PostgreSQL 鎖等待跟蹤

摘要PostgreSQL 在打印LONG SQL時，鎖等待的時間也會算在內，並且目前在日誌中沒有將鎖等待的時間單獨打印出來。 shared_preload_libraries='auto_explain' auto_explain.log_min_duration='1s' auto_explai...

PostgreSQL 在打印LONG SQL時，鎖等待的時間也會算在內，並且目前在日誌中沒有將鎖等待的時間單獨打印出來。

shared_preload_libraries='auto_explain'
auto_explain.log_min_duration='1s'
auto_explain.log_analyze=true
auto_explain.log_buffers=true
auto_explain.log_timing=true
auto_explain.log_triggers=true
auto_explain.log_verbose=true
auto_explain.log_nested_statements=true

pg_ctl restart -m fast

例子:

session A:
postgres=# create table test2(id int, info text);
CREATE TABLE
postgres=# insert into test2 values (1,'test');
INSERT 0 1
postgres=# begin;
BEGIN
postgres=# update test2 set info='a' where id=1;
UPDATE 1

session B:
postgres=# update test2 set info='b' ;
wait

session A:
postgres=# end;
COMMIT

session B:
UPDATE 1

查看日誌如下：

2016-03-15 15:44:23.618 CST,"postgres","postgres",106815,"[local]",56e7bc6c.1a13f,3,"UPDATE",2016-03-15 15:40:28 CST,3/12,574614687,LOG,00000,"duration: 32038.420 ms  plan:
Query Text: update test2 set info='b' ;
Update on test2  (cost=0.00..22.70 rows=1270 width=10) (actual time=32038.418..32038.418 rows=0 loops=1)
  Buffers: shared hit=5
  ->  Seq Scan on test2  (cost=0.00..22.70 rows=1270 width=10) (actual time=0.014..0.015 rows=1 loops=1)
        Buffers: shared hit=1",,,,,,,,"explain_ExecutorEnd, auto_explain.c:333","psql"
2016-03-15 15:44:23.618 CST,"postgres","postgres",106815,"[local]",56e7bc6c.1a13f,4,"UPDATE",2016-03-15 15:40:28 CST,3/0,0,LOG,00000,"duration: 32039.289 ms  statement: update test2 set info='b' ;",,,,,,,,"exec_simple_query, postgres.c:1181","psql"

等待時間也被計算在內了。

如果要分析鎖等待的話，最好加上如下參數：

log_lock_waits = on
deadlock_timeout = 1s

那麼在日誌中，可以看到會話等待鎖的時間超過deadlock_timeout時，會打印一條日誌，告訴你在等待那個PID，等待什麼鎖：

2016-03-15 16:30:57.129 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,32,"UPDATE waiting",2016-03-15 16:12:15 CST,3/17,574614691,LOG,00000,"process 10220 still waiting for ShareLock on transaction 574614690 after 1000.036 ms","Process holding the lock: 9725. Wait queue: 10220.",,,,"while updating tuple (0,5) in relation ""test2""","update test2 set info='b' ;",,"ProcSleep, proc.c:1323","psql"

在獲取到鎖之後，又會打印一條日誌：

2016-03-15 16:32:36.323 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,33,"UPDATE waiting",2016-03-15 16:12:15 CST,3/17,574614691,LOG,00000,"process 10220 acquired ShareLock on transaction 574614690 after 100194.020 ms",,,,,"while updating tuple (0,5) in relation ""test2""","update test2 set info='b' ;",,"ProcSleep, proc.c:1327","psql"

分析以上兩條日誌，和long sql的日誌關聯起來，就可以知道LONG SQL的鎖等待花了多少時間。

如果要跟蹤更詳細的鎖信息，需要修改一下頭文件，重新編譯：

vi src/include/pg_config_manual.h
#define LOCK_DEBUG

make clean
make distclean
configure again
make -j 32
make install -j 32

vi $PGDATA/postgresql.conf
trace_locks = true

pg_ctl restart -m fast

以上CASE，可以跟蹤到如下鎖信息：

2016-03-15 16:12:08.389 CST,,,9725,"",56e7c3d8.25fd,1,"",2016-03-15 16:12:08 CST,,0,LOG,00000,"connection received: host=[local]",,,,,,,,"BackendInitialize, postmaster.c:4081",""
2016-03-15 16:12:08.390 CST,"postgres","postgres",9725,"[local]",56e7c3d8.25fd,2,"authentication",2016-03-15 16:12:08 CST,2/11,0,LOG,00000,"connection authorized: user=postgres database=postgres",,,,,,,,"PerformAuthentication, postinit.c:259",""
2016-03-15 16:12:08.391 CST,"postgres","postgres",9725,"[local]",56e7c3d8.25fd,3,"startup",2016-03-15 16:12:08 CST,2/0,0,LOG,00000,"LockReleaseAll: lockmethod=1",,,,,,,,"LockReleaseAll, lock.c:1951","psql"
2016-03-15 16:12:08.391 CST,"postgres","postgres",9725,"[local]",56e7c3d8.25fd,4,"startup",2016-03-15 16:12:08 CST,2/0,0,LOG,00000,"LockReleaseAll done",,,,,,,,"LockReleaseAll, lock.c:2198","psql"
2016-03-15 16:12:13.968 CST,"postgres","postgres",9725,"[local]",56e7c3d8.25fd,5,"UPDATE",2016-03-15 16:12:08 CST,2/12,0,LOG,00000,"LockAcquire: lock [13241,53029] RowExclusiveLock",,,,,,"update test2 set info='a' where id=1;",8,"LockAcquireExtended, lock.c:724","psql"
2016-03-15 16:12:13.969 CST,"postgres","postgres",9725,"[local]",56e7c3d8.25fd,6,"UPDATE",2016-03-15 16:12:08 CST,2/12,0,LOG,00000,"LockAcquire: lock [13241,53029] RowExclusiveLock",,,,,,"update test2 set info='a' where id=1;",,"LockAcquireExtended, lock.c:724","psql"
2016-03-15 16:12:15.815 CST,,,10220,"",56e7c3df.27ec,1,"",2016-03-15 16:12:15 CST,,0,LOG,00000,"connection received: host=[local]",,,,,,,,"BackendInitialize, postmaster.c:4081",""
2016-03-15 16:12:15.816 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,2,"authentication",2016-03-15 16:12:15 CST,3/15,0,LOG,00000,"connection authorized: user=postgres database=postgres",,,,,,,,"PerformAuthentication, postinit.c:259",""
2016-03-15 16:12:15.817 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,3,"startup",2016-03-15 16:12:15 CST,3/0,0,LOG,00000,"LockReleaseAll: lockmethod=1",,,,,,,,"LockReleaseAll, lock.c:1951","psql"
2016-03-15 16:12:15.817 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,4,"startup",2016-03-15 16:12:15 CST,3/0,0,LOG,00000,"LockReleaseAll done",,,,,,,,"LockReleaseAll, lock.c:2198","psql"
2016-03-15 16:12:16.777 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,5,"UPDATE",2016-03-15 16:12:15 CST,3/16,0,LOG,00000,"LockAcquire: lock [13241,53029] RowExclusiveLock",,,,,,"update test2 set info='b' ;",8,"LockAcquireExtended, lock.c:724","psql"
2016-03-15 16:12:16.778 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,6,"UPDATE",2016-03-15 16:12:15 CST,3/16,0,LOG,00000,"LockAcquire: lock [13241,53029] RowExclusiveLock",,,,,,"update test2 set info='b' ;",,"LockAcquireExtended, lock.c:724","psql"
2016-03-15 16:12:16.778 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,7,"UPDATE",2016-03-15 16:12:15 CST,3/16,574614689,LOG,00000,"LockAcquire: lock [13241,53029] ExclusiveLock",,,,,,"update test2 set info='b' ;",,"LockAcquireExtended, lock.c:724","psql"
2016-03-15 16:12:16.778 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,8,"UPDATE",2016-03-15 16:12:15 CST,3/16,574614689,LOG,00000,"LockAcquire: new: lock(0x7f88ead65ed8) id(13241,53029,0,3,3,1) grantMask(0) req(0,0,0,0,0,0,0)=0 grant(0,0,0,0,0,0,0)=0 wait(0) type(ExclusiveLock)",,,,,,"update test2 set info='b' ;",,"LOCK_PRINT, lock.c:319","psql"
2016-03-15 16:12:16.778 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,9,"UPDATE",2016-03-15 16:12:15 CST,3/16,574614689,LOG,00000,"LockAcquire: new: proclock(0x7f88eadf4878) lock(0x7f88ead65ed8) method(1) proc(0x7f88eb0211f0) hold(0)",,,,,,"update test2 set info='b' ;",,"PROCLOCK_PRINT, lock.c:331","psql"
2016-03-15 16:12:16.778 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,10,"UPDATE",2016-03-15 16:12:15 CST,3/16,574614689,LOG,00000,"LockCheckConflicts: no conflict: proclock(0x7f88eadf4878) lock(0x7f88ead65ed8) method(1) proc(0x7f88eb0211f0) hold(0)",,,,,,"update test2 set info='b' ;",,"PROCLOCK_PRINT, lock.c:331","psql"
2016-03-15 16:12:16.778 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,11,"UPDATE",2016-03-15 16:12:15 CST,3/16,574614689,LOG,00000,"GrantLock: lock(0x7f88ead65ed8) id(13241,53029,0,3,3,1) grantMask(80) req(0,0,0,0,0,0,1)=1 grant(0,0,0,0,0,0,1)=1 wait(0) type(ExclusiveLock)",,,,,,"update test2 set info='b' ;",,"LOCK_PRINT, lock.c:319","psql"
2016-03-15 16:17:05.528 CST,"postgres","postgres",9725,"[local]",56e7c3d8.25fd,7,"COMMIT",2016-03-15 16:12:08 CST,2/0,574614688,LOG,00000,"LockReleaseAll: lockmethod=1",,,,,,"end;",,"LockReleaseAll, lock.c:1951","psql"
2016-03-15 16:17:05.528 CST,"postgres","postgres",9725,"[local]",56e7c3d8.25fd,8,"COMMIT",2016-03-15 16:12:08 CST,2/0,574614688,LOG,00000,"LockReleaseAll done",,,,,,"end;",,"LockReleaseAll, lock.c:2198","psql"
2016-03-15 16:17:05.528 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,12,"UPDATE",2016-03-15 16:12:15 CST,3/16,574614689,LOG,00000,"LockRelease: lock [13241,53029] ExclusiveLock",,,,,,"update test2 set info='b' ;",,"LockRelease, lock.c:1758","psql"
2016-03-15 16:17:05.528 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,13,"UPDATE",2016-03-15 16:12:15 CST,3/16,574614689,LOG,00000,"LockRelease: found: lock(0x7f88ead65ed8) id(13241,53029,0,3,3,1) grantMask(80) req(0,0,0,0,0,0,1)=1 grant(0,0,0,0,0,0,1)=1 wait(0) type(ExclusiveLock)",,,,,,"update test2 set info='b' ;",,"LOCK_PRINT, lock.c:319","psql"
2016-03-15 16:17:05.528 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,14,"UPDATE",2016-03-15 16:12:15 CST,3/16,574614689,LOG,00000,"LockRelease: found: proclock(0x7f88eadf4878) lock(0x7f88ead65ed8) method(1) proc(0x7f88eb0211f0) hold(80)",,,,,,"update test2 set info='b' ;",,"PROCLOCK_PRINT, lock.c:331","psql"
2016-03-15 16:17:05.528 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,15,"UPDATE",2016-03-15 16:12:15 CST,3/16,574614689,LOG,00000,"UnGrantLock: updated: lock(0x7f88ead65ed8) id(13241,53029,0,3,3,1) grantMask(0) req(0,0,0,0,0,0,0)=0 grant(0,0,0,0,0,0,0)=0 wait(0) type(ExclusiveLock)",,,,,,"update test2 set info='b' ;",,"LOCK_PRINT, lock.c:319","psql"
2016-03-15 16:17:05.528 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,16,"UPDATE",2016-03-15 16:12:15 CST,3/16,574614689,LOG,00000,"UnGrantLock: updated: proclock(0x7f88eadf4878) lock(0x7f88ead65ed8) method(1) proc(0x7f88eb0211f0) hold(0)",,,,,,"update test2 set info='b' ;",,"PROCLOCK_PRINT, lock.c:331","psql"
2016-03-15 16:17:05.528 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,17,"UPDATE",2016-03-15 16:12:15 CST,3/16,574614689,LOG,00000,"CleanUpLock: deleting: proclock(0x7f88eadf4878) lock(0x7f88ead65ed8) method(1) proc(0x7f88eb0211f0) hold(0)",,,,,,"update test2 set info='b' ;",,"PROCLOCK_PRINT, lock.c:331","psql"
2016-03-15 16:17:05.528 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,18,"UPDATE",2016-03-15 16:12:15 CST,3/16,574614689,LOG,00000,"CleanUpLock: deleting: lock(0x7f88ead65ed8) id(13241,53029,0,3,3,1) grantMask(0) req(0,0,0,0,0,0,0)=0 grant(0,0,0,0,0,0,0)=0 wait(0) type(INVALID)",,,,,,"update test2 set info='b' ;",,"LOCK_PRINT, lock.c:319","psql"
2016-03-15 16:17:05.528 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,19,"UPDATE",2016-03-15 16:12:15 CST,3/16,574614689,LOG,00000,"LockAcquire: lock [13241,53029] AccessShareLock",,,,,,"update test2 set info='b' ;",,"LockAcquireExtended, lock.c:724","psql"
2016-03-15 16:17:05.528 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,20,"UPDATE",2016-03-15 16:12:15 CST,3/16,574614689,LOG,00000,"LockRelease: lock [13241,53029] AccessShareLock",,,,,,"update test2 set info='b' ;",,"LockRelease, lock.c:1758","psql"
2016-03-15 16:17:05.528 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,21,"UPDATE",2016-03-15 16:12:15 CST,3/16,574614689,LOG,00000,"duration: 288750.628 ms  plan:
Query Text: update test2 set info='b' ;
Update on test2  (cost=0.00..22.70 rows=1270 width=10) (actual time=288750.624..288750.624 rows=0 loops=1)
  Buffers: shared hit=5
  ->  Seq Scan on test2  (cost=0.00..22.70 rows=1270 width=10) (actual time=0.013..0.015 rows=1 loops=1)
        Buffers: shared hit=1",,,,,,,,"explain_ExecutorEnd, auto_explain.c:333","psql"
2016-03-15 16:17:05.529 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,22,"UPDATE",2016-03-15 16:12:15 CST,3/0,574614689,LOG,00000,"LockReleaseAll: lockmethod=1",,,,,,"update test2 set info='b' ;",,"LockReleaseAll, lock.c:1951","psql"
2016-03-15 16:17:05.529 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,23,"UPDATE",2016-03-15 16:12:15 CST,3/0,574614689,LOG,00000,"LockReleaseAll done",,,,,,"update test2 set info='b' ;",,"LockReleaseAll, lock.c:2198","psql"
2016-03-15 16:17:05.529 CST,"postgres","postgres",10220,"[local]",56e7c3df.27ec,24,"UPDATE",2016-03-15 16:12:15 CST,3/0,0,LOG,00000,"duration: 288751.635 ms  statement: update test2 set info='b' ;",,,,,,,,"exec_simple_query, postgres.c:1181","psql"

鎖的解釋需要對照src/include/storage/lock.h

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