Current Path : /home/usr.opt/mysql57/mysql-test/r/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
Current File : //home/usr.opt/mysql57/mysql-test/r/query_cache_debug.result |
flush status; set query_cache_type=DEMAND; Warnings: Warning 1287 '@@query_cache_type' is deprecated and will be removed in a future release. set global query_cache_size= 1024*768; Warnings: Warning 1287 '@@query_cache_size' is deprecated and will be removed in a future release. drop table if exists t1; create table t1 (a varchar(100)); insert into t1 values ('aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'),('bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb'); Activate debug hook and attempt to retrieve the statement from the cache. set debug_sync="wait_in_query_cache_insert SIGNAL parked WAIT_FOR go"; select SQL_CACHE * from t1;; set debug_sync="now WAIT_FOR parked"; On a second connection; clear the query cache. show status like 'Qcache_queries_in_cache'; Variable_name Value Qcache_queries_in_cache 1 set global query_cache_size= 0; Warnings: Warning 1287 '@@query_cache_size' is deprecated and will be removed in a future release. Signal the debug hook to release the lock. set debug_sync="now SIGNAL go"; Show query cache status. show status like 'Qcache_queries_in_cache'; Variable_name Value Qcache_queries_in_cache 0 a aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb Warnings: Warning 1681 'SQL_CACHE' is deprecated and will be removed in a future release. set debug_sync= 'RESET'; set global query_cache_size= 0; Warnings: Warning 1287 '@@query_cache_size' is deprecated and will be removed in a future release. use test; drop table t1; SET @old_concurrent_insert= @@GLOBAL.concurrent_insert; SET @old_query_cache_size= @@GLOBAL.query_cache_size; Warnings: Warning 1287 '@@query_cache_size' is deprecated and will be removed in a future release. DROP TABLE IF EXISTS t1, t2; CREATE TABLE t1 (a INT); CREATE TABLE t2 (a INT); INSERT INTO t1 VALUES (1),(2),(3); SET GLOBAL concurrent_insert= 1; SET GLOBAL query_cache_size= 1024*512; Warnings: Warning 1287 '@@query_cache_size' is deprecated and will be removed in a future release. SET GLOBAL query_cache_type= ON; Warnings: Warning 1287 '@@query_cache_type' is deprecated and will be removed in a future release. # Switch to connection con1 SET DEBUG_SYNC = "wait_after_query_cache_invalidate SIGNAL parked WAIT_FOR go"; # Send concurrent insert, will wait in the query cache table invalidate INSERT INTO t1 VALUES (4); # Switch to connection default # Wait for concurrent insert to reach the debug point SET DEBUG_SYNC = "now WAIT_FOR parked"; # Switch to connection con2 # Send SELECT that shouldn't be cached SELECT * FROM t1; a 1 2 3 # Switch to connection default # Notify the concurrent insert to proceed SET DEBUG_SYNC = "now SIGNAL go"; # Switch to connection con1 # Gather insert result SHOW STATUS LIKE "Qcache_queries_in_cache"; Variable_name Value Qcache_queries_in_cache 0 # Test that it's cacheable SELECT * FROM t1; a 1 2 3 4 SHOW STATUS LIKE "Qcache_queries_in_cache"; Variable_name Value Qcache_queries_in_cache 1 # Disconnect # Restore defaults SET DEBUG_SYNC= 'RESET'; RESET QUERY CACHE; Warnings: Warning 1681 'RESET QUERY CACHE' is deprecated and will be removed in a future release. DROP TABLE t1,t2; SET GLOBAL concurrent_insert= DEFAULT; SET GLOBAL query_cache_size= DEFAULT; Warnings: Warning 1287 '@@query_cache_size' is deprecated and will be removed in a future release. SET GLOBAL query_cache_type= DEFAULT; Warnings: Warning 1287 '@@query_cache_type' is deprecated and will be removed in a future release. # # Bug43758 Query cache can lock up threads in 'freeing items' state # FLUSH STATUS; SET GLOBAL query_cache_type=DEMAND; Warnings: Warning 1287 '@@query_cache_type' is deprecated and will be removed in a future release. SET GLOBAL query_cache_size= 1024*768; Warnings: Warning 1287 '@@query_cache_size' is deprecated and will be removed in a future release. DROP TABLE IF EXISTS t1,t2,t3,t4,t5; CREATE TABLE t1 (a VARCHAR(100)); CREATE TABLE t2 (a VARCHAR(100)); CREATE TABLE t3 (a VARCHAR(100)); CREATE TABLE t4 (a VARCHAR(100)); CREATE TABLE t5 (a VARCHAR(100)); INSERT INTO t1 VALUES ('aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'),('bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb'); INSERT INTO t2 VALUES ('aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'),('bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb'); INSERT INTO t3 VALUES ('aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'),('bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb'); INSERT INTO t4 VALUES ('aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'),('bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb'); INSERT INTO t5 VALUES ('aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'),('bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb'); =================================== Connection thd1 ** ** Load Query Cache with a result set and one table. ** SELECT SQL_CACHE * FROM t1; a aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb Warnings: Warning 1681 'SQL_CACHE' is deprecated and will be removed in a future release. ************************************************************************* ** We want to accomplish the following state: ** - Query cache status: TABLE_FLUSH_IN_PROGRESS ** - THD1: invalidate_table_internal (iterating query blocks) ** - THD2: query_cache_insert (cond_wait) ** - THD3: query_cache_insert (cond_wait) ** - No thread should be holding the structure_guard_mutex. ** ** First step is to place a DELETE-statement on the debug hook just ** before the mutex lock in invalidate_table_internal. ** This will allow new result sets to be written into the QC. ** SET DEBUG_SYNC="wait_in_query_cache_invalidate1 SIGNAL parked1_1 WAIT_FOR go1_1"; SET DEBUG_SYNC="wait_in_query_cache_invalidate2 SIGNAL parked1_2 WAIT_FOR go1_2"; DELETE FROM t1 WHERE a like '%a%';; =================================== Connection default ** Assert that the expect process status is obtained. SET DEBUG_SYNC="now WAIT_FOR parked1_1"; ** =================================== Connection thd2 ** On THD2: Insert a result into the cache. This attempt will be blocked ** because of a debug hook placed just before the mutex lock after which ** the first part of the result set is written. SET DEBUG_SYNC="wait_in_query_cache_insert SIGNAL parked2 WAIT_FOR go2 EXECUTE 1"; SELECT SQL_CACHE * FROM t2 UNION SELECT * FROM t3; =================================== Connection default ** Assert that the SELECT-stmt thread reaches the sync point. SET DEBUG_SYNC="now WAIT_FOR parked2"; ** ** =================================== Connection thd3 ** On THD3: Insert another result into the cache and block on the same ** debug hook. SET DEBUG_SYNC="wait_in_query_cache_insert SIGNAL parked3 WAIT_FOR go3 EXECUTE 1"; SELECT SQL_CACHE * FROM t4 UNION SELECT * FROM t5; =================================== Connection default ** Assert that the SELECT-stmt thread reaches the sync point. SET DEBUG_SYNC="now WAIT_FOR parked3"; ** ** ** Signal the DELETE thread, THD1, to continue. It will enter the mutex ** lock and set query cache status to TABLE_FLUSH_IN_PROGRESS and then ** unlock the mutex before stopping on the next debug hook. SET DEBUG_SYNC="now SIGNAL go1_1"; ** Assert that we reach the next debug hook. SET DEBUG_SYNC="now WAIT_FOR parked1_2"; ** ** Signal the remaining debug hooks blocking THD2 and THD3. ** The threads will grab the guard mutex enter the wait condition and ** and finally release the mutex. The threads will continue to wait ** until a broadcast signal reaches them causing both threads to ** come alive and check the condition. SET DEBUG_SYNC="now SIGNAL go2"; ** Wait for thd2 to receive the signal SET DEBUG_SYNC="now SIGNAL go3"; ** Wait for thd3 to receive the signal ** ** Finally signal the DELETE statement on THD1 one last time. ** The stmt will complete the query cache invalidation and return ** cache status to NO_FLUSH_IN_PROGRESS. On the status change ** One signal will be sent to the thread group waiting for executing ** invalidations and a broadcast signal will be sent to the thread ** group holding result set writers. SET DEBUG_SYNC="now SIGNAL go1_2"; ** ************************************************************************* ** No tables should be locked =================================== Connection thd2 a aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb Warnings: Warning 1681 'SQL_CACHE' is deprecated and will be removed in a future release. DELETE FROM t1; DELETE FROM t2; DELETE FROM t3; =================================== Connection thd3 a aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb Warnings: Warning 1681 'SQL_CACHE' is deprecated and will be removed in a future release. DELETE FROM t4; DELETE FROM t5; =================================== Connection thd1 ** Done. SET DEBUG_SYNC= 'RESET'; SET GLOBAL query_cache_size= 0; Warnings: Warning 1287 '@@query_cache_size' is deprecated and will be removed in a future release. # Restore defaults RESET QUERY CACHE; Warnings: Warning 1681 'RESET QUERY CACHE' is deprecated and will be removed in a future release. FLUSH STATUS; DROP TABLE t1,t2,t3,t4,t5; SET GLOBAL query_cache_size= DEFAULT; Warnings: Warning 1287 '@@query_cache_size' is deprecated and will be removed in a future release. SET GLOBAL query_cache_type= DEFAULT; Warnings: Warning 1287 '@@query_cache_type' is deprecated and will be removed in a future release. # # Bug#56822: Add a thread state for sessions waiting on the query cache lock # SET @old_query_cache_size= @@GLOBAL.query_cache_size; Warnings: Warning 1287 '@@query_cache_size' is deprecated and will be removed in a future release. DROP TABLE IF EXISTS t1; CREATE TABLE t1 (a INT); INSERT INTO t1 VALUES (1),(2),(3); SET GLOBAL concurrent_insert= 1; SET GLOBAL query_cache_size= 1024*512; Warnings: Warning 1287 '@@query_cache_size' is deprecated and will be removed in a future release. SET GLOBAL query_cache_type= ON; Warnings: Warning 1287 '@@query_cache_type' is deprecated and will be removed in a future release. # Switch to connection con1 SET DEBUG_SYNC = "wait_in_query_cache_invalidate2 SIGNAL parked WAIT_FOR go"; # Send INSERT, will wait in the query cache table invalidation INSERT INTO t1 VALUES (4);; # Switch to connection default # Wait for insert to reach the debug point SET DEBUG_SYNC = "now WAIT_FOR parked"; # Switch to connection con2 # Send a query that should wait on the query cache lock RESET QUERY CACHE; # Switch to connection default # Wait for the state to be reflected in the processlist # Signal that the query cache can be unlocked SET DEBUG_SYNC="now SIGNAL go"; # Reap con1 and disconnect # Reap con2 and disconnect Warnings: Warning 1681 'RESET QUERY CACHE' is deprecated and will be removed in a future release. # Restore defaults SET DEBUG_SYNC= 'RESET'; RESET QUERY CACHE; Warnings: Warning 1681 'RESET QUERY CACHE' is deprecated and will be removed in a future release. DROP TABLE t1; SET GLOBAL query_cache_size= DEFAULT; Warnings: Warning 1287 '@@query_cache_size' is deprecated and will be removed in a future release.