '庫名', `OBJECT_NAME` varchar(512) DEFAULT NULL COMMENT '文件名、表名、IP:SOCK值', `OBJECT_TYPE` varchar(64) DEFAULT NULL COMMENT 'FILE、TABLE、TEMPORARY TABLE', `INDEX_NAME` varchar(64) DEFAULT NULL COMMENT '索引名', `OBJECT_INSTANCE_BEGIN` bigint(20) unsigned NOT NULL COMMENT '內(nèi)存地址', `NESTING_EVENT_ID` bigint(20) unsigned DEFAULT NULL COMMENT '該事件對應(yīng)的父事件ID', `NESTING_EVENT_TYPE` enum('STATEMENT','STAGE','WAIT') DEFAULT NULL COMMENT '父事件類型(STATEMENT, STAGE, WAIT)', `OPERATION` varchar(32) NOT NULL COMMENT '操作類型(lock, read, write)', `NUMBER_OF_BYTES` bigint(20) DEFAULT NULL COMMENT '', `FLAGS` int(10) unsigned DEFAULT NULL COMMENT '標記' ) ENGINE=PERFORMANCE_SCHEMA DEFAULT CHARSET=utf8 四:Stage 表 1,events_stages_current:記錄了當前線程所處的執(zhí)行階段 2,events_stages_history:記錄了當前線程所處的執(zhí)行階段10條歷史記錄 3,events_stages_history_long:記錄了當前線程所處的執(zhí)行階段10000條歷史記錄 表結(jié)構(gòu)定義如下: CREATE TABLE `events_stages_current` ( `THREAD_ID` bigint(20) unsigned NOT NULL COMMENT '線程ID', `EVENT_ID` bigint(20) unsigned NOT NULL COMMENT '事件ID', `END_EVENT_ID` bigint(20) unsigned DEFAULT NULL COMMENT '結(jié)束事件ID', `EVENT_NAME` varchar(128) NOT NULL COMMENT '事件名稱', `SOURCE` varchar(64) DEFAULT NULL COMMENT '源碼位置', `TIMER_START` bigint(20) unsigned DEFAULT NULL COMMENT '事件開始時間(皮秒)', `TIMER_END` bigint(20) unsigned DEFAULT NULL COMMENT '事件結(jié)束結(jié)束時間(皮秒)', `TIMER_WAIT` bigint(20) unsigned DEFAULT NULL COMMENT '事件等待時間(皮秒)', `NESTING_EVENT_ID` bigint(20) unsigned DEFAULT NULL COMMENT '該事件對應(yīng)的父事件ID', `NESTING_EVENT_TYPE` enum('STATEMENT','STAGE','WAIT') DEFAULT NULL COMMENT '父事件類型(STATEMENT, STAGE, WAIT)' ) ENGINE=PERFORMANCE_SCHEMA DEFAULT CHARSET=utf8 五:Statement 表 1,events_statements_current:通過 thread_id+event_id可以唯一確定一條記錄。Statments表只記錄最頂層的請求,SQL語句或是COMMAND,每條語句一行。event_name形式為statement/sql/*,或statement/com/* 2,events_statements_history 3,events_statements_history_long 表結(jié)構(gòu)定義如下: CREATE TABLE `events_statements_current` ( `THREAD_ID` bigint(20) unsigned NOT NULL COMMENT '線程ID', `EVENT_ID` bigint(20) unsigned NOT NULL COMMENT '事件ID', `END_EVENT_ID` bigint(20) unsigned DEFAULT NULL COMMENT '結(jié)束事件ID', `EVENT_NAME` varchar(128) NOT NULL COMMENT '事件名稱', `SOURCE` varchar(64) DEFAULT NULL COMMENT '源碼位置', `TIMER_START` bigint(20) unsigned DEFAULT NULL COMMENT '事件開始時間(皮秒)', `TIMER_END` bigint(20) unsigned DEFAULT NULL COMMENT '事件結(jié)束結(jié)束時間(皮秒)', `TIMER_WAIT` bigint(20) unsigned DEFAULT NULL COMMENT '事件等待時間(皮秒)', `LOCK_TIME` bigint(20) unsigned NOT NULL COMMENT '鎖時間', `SQL_TEXT` longtext COMMENT '記錄SQL語句', `DIGEST` varchar(32) DEFAULT NULL COMMENT '對SQL_TEXT做MD5產(chǎn)生的32位字符串', `DIGEST_TEXT` longtext COMMENT '將語句中值部分用問號代替,用于SQL語句歸類', `CURRENT_SCHEMA` varchar(64) DEFAULT NULL COMMENT '默認的數(shù)據(jù)庫名', `OBJECT_TYPE` varchar(64) DEFAULT NULL COMMENT '保留字段', `OBJECT_SCHEMA` varchar(64) DEFAULT NULL COMMENT '保留字段', `OBJECT_NAME` varchar(64) DEFAULT NULL COMMENT '保留字段', `OBJECT_INSTANCE_BEGIN` bigint(20) unsigned DEFAULT NULL COMMENT '內(nèi)存地址', `MYSQL_ERRNO` int(11) DEFAULT NULL COMMENT '', `RETURNED_SQLSTATE` varchar(5) DEFAULT NULL COMMENT '', `MESSAGE_TEXT` varchar(128) DEFAULT NULL COMMENT '信息', `ERRORS` bigint(20) unsigned NOT NULL COMMENT '錯誤數(shù)目', `WARNINGS` bigint(20) unsigned NOT NULL COMMENT '警告數(shù)目', `ROWS_AFFECTED` bigint(20) unsigned NOT NULL COMMENT '影響的數(shù)目', `ROWS_SENT` bigint(20) unsigned NOT NULL COMMENT '返回的記錄數(shù)', `ROWS_EXAMINED` bigint(20) unsigned NOT NULL COMMENT '讀取掃描的記錄數(shù)目', `CREATED_TMP_DISK_TABLES` bigint(20) unsigned NOT NULL COMMENT '創(chuàng)建磁盤臨時表數(shù)目', `CREATED_TMP_TABLES` bigint(20) unsigned NOT NULL COMMENT '創(chuàng)建臨時表數(shù)目', `SELECT_FULL_JOIN` bigint(20) unsigned NOT NULL COMMENT 'join時,第一個表為全表掃描的數(shù)目', `SELECT_FULL_RANGE_JOIN` bigint(20) unsigned NOT NULL COMMENT '引用表采用range方式掃描的數(shù)目', `SELECT_RANGE` bigint(20) unsigned NOT NULL COMMENT 'join時,第一個表采用range方式掃描的數(shù)目', `SELECT_RANGE_CHECK` bigint(20) unsigned NOT NULL COMMENT '', `SELECT_SCAN` bigint(20) unsigned NOT NULL COMMENT 'join時,第一個表位全表掃描的數(shù)目', `SORT_MERGE_PASSES` bigint(20) unsigned NOT NULL COMMENT '', `SORT_RANGE` bigint(20) unsigned NOT NULL COMMENT '范圍排序數(shù)目', `SORT_ROWS` bigint(20) unsigned NOT NULL COMMENT '排序的記錄數(shù)目', `SORT_SCAN` bigint(20) unsigned NOT NULL COMMENT '全表排序數(shù)目', `NO_INDEX_USED` bigint(20) unsigned NOT NULL COMMENT '沒有使用索引數(shù)目', `NO_GOOD_INDEX_USED` bigint(20) unsigned NOT NULL COMMENT '', `NESTING_EVENT_ID` bigint(20) unsigned DEFAULT NULL COMMENT '該事件對應(yīng)的父事件ID', `NESTING_EVENT_TYPE` enum('STATEMENT','STAGE','WAIT') DEFAULT NULL COMMENT '父事件類型(STATEMENT, STAGE, WAIT)' ) ENGINE=PERFORMANCE_SCHEMA DEFAULT CHARSET=utf8 六:Connection 表 1,users:記錄用戶連接數(shù)信息 2,hosts:記錄了主機連接數(shù)信息 3,accounts:記錄了用戶主機連接數(shù)信息
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七:Summary 表: Summary表聚集了各個維度的統(tǒng)計信息包括表維度,索引維度,會話維度,語句維度和鎖維度的統(tǒng)計信息 1,events_waits_summary_global_by_event_name:按等待事件類型聚合,每個事件一條記錄 CREATE TABLE `events_waits_summary_global_by_event_name` ( `EVENT_NAME` varchar(128) NOT NULL COMMENT '事件名稱', `COUNT_STAR` bigint(20) unsigned NOT NULL COMMENT '事件計數(shù)', `SUM_TIMER_WAIT` bigint(20) unsigned NOT NULL COMMENT '總的等待時間', `MIN_TIMER_WAIT` bigint(20) unsigned NOT NULL COMMENT '最小等待時間', `AVG_TIMER_WAIT` bigint(20) unsigned NOT NULL COMMENT '平均等待時間', `MAX_TIMER_WAIT` bigint(20) unsigned NOT NULL COMMENT '最大等待時間' ) ENGINE=PERFORMANCE_SCHEMA DEFAULT CHARSET=utf8 2,events_waits_summary_by_instance:按等待事件對象聚合,同一種等待事件,可能有多個實例,每個實例有不同的內(nèi)存地址,因此 CREATE TABLE `events_waits_summary_by_instance` ( `EVENT_NAME` varchar(128) NOT NULL COMMENT '事件名稱', `OBJECT_INSTANCE_BEGIN` bigint(20) unsigned NOT NULL COMMENT '內(nèi)存地址', `COUNT_STAR` bigint(20) unsigned NOT NULL COMMENT '事件計數(shù)', `SUM_TIMER_WAIT` bigint(20) unsigned NOT NULL COMMENT '總的等待時間', `MIN_TIMER_WAIT` bigint(20) unsigned NOT NULL COMMENT '最小等待時間', `AVG_TIMER_WAIT` bigint(20) unsigned NOT NULL COMMENT '平均等待時間', `MAX_TIMER_WAIT` bigint(20) unsigned NOT NULL COMMENT '最大等待時間' ) ENGINE=PERFORMANCE_SCHEMA DEFAULT CHARSET=utf8 3,events_waits_summary_by_thread_by_event_name:按每個線程和事件來統(tǒng)計,thread_id+event_name唯一確定一條記錄。 CREATE TABLE `events_waits_summary_by_thread_by_event_name` ( `THREAD_ID` bigint(20) unsigned NOT NULL COMMENT '線程ID', `EVENT_NAME` varchar(128) NOT NULL COMMENT '事件名稱', `COUNT_STAR` bigint(20) unsigned NOT NULL COMMENT '事件計數(shù)', `SUM_TIMER_WAIT` bigint(20) unsigned NOT NULL COMMENT '總的等待時間', `MIN_TIMER_WAIT` bigint(20) unsigned NOT NULL COMMENT '最小等待時間', `AVG_TIMER_WAIT` bigint(20) unsigned NOT NULL COMMENT '平均等待時間', `MAX_TIMER_WAIT` bigint(20) unsigned NOT NULL COMMENT '最大等待時間' ) ENGINE=PERFORMANCE_SCHEMA DEFAULT CHARSET=utf8 4,events_stages_summary_global_by_event_name:按事件階段類型聚合,每個事件一條記錄,表結(jié)構(gòu)同上。 5,events_stages_summary_by_thread_by_event_name:按每個線程和事件來階段統(tǒng)計,表結(jié)構(gòu)同上。 6,events_statements_summary_by_digest:按照事件的語句進行聚合。 CREATE TABLE `events_statements_summary_by_digest` ( `SCHEMA_NAME` varchar(64) DEFAULT NULL COMMENT '庫名', `DIGEST` varchar(32) DEFAULT NULL COMMENT '對SQL_TEXT做MD5產(chǎn)生的32位字符串。如果為consumer表中沒有打開statement_digest選項,則為NULL', `DIGEST_TEXT` longtext COMMENT '將語句中值部分用問號代替,用于SQL語句歸類。如果為consumer表中沒有打開statement_digest選項,則為NULL。', `COUNT_STAR` bigint(20) unsigned NOT NULL COMMENT '事件計數(shù)', `SUM_TIMER_WAIT` bigint(20) unsigned NOT NULL COMMENT '總的等待時間', `MIN_TIMER_WAIT` bigint(20) unsigned NOT NULL COMMENT '最小等待時間', `AVG_TIMER_WAIT` bigint(20) unsigned NOT NULL COMMENT '平均等待時間', `MAX_TIMER_WAIT` bigint(20) unsigned NOT NULL COMMENT '最大等待時間', `SUM_LOCK_TIME` bigint(20) unsigned NOT NULL COMMENT '鎖時間總時長', `SUM_ERRORS` bigint(20) unsigned NOT NULL COMMENT '錯誤數(shù)的總', `SUM_WARNINGS` bigint(20) unsigned NOT NULL COMMENT '警告的總數(shù)', `SUM_ROWS_AFFECTED` bigint(20) unsigned NOT NULL COMMENT '影響的總數(shù)目', `SUM_ROWS_SENT` bigint(20) unsigned NOT NULL COMMENT '返回總數(shù)目', `SUM_ROWS_EXAMINED` bigint(20) unsigned NOT NULL COMMENT '總的掃描的數(shù)目', `SUM_CREATED_TMP_DISK_TABLES` bigint(20) unsigned NOT NULL COMMENT '創(chuàng)建磁盤臨時表的總數(shù)目', `SUM_CREATED_TMP_TABLES` bigint(20) unsigned NOT NULL COMMENT '創(chuàng)建臨時表的總數(shù)目', `SUM_SELECT_FULL_JOIN` bigint(20) unsigned NOT NULL COMMENT '第一個表全表掃描的總數(shù)目', `SUM_SELECT_FULL_RANGE_JOIN` bigint(20) unsigned NOT NULL COMMENT '總的采用range方式掃描的數(shù)目', `SUM_SELECT_RANGE` bigint(20) unsigned NOT NULL COMMENT '第一個表采用range方式掃描的總數(shù)目', `SUM_SELECT_RANGE_CHECK` bigint(20) unsigned NOT NULL COMMENT '', `SUM_SELECT_SCAN` bigint(20) unsigned NOT NULL COMMENT '第一個表位全表掃描的總數(shù)目', `SUM_SORT_MERGE_PASSES` bigint(20) unsigned NOT NULL COMMENT '', `SUM_SORT_RANGE` bigint(20) unsigned NOT NULL COMMENT '范圍排序總數(shù)', `SUM_SORT_ROWS` bigint(20) unsigned NOT NULL COMMENT '排序的記錄總數(shù)目', `SUM_SORT_SCAN` bigint(20) unsigned NOT NULL COMMENT '第一個表排序掃描總數(shù)目', `SUM_NO_INDEX_USED` bigint(20) unsigned NOT NULL COMMENT '沒有使用索引總數(shù)', `SUM_NO_GOOD_INDEX_USED` bigint(20) unsigned NOT NULL COMMENT '', `FIRST_SEEN` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00' COMMENT '第一次執(zhí)行時間', `LAST_SEEN` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00' COMMENT '最后一次執(zhí)行時間' ) ENGINE=PERFORMANCE_SCHEMA DEFAULT CHARSET=utf8 7,events_statements_summary_global_by_event_name:按照事件的語句進行聚合。表結(jié)構(gòu)同上。 8,events_statements_summary_by_thread_by_event_name:按照線程和事件的語句進行聚合,表結(jié)構(gòu)同上。 9,file_summary_by_instance:按事件類型統(tǒng)計(物理IO維度) 10,file_summary_by_event_name:具體文件統(tǒng)計(物理IO維度) 9和10一起說明: 統(tǒng)計IO操作:COUNT_STAR,SUM_TIMER_WAIT,MIN_TIMER_WAIT,AVG_TIMER_WAIT,MAX_TIMER_WAIT 統(tǒng)計讀 :COUNT_READ,SUM_TIMER_READ,MIN_TIMER_READ,AVG_TIMER_READ,MAX_TIMER_READ, SUM_NUMBER_OF_BYTES_READ 統(tǒng)計寫 :COUNT_WRITE,SUM_TIMER_WRITE,MIN_TIMER_WRITE,AVG_TIMER_WRITE,MAX_TIMER_WRITE, SUM_NUMBER_OF_BYTES_WRITE 統(tǒng)計其他IO事件,比如create,delete,open,close等:COUNT_MISC,SUM_TIMER_MISC,MIN_TIMER_MISC,AVG_TIMER_MISC,MAX_TIMER_MISC 11,table_io_waits_summary_by_table:根據(jù)wait/io/table/sql/handler,聚合每個表的I/O操作(邏輯IO緯度) 統(tǒng)計IO操作:COUNT_STAR,SUM_TIMER_WAIT,MIN_TIMER_WAIT,AVG_TIMER_WAIT,MAX_TIMER_WAIT 統(tǒng)計讀 :COUNT_READ,SUM_TIMER_READ,MIN_TIMER_READ,AVG_TIMER_READ,MAX_TIMER_READ :COUNT_FETCH,SUM_TIMER_FETCH,MIN_TIMER_FETCH,AVG_TIMER_FETCH, MAX_TIMER_FETCH 統(tǒng)計寫 :COUNT_WRITE,SUM_TIMER_WRITE,MIN_TIMER_WRITE,AVG_TIMER_WRITE,MAX_TIMER_WRITE INSERT統(tǒng)計,相應(yīng)的還有DELETE和UPDATE統(tǒng)計:COUNT_INSERT,SUM_TIMER_INSERT,MIN_TIMER_INSERT,AVG_TIMER_INSERT,MAX_TIMER_INSERT 12,table_io_waits_summary_by_index_usage:與table_io_waits_summary_by_table類似,按索引維度統(tǒng)計 13,table_lock_waits_summary_by_table:聚合了表鎖等待事件,包括internal lock 和 external lock internal lock通過SQL層函數(shù)thr_lock調(diào)用,OPERATION值為: 14,Connection Summaries表:account、user、host events_waits_summary_by_account_by_event_name 15,socket_summary_by_instance、socket_summary_by_event_name:socket聚合統(tǒng)計表。 八:其他相關(guān)表 1,performance_timers:系統(tǒng)支持的統(tǒng)計時間單位 2,threads:監(jiān)視服務(wù)端的當前運行的線程 統(tǒng)計應(yīng)用: 關(guān)于SQL維度的統(tǒng)計信息主要集中在events_statements_summary_by_digest表中,通過將SQL語句抽象出digest,可以統(tǒng)計某類SQL語句在各個維度的統(tǒng)計信息 1,哪個SQL執(zhí)行最多: zjy@performance_schema 11:36:22>SELECT SCHEMA_NAME,DIGEST_TEXT,COUNT_STAR,SUM_ROWS_SENT,SUM_ROWS_EXAMINED,FIRST_SEEN,LAST_SEEN FROM events_statements_summary_by_digest ORDER BY COUNT_STAR desc LIMIT 1\G *************************** 1. row *************************** SCHEMA_NAME: dchat DIGEST_TEXT: SELECT ... COUNT_STAR: 1161210102 SUM_ROWS_SENT: 1161207842 SUM_ROWS_EXAMINED: 0 FIRST_SEEN: 2016-02-17 00:36:46 LAST_SEEN: 2016-03-07 11:36:29 各個字段的注釋可以看上面的表結(jié)構(gòu)說明:從2月17號到3月7號該SQL執(zhí)行了1161210102次。 2,哪個SQL平均響應(yīng)時間最多: zjy@performance_schema 11:36:28>SELECT SCHEMA_NAME,DIGEST_TEXT,COUNT_STAR,AVG_TIMER_WAIT,SUM_ROWS_SENT,SUM_ROWS_EXAMINED,FIRST_SEEN,LAST_SEEN FROM events_statements_summary_by_digest ORDER BY AVG_TIMER_WAIT desc LIMIT 1\G *************************** 1. row *************************** SCHEMA_NAME: dchat DIGEST_TEXT: SELECT ... COUNT_STAR: 1 AVG_TIMER_WAIT: 273238183964000 SUM_ROWS_SENT: 50208 SUM_ROWS_EXAMINED: 5565651 FIRST_SEEN: 2016-02-22 13:27:33 LAST_SEEN: 2016-02-22 13:27:33 各個字段的注釋可以看上面的表結(jié)構(gòu)說明:從2月17號到3月7號該SQL平均響應(yīng)時間273238183964000皮秒(1000000000000皮秒=1秒) 3,哪個SQL掃描的行數(shù)最多: SUM_ROWS_EXAMINED 4,哪個SQL使用的臨時表最多: SUM_CREATED_TMP_DISK_TABLES、SUM_CREATED_TMP_TABLES 5,哪個SQL返回的結(jié)果集最多: SUM_ROWS_SENT 6,哪個SQL排序數(shù)最多: SUM_SORT_ROWS 通過上述指標我們可以間接獲得某類SQL的邏輯IO(SUM_ROWS_EXAMINED),CPU消耗(SUM_SORT_ROWS),網(wǎng)絡(luò)帶寬(SUM_ROWS_SENT)的對比。 通過file_summary_by_instance表,可以獲得系統(tǒng)運行到現(xiàn)在,哪個文件(表)物理IO最多,這可能意味著這個表經(jīng)常需要訪問磁盤IO。 7,哪個表、文件邏輯IO最多(熱數(shù)據(jù)): zjy@performance_schema 12:16:18>SELECT FILE_NAME,EVENT_NAME,COUNT_READ,SUM_NUMBER_OF_BYTES_READ,COUNT_WRITE,SUM_NUMBER_OF_BYTES_WRITE FROM file_summary_by_instance ORDER BY SUM_NUMBER_OF_BYTES_READ+SUM_NUMBER_OF_BYTES_WRITE DESC LIMIT 2\G *************************** 1. row *************************** FILE_NAME: /var/lib/mysql/ibdata1 #文件 EVENT_NAME: wait/io/file/innodb/innodb_data_file COUNT_READ: 544 SUM_NUMBER_OF_BYTES_READ: 10977280 COUNT_WRITE: 3700729 SUM_NUMBER_OF_BYTES_WRITE: 1433734217728 *************************** 2. row *************************** FILE_NAME: /var/lib/mysql/dchat/fans.ibd #表 EVENT_NAME: wait/io/file/innodb/innodb_data_file COUNT_READ: 9370680 SUM_NUMBER_OF_BYTES_READ: 153529188352 COUNT_WRITE: 67576376 SUM_NUMBER_OF_BYTES_WRITE: 1107815432192 8,哪個索引使用最多: zjy@performance_schema 12:18:42>SELECT OBJECT_NAME, INDEX_NAME, COUNT_FETCH, COUNT_INSERT, COUNT_UPDATE, COUNT_DELETE FROM table_io_waits_summary_by_index_usage ORDER BY SUM_TIMER_WAIT DESC limit 1; +-------------+------------+-------------+--------------+--------------+--------------+ | OBJECT_NAME | INDEX_NAME | COUNT_FETCH | COUNT_INSERT | COUNT_UPDATE | COUNT_DELETE | +-------------+------------+-------------+--------------+--------------+--------------+ | fans | PRIMARY | 29002695158 | 0 | 296373434 | 0 | +-------------+------------+-------------+--------------+--------------+--------------+ 1 row in set (0.29 sec) 通過table_io_waits_summary_by_index_usage表,可以獲得系統(tǒng)運行到現(xiàn)在,哪個表的具體哪個索引(包括主鍵索引,二級索引)使用最多。 9,哪個索引沒有使用過: zjy@performance_schema 12:23:22>SELECT OBJECT_SCHEMA, OBJECT_NAME, INDEX_NAME FROM table_io_waits_summary_by_index_usage WHERE INDEX_NAME IS NOT NULL AND COUNT_STAR = 0 AND OBJECT_SCHEMA <> 'mysql' ORDER BY OBJECT_SCHEMA,OBJECT_NAME; 10,哪個等待事件消耗的時間最多: zjy@performance_schema 12:25:22>SELECT EVENT_NAME, COUNT_STAR, SUM_TIMER_WAIT, AVG_TIMER_WAIT FROM events_waits_summary_global_by_event_name WHERE event_name != 'idle' ORDER BY SUM_TIMER_WAIT DESC LIMIT 1; 11,類似profiling功能: 分析具體某條SQL,該SQL在執(zhí)行各個階段的時間消耗,通過events_statements_xxx表和events_stages_xxx表,就可以達到目的。兩個表通過event_id與nesting_event_id關(guān)聯(lián),stages表的nesting_event_id為對應(yīng)statements表的event_id;針對每個stage可能出現(xiàn)的鎖等待,一個stage會對應(yīng)一個或多個wait,通過stage_xxx表的event_id字段與waits_xxx表的nesting_event_id進行關(guān)聯(lián)。如: 比如分析包含count(*)的某條SQL語句,具體如下: SELECT EVENT_ID, sql_text FROM events_statements_history WHERE sql_text LIKE '%count(*)%'; +----------+--------------------------------------+ | EVENT_ID | sql_text | +----------+--------------------------------------+ | 1690 | select count(*) from chuck.test_slow | +----------+--------------------------------------+ 首先得到了語句的event_id為1690,通過查找events_stages_xxx中nesting_event_id為1690的記錄,可以達到目的。 a.查看每個階段的時間消耗: SELECT event_id, EVENT_NAME, SOURCE, TIMER_END - TIMER_START FROM events_stages_history_long WHERE NESTING_EVENT_ID = 1690; +----------+--------------------------------+----------------------+-----------------------+ | event_id | EVENT_NAME | SOURCE | TIMER_END-TIMER_START | +----------+--------------------------------+----------------------+-----------------------+ | 1691 | stage/sql/init | mysqld.cc:990 | 316945000 | | 1693 | stage/sql/checking permissions | sql_parse.cc:5776 | 26774000 | | 1695 | stage/sql/Opening tables | sql_base.cc:4970 | 41436934000 | | 2638 | stage/sql/init | sql_select.cc:1050 | 85757000 | | 2639 | stage/sql/System lock | lock.cc:303 | 40017000 | | 2643 | stage/sql/optimizing | sql_optimizer.cc:138 | 38562000 | | 2644 | stage/sql/statistics | sql_optimizer.cc:362 | 52845000 | | 2645 | stage/sql/preparing | sql_optimizer.cc:485 | 53196000 | | 2646 | stage/sql/executing | sql_executor.cc:112 | 3153000 | | 2647 | stage/sql/Sending data | sql_executor.cc:192 | 7369072089000 | | 4304138 | stage/sql/end | sql_select.cc:1105 | 19920000 | | 4304139 | stage/sql/query end | sql_parse.cc:5463 | 44721000 | | 4304145 | stage/sql/closing tables | sql_parse.cc:5524 | 61723000 | | 4304152 | stage/sql/freeing items | sql_parse.cc:6838 | 455678000 | | 4304155 | stage/sql/logging slow query | sql_parse.cc:2258 | 83348000 | | 4304159 | stage/sql/cleaning up | sql_parse.cc:2163 | 4433000 | +----------+--------------------------------+----------------------+-----------------------+ 通過間接關(guān)聯(lián),我們能分析得到SQL語句在每個階段的時間消耗,時間單位以皮秒表示。這里展示的結(jié)果很類似profiling功能,有了performance schema,就不再需要profiling這個功能了。另外需要注意的是,由于默認情況下events_stages_history表中只為每個連接記錄了最近10條記錄,為了確保獲取所有記錄,需要訪問events_stages_history_long表 b.查看某個階段的鎖等待情況 針對每個stage可能出現(xiàn)的鎖等待,一個stage會對應(yīng)一個或多個wait,events_waits_history_long這個表容易爆滿[默認閥值10000]。由于select count(*)需要IO(邏輯IO或者物理IO),所以在stage/sql/Sending data階段會有io等待的統(tǒng)計。通過stage_xxx表的event_id字段與waits_xxx表的nesting_event_id進行關(guān)聯(lián)。 SELECT event_id, event_name, source, timer_wait, object_name, index_name, operation, nesting_event_id FROM events_waits_history_long WHERE nesting_event_id = 2647; +----------+---------------------------+-----------------+------------+-------------+------------+-----------+------------------+ | event_id | event_name | source | timer_wait | object_name | index_name | operation | nesting_event_id | +----------+---------------------------+-----------------+------------+-------------+------------+-----------+------------------+ | 190607 | wait/io/table/sql/handler | handler.cc:2842 | 1845888 | test_slow | idx_c1 | fetch | 2647 | | 190608 | wait/io/table/sql/handler | handler.cc:2842 | 1955328 | test_slow | idx_c1 | fetch | 2647 | | 190609 | wait/io/table/sql/handler | handler.cc:2842 | 1929792 | test_slow | idx_c1 | fetch | 2647 | | 190610 | wait/io/table/sql/handler | handler.cc:2842 | 1869600 | test_slow | idx_c1 | fetch | 2647 | | 190611 | wait/io/table/sql/handler | handler.cc:2842 | 1922496 | test_slow | idx_c1 | fetch | 2647 | +----------+---------------------------+-----------------+------------+-------------+------------+-----------+------------------+ 通過上面的實驗,我們知道了statement,stage,wait的三級結(jié)構(gòu),通過nesting_event_id進行關(guān)聯(lián),它表示某個事件的父event_id。 (2).模擬innodb行鎖等待的例子 會話A執(zhí)行語句update test_icp set y=y+1 where x=1(x為primary key),不commit;會話B執(zhí)行同樣的語句update test_icp set y=y+1 where x=1,會話B堵塞,并最終報錯。通過連接連接查詢events_statements_history_long和events_stages_history_long,可以看到在updating階段花了大約60s的時間。這主要因為實例上的innodb_lock_wait_timeout設(shè)置為60,等待60s后超時報錯了。 SELECT statement.EVENT_ID, stages.event_id, statement.sql_text, stages.event_name, stages.timer_wait FROM events_statements_history_long statement join events_stages_history_long stages on statement.event_id=stages.nesting_event_id WHERE statement.sql_text = 'update test_icp set y=y+1 where x=1'; +----------+----------+-------------------------------------+--------------------------------+----------------+ | EVENT_ID | event_id | sql_text | event_name | timer_wait | +----------+----------+-------------------------------------+--------------------------------+----------------+ | 5816 | 5817 | update test_icp set y=y+1 where x=1 | stage/sql/init | 195543000 | | 5816 | 5819 | update test_icp set y=y+1 where x=1 | stage/sql/checking permissions | 22730000 | | 5816 | 5821 | update test_icp set y=y+1 where x=1 | stage/sql/Opening tables | 66079000 | | 5816 | 5827 | update test_icp set y=y+1 where x=1 | stage/sql/init | 89116000 | | 5816 | 5828 | update test_icp set y=y+1 where x=1 | stage/sql/System lock | 218744000 | | 5816 | 5832 | update test_icp set y=y+1 where x=1 | stage/sql/updating | 6001362045000 | | 5816 | 5968 | update test_icp set y=y+1 where x=1 | stage/sql/end | 10435000 | | 5816 | 5969 | update test_icp set y=y+1 where x=1 | stage/sql/query end | 85979000 | | 5816 | 5983 | update test_icp set y=y+1 where x=1 | stage/sql/closing tables | 56562000 | | 5816 | 5990 | update test_icp set y=y+1 where x=1 | stage/sql/freeing items | 83563000 | | 5816 | 5992 | update test_icp set y=y+1 where x=1 | stage/sql/cleaning up | 4589000 | +----------+----------+-------------------------------------+--------------------------------+----------------+ 查看wait事件: SELECT event_id, event_name, source, timer_wait, object_name, index_name, operation, nesting_event_id FROM events_waits_history_long WHERE nesting_event_id = 5832; *************************** 1. row *************************** event_id: 5832 event_name: wait/io/table/sql/handler source: handler.cc:2782 timer_wait: 6005946156624 object_name: test_icp index_name: PRIMARY operation: fetch 從結(jié)果來看,waits表中記錄了一個fetch等待事件,但并沒有更細的innodb行鎖等待事件統(tǒng)計。 (3).模擬MDL鎖等待的例子 會話A執(zhí)行一個大查詢select count(*) from test_slow,會話B執(zhí)行表結(jié)構(gòu)變更alter table test_slow modify c2 varchar(152);通過如下語句可以得到alter語句的執(zhí)行過程,重點關(guān)注“stage/sql/Waiting for table metadata lock”階段。 SELECT statement.EVENT_ID, stages.event_id, statement.sql_text, stages.event_name as stage_name, stages.timer_wait as stage_time FROM events_statements_history_long statement left join events_stages_history_long stages on statement.event_id=stages.nesting_event_id WHERE statement.sql_text = 'alter table test_slow modify c2 varchar(152)'; +-----------+-----------+----------------------------------------------+----------------------------------------------------+---------------+ | EVENT_ID | event_id | sql_text | stage_name | stage_time | +-----------+-----------+----------------------------------------------+----------------------------------------------------+---------------+ | 326526744 | 326526745 | alter table test_slow modify c2 varchar(152) | stage/sql/init | 216662000 | | 326526744 | 326526747 | alter table test_slow modify c2 varchar(152) | stage/sql/checking permissions | 18183000 | | 326526744 | 326526748 | alter table test_slow modify c2 varchar(152) | stage/sql/checking permissions | 10294000 | | 326526744 | 326526750 | alter table test_slow modify c2 varchar(152) | stage/sql/init | 4783000 | | 326526744 | 326526751 | alter table test_slow modify c2 varchar(152) | stage/sql/Opening tables | 140172000 | | 326526744 | 326526760 | alter table test_slow modify c2 varchar(152) | stage/sql/setup | 157643000 | | 326526744 | 326526769 | alter table test_slow modify c2 varchar(152) | stage/sql/creating table | 8723217000 | | 326526744 | 326526803 | alter table test_slow modify c2 varchar(152) | stage/sql/After create | 257332000 | | 326526744 | 326526832 | alter table test_slow modify c2 varchar(152) | stage/sql/Waiting for table metadata lock | 1000181831000 | | 326526744 | 326526835 | alter table test_slow modify c2 varchar(152) | stage/sql/After create | 33483000 | | 326526744 | 326526838 | alter table test_slow modify c2 varchar(152) | stage/sql/Waiting for table metadata lock | 1000091810000 | | 326526744 | 326526841 | alter table test_slow modify c2 varchar(152) | stage/sql/After create | 17187000 | | 326526744 | 326526844 | alter table test_slow modify c2 varchar(152) | stage/sql/Waiting for table metadata lock | 1000126464000 | | 326526744 | 326526847 | alter table test_slow modify c2 varchar(152) | stage/sql/After create | 27472000 | | 326526744 | 326526850 | alter table test_slow modify c2 varchar(152) | stage/sql/Waiting for table metadata lock | 561996133000 | | 326526744 | 326526853 | alter table test_slow modify c2 varchar(152) | stage/sql/After create | 124876000 | | 326526744 | 326526877 | alter table test_slow modify c2 varchar(152) | stage/sql/System lock | 30659000 | | 326526744 | 326526881 | alter table test_slow modify c2 varchar(152) | stage/sql/preparing for alter table | 40246000 | | 326526744 | 326526889 | alter table test_slow modify c2 varchar(152) | stage/sql/altering table | 36628000 | | 326526744 | 326528280 | alter table test_slow modify c2 varchar(152) | stage/sql/end | 43824000 | | 326526744 | 326528281 | alter table test_slow modify c2 varchar(152) | stage/sql/query end | 112557000 | | 326526744 | 326528299 | alter table test_slow modify c2 varchar(152) | stage/sql/closing tables | 27707000 | | 326526744 | 326528305 | alter table test_slow modify c2 varchar(152) | stage/sql/freeing items | 201614000 | | 326526744 | 326528308 | alter table test_slow modify c2 varchar(152) | stage/sql/cleaning up | 3584000 | +-----------+-----------+----------------------------------------------+----------------------------------------------------+---------------+ 從結(jié)果可以看到,出現(xiàn)了多次stage/sql/Waiting for table metadata lock階段,并且間隔1s,說明每隔1s鐘會重試判斷。找一個該階段的event_id,通過nesting_event_id關(guān)聯(lián),確定到底在等待哪個wait事件。 SELECT event_id, event_name, source, timer_wait, object_name, index_name, operation, nesting_event_id FROM events_waits_history_long WHERE nesting_event_id = 326526850; +-----------+---------------------------------------------------+------------------+--------------+-------------+------------+------------+------------------+ | event_id | event_name | source | timer_wait | object_name | index_name | operation | nesting_event_id | +-----------+---------------------------------------------------+------------------+--------------+-------------+------------+------------+------------------+ | 326526851 | wait/synch/cond/sql/MDL_context::COND_wait_status | mdl.cc:1327 | 562417991328 | NULL | NULL | timed_wait | 326526850 | | 326526852 | wait/synch/mutex/mysys/my_thread_var::mutex | sql_class.h:3481 | 733248 | NULL | NULL | lock | 326526850 | +-----------+---------------------------------------------------+------------------+--------------+-------------+------------+------------+------------------+ 通過結(jié)果可以知道,產(chǎn)生阻塞的是條件變量MDL_context::COND_wait_status,并且顯示了代碼的位置。 總結(jié): 本文通過對Performance Schema數(shù)據(jù)庫的介紹,主要用于收集數(shù)據(jù)庫服務(wù)器性能參數(shù):①提供進程等待的詳細信息,包括鎖、互斥變量、文件信息;②保存歷史的事件匯總信息,為提供MySQL服務(wù)器性能做出詳細的判斷;③對于新增和刪除監(jiān)控事件點都非常容易,并可以改變mysql服務(wù)器的監(jiān)控周期,例如(CYCLE、MICROSECOND)。通過該庫得到數(shù)據(jù)庫運行的統(tǒng)計信息,更好分析定位問題和完善監(jiān)控信息。類似的監(jiān)控還有: 打開標準的innodb監(jiān)控: CREATE TABLE innodb_monitor (a INT) ENGINE=INNODB; 打開innodb的鎖監(jiān)控: CREATE TABLE innodb_lock_monitor (a INT) ENGINE=INNODB; 打開innodb表空間監(jiān)控: CREATE TABLE innodb_tablespace_monitor (a INT) ENGINE=INNODB; 打開innodb表監(jiān)控: CREATE TABLE innodb_table_monitor (a INT) ENGINE=INNODB; 參考文章: https://dev./doc/refman/5.6/en/performance-schema.html http://www.cnblogs.com/cchust/p/5022148.html http://www.cnblogs.com/cchust/p/5057498.html http://www.cnblogs.com/cchust/p/5061131.html
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