CREATE TABLE t1 (a INT PRIMARY KEY, b TEXT) ENGINE=InnoDB; CREATE TABLE t2 (a INT PRIMARY KEY) ENGINE=InnoDB; CREATE TABLE t3 (a INT PRIMARY KEY, b TEXT, c TEXT) ENGINE=InnoDB; INSERT INTO t1 VALUES (1,REPEAT('a',30000)),(2,REPEAT('b',40000)); SET DEBUG_SYNC='before_row_upd_extern SIGNAL have_latch WAIT_FOR go1'; BEGIN; UPDATE t1 SET a=a+2; ROLLBACK; BEGIN; UPDATE t1 SET b=CONCAT(b,'foo'); SET DEBUG_SYNC='now WAIT_FOR have_latch'; SELECT a, RIGHT(b,20) FROM t1; SET DEBUG_SYNC='now SIGNAL go1'; a RIGHT(b,20) 1 aaaaaaaaaaaaaaaaaaaa 2 bbbbbbbbbbbbbbbbbbbb SET DEBUG='+d,row_ins_extern_checkpoint'; SET DEBUG_SYNC='before_row_ins_extern_latch SIGNAL rec_not_blob WAIT_FOR crash'; ROLLBACK; BEGIN; INSERT INTO t1 VALUES (3,REPEAT('c',50000)); SET DEBUG_SYNC='now WAIT_FOR rec_not_blob'; SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED; SELECT @@tx_isolation; @@tx_isolation READ-UNCOMMITTED SELECT a, RIGHT(b,20) FROM t1; a RIGHT(b,20) 1 aaaaaaaaaaaaaaaaaaaa 2 bbbbbbbbbbbbbbbbbbbb SELECT a FROM t1; a 1 2 3 SET DEBUG='+d,crash_commit_before'; INSERT INTO t2 VALUES (42); ERROR HY000: Lost connection to MySQL server during query ERROR HY000: Lost connection to MySQL server during query CHECK TABLE t1; Table Op Msg_type Msg_text test.t1 check status OK INSERT INTO t3 VALUES (1,REPEAT('d',7000),REPEAT('e',100)), (2,REPEAT('g',7000),REPEAT('h',100)); SET DEBUG_SYNC='before_row_upd_extern SIGNAL have_latch WAIT_FOR go'; UPDATE t3 SET c=REPEAT('f',3000) WHERE a=1; SET DEBUG_SYNC='now WAIT_FOR have_latch'; SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED; SELECT @@tx_isolation; @@tx_isolation READ-UNCOMMITTED SELECT a, RIGHT(b,20), RIGHT(c,20) FROM t3; SET DEBUG_SYNC='now SIGNAL go'; a RIGHT(b,20) RIGHT(c,20) 1 dddddddddddddddddddd ffffffffffffffffffff 2 gggggggggggggggggggg hhhhhhhhhhhhhhhhhhhh CHECK TABLE t1,t2,t3; Table Op Msg_type Msg_text test.t1 check status OK test.t2 check status OK test.t3 check status OK BEGIN; INSERT INTO t2 VALUES (347); SET DEBUG='+d,row_upd_extern_checkpoint'; SET DEBUG_SYNC='before_row_upd_extern SIGNAL have_latch WAIT_FOR crash'; UPDATE t3 SET c=REPEAT('i',3000) WHERE a=2; SET DEBUG_SYNC='now WAIT_FOR have_latch'; SELECT info FROM information_schema.processlist WHERE state = 'debug sync point: before_row_upd_extern'; info UPDATE t3 SET c=REPEAT('i',3000) WHERE a=2 SET DEBUG='+d,crash_commit_before'; COMMIT; ERROR HY000: Lost connection to MySQL server during query ERROR HY000: Lost connection to MySQL server during query CHECK TABLE t1,t2,t3; Table Op Msg_type Msg_text test.t1 check status OK test.t2 check status OK test.t3 check status OK SELECT a, RIGHT(b,20), RIGHT(c,20) FROM t3; a RIGHT(b,20) RIGHT(c,20) 1 dddddddddddddddddddd ffffffffffffffffffff 2 gggggggggggggggggggg hhhhhhhhhhhhhhhhhhhh SELECT a FROM t3; a 1 2 BEGIN; INSERT INTO t2 VALUES (33101); SET DEBUG='+d,row_upd_extern_checkpoint'; SET DEBUG_SYNC='after_row_upd_extern SIGNAL have_latch WAIT_FOR crash'; UPDATE t3 SET c=REPEAT('j',3000) WHERE a=2; SET DEBUG_SYNC='now WAIT_FOR have_latch'; SELECT info FROM information_schema.processlist WHERE state = 'debug sync point: after_row_upd_extern'; info UPDATE t3 SET c=REPEAT('j',3000) WHERE a=2 SET DEBUG='+d,crash_commit_before'; COMMIT; ERROR HY000: Lost connection to MySQL server during query ERROR HY000: Lost connection to MySQL server during query CHECK TABLE t1,t2,t3; Table Op Msg_type Msg_text test.t1 check status OK test.t2 check status OK test.t3 check status OK SELECT a, RIGHT(b,20), RIGHT(c,20) FROM t3; a RIGHT(b,20) RIGHT(c,20) 1 dddddddddddddddddddd ffffffffffffffffffff 2 gggggggggggggggggggg hhhhhhhhhhhhhhhhhhhh SELECT a FROM t3; a 1 2 SELECT * FROM t2; a DROP TABLE t1,t2,t3;