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BUG#50038 Deadlock on flush logs with concurrent DML and RBR

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In auto-commit mode, updating both trx and non-trx tables (i.e. issuing a mixed
statement) causes the following sequence of events:

1 - "Flush trx changes" (MYSQL_BIN_LOG::write) - T1:
  1.1 - mutex_lock (&LOCK_log)
  1.2 - mutex_lock (&LOCK_prep_xids)
  1.3 - increase prepared_xids
  1.4 - mutex_unlock (&LOCK_prep_xids)
  1.5 - mutex_unlock (&LOCK_log)

2 - "Flush non-trx changes" (MYSQL_BIN_LOG::write) - T1:
  2.1 - mutex_lock (&LOCK_log)
  2.2 - mutex_unlock (&LOCK_log)

3. "unlog" - T1
  3.1 - mutex_lock (&LOCK_prep_xids)
  3.2 - decrease prepared xids
  3.3 - pthread_cond_signal(&COND_prep_xids);
  3.4 - mutex_unlock (&LOCK_prep_xids)

The "FLUSH logs" command produces the following sequence of events:

1 - "FLUSH logs" command (MYSQL_BIN_LOG::new_file_impl) - user thread:
  1.1 - mutex_lock (&LOCK_log)
  1.2 - mutex_lock (&LOCK_prep_xids)
  1.3 - while (prepared_xids)  pthread_cond_wait(..., &LOCK_prep_xids);
  1.4 - mutex_unlock (&LOCK_prep_xids)
  1.5 - mutex_unlock (&LOCK_log)

A deadlock will arise if T1 flushes the trx changes and thus increases
prepared_xids but before it is able to continue the execution and flush the
non-trx changes, an user thread calls the "FLUSH logs" command and wait that
the prepared_xids is decreased and gets to zero. However, T1 cannot proceed
with the call to "Flush non-trx changes" because it will block in the mutex
"LOCK_log" and by consequence cannot complete the execution and call the
unlog to decrease the prepared_xids.

To fix the problem, we ensure that the non-trx changes are always flushed
before the trx changes.

Note that if you call "Flush non-trx changes" and a concurrent "FLUSH logs" is
issued, the "Flush non-trx changes" may block, but a deadlock will never happen
because the prepared_xids will eventually get to zero. Bottom line, there will
not be any transaction able to increase the prepared_xids because they will
block in the mutex "LOCK_log" (MYSQL_BIN_LOG::write) and those that increased
the prepared_xids will eventually commit and decrease the prepared_xids.
This commit is contained in:
Alfranio Correia
2010-01-05 16:55:23 +00:00
parent f87816b450
commit 54b2371e92
7 changed files with 122 additions and 121 deletions
Download Patch File Download Diff File Expand all files Collapse all files

112
mysql-test/suite/rpl/r/rpl_mixed_mixing_engines.result
View File

@ -425,54 +425,60 @@ master-bin.000001 # Xid # # COMMIT /* XID */
UPDATE nt_3, tt_3 SET nt_3.info= "new text 25 --> 1", tt_3.info= "new text 25 --> 1" where nt_3.trans_id = tt_3.trans_id and tt_3.trans_id = 1;
Log_name Pos Event_type Server_id End_log_pos Info
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_3)
master-bin.000001 # Update_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.nt_3)
master-bin.000001 # Update_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Query # # COMMIT
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_3)
master-bin.000001 # Update_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
-e-e-e-e-e-e-e-e-e-e-e- >> NT << -e-e-e-e-e-e-e-e-e-e-e-
-b-b-b-b-b-b-b-b-b-b-b- >> NT << -b-b-b-b-b-b-b-b-b-b-b-
Log_name Pos Event_type Server_id End_log_pos Info
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_3)
master-bin.000001 # Update_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.nt_3)
master-bin.000001 # Update_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Query # # COMMIT
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_3)
master-bin.000001 # Update_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
-e-e-e-e-e-e-e-e-e-e-e- >> NT << -e-e-e-e-e-e-e-e-e-e-e-
-b-b-b-b-b-b-b-b-b-b-b- >> NT-trig << -b-b-b-b-b-b-b-b-b-b-b-
INSERT INTO nt_4(trans_id, stmt_id) VALUES (26, 1);
Log_name Pos Event_type Server_id End_log_pos Info
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_4)
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.nt_4)
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Query # # COMMIT
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_4)
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
-e-e-e-e-e-e-e-e-e-e-e- >> NT-trig << -e-e-e-e-e-e-e-e-e-e-e-
-b-b-b-b-b-b-b-b-b-b-b- >> NT-trig << -b-b-b-b-b-b-b-b-b-b-b-
Log_name Pos Event_type Server_id End_log_pos Info
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_4)
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.nt_4)
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Query # # COMMIT
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_4)
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
-e-e-e-e-e-e-e-e-e-e-e- >> NT-trig << -e-e-e-e-e-e-e-e-e-e-e-
-b-b-b-b-b-b-b-b-b-b-b- >> NT-func << -b-b-b-b-b-b-b-b-b-b-b-
INSERT INTO nt_5(trans_id, stmt_id, info) VALUES (27, 1, fc_i_tt_5_suc(27, 1));
Log_name Pos Event_type Server_id End_log_pos Info
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.nt_5)
master-bin.000001 # Table_map # # table_id: # (test.nt_6)
master-bin.000001 # Write_rows # # table_id: #
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Query # # COMMIT
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_5)
master-bin.000001 # Table_map # # table_id: # (test.tt_6)
master-bin.000001 # Write_rows # # table_id: #
@ -480,16 +486,16 @@ master-bin.000001 # Write_rows # # table_id: #
master-bin.000001 # Write_rows # # table_id: #
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.nt_5)
master-bin.000001 # Table_map # # table_id: # (test.nt_6)
master-bin.000001 # Write_rows # # table_id: #
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Query # # COMMIT
-e-e-e-e-e-e-e-e-e-e-e- >> NT-func << -e-e-e-e-e-e-e-e-e-e-e-
-b-b-b-b-b-b-b-b-b-b-b- >> NT-func << -b-b-b-b-b-b-b-b-b-b-b-
Log_name Pos Event_type Server_id End_log_pos Info
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.nt_5)
master-bin.000001 # Table_map # # table_id: # (test.nt_6)
master-bin.000001 # Write_rows # # table_id: #
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Query # # COMMIT
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_5)
master-bin.000001 # Table_map # # table_id: # (test.tt_6)
master-bin.000001 # Write_rows # # table_id: #
@ -497,72 +503,60 @@ master-bin.000001 # Write_rows # # table_id: #
master-bin.000001 # Write_rows # # table_id: #
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.nt_5)
master-bin.000001 # Table_map # # table_id: # (test.nt_6)
master-bin.000001 # Write_rows # # table_id: #
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Query # # COMMIT
-e-e-e-e-e-e-e-e-e-e-e- >> NT-func << -e-e-e-e-e-e-e-e-e-e-e-
-b-b-b-b-b-b-b-b-b-b-b- >> TN << -b-b-b-b-b-b-b-b-b-b-b-
UPDATE tt_4, nt_4 SET tt_4.info= "new text 28 --> 1", nt_4.info= "new text 28 --> 1" where nt_4.trans_id = tt_4.trans_id and tt_4.trans_id = 1;
Log_name Pos Event_type Server_id End_log_pos Info
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_4)
master-bin.000001 # Update_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.nt_4)
master-bin.000001 # Update_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Query # # COMMIT
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_4)
master-bin.000001 # Update_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
-e-e-e-e-e-e-e-e-e-e-e- >> TN << -e-e-e-e-e-e-e-e-e-e-e-
-b-b-b-b-b-b-b-b-b-b-b- >> TN << -b-b-b-b-b-b-b-b-b-b-b-
Log_name Pos Event_type Server_id End_log_pos Info
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_4)
master-bin.000001 # Update_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.nt_4)
master-bin.000001 # Update_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Query # # COMMIT
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_4)
master-bin.000001 # Update_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
-e-e-e-e-e-e-e-e-e-e-e- >> TN << -e-e-e-e-e-e-e-e-e-e-e-
-b-b-b-b-b-b-b-b-b-b-b- >> TN-trig << -b-b-b-b-b-b-b-b-b-b-b-
INSERT INTO tt_3(trans_id, stmt_id) VALUES (29, 1);
Log_name Pos Event_type Server_id End_log_pos Info
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_3)
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.nt_3)
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Query # # COMMIT
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_3)
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
-e-e-e-e-e-e-e-e-e-e-e- >> TN-trig << -e-e-e-e-e-e-e-e-e-e-e-
-b-b-b-b-b-b-b-b-b-b-b- >> TN-trig << -b-b-b-b-b-b-b-b-b-b-b-
Log_name Pos Event_type Server_id End_log_pos Info
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_3)
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.nt_3)
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Query # # COMMIT
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_3)
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
-e-e-e-e-e-e-e-e-e-e-e- >> TN-trig << -e-e-e-e-e-e-e-e-e-e-e-
-b-b-b-b-b-b-b-b-b-b-b- >> TN-func << -b-b-b-b-b-b-b-b-b-b-b-
INSERT INTO tt_5(trans_id, stmt_id, info) VALUES (30, 1, fc_i_nt_5_suc(30, 1));
Log_name Pos Event_type Server_id End_log_pos Info
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_5)
master-bin.000001 # Table_map # # table_id: # (test.tt_6)
master-bin.000001 # Write_rows # # table_id: #
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.nt_5)
master-bin.000001 # Table_map # # table_id: # (test.nt_6)
master-bin.000001 # Write_rows # # table_id: #
@ -570,16 +564,16 @@ master-bin.000001 # Write_rows # # table_id: #
master-bin.000001 # Write_rows # # table_id: #
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Query # # COMMIT
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_5)
master-bin.000001 # Table_map # # table_id: # (test.tt_6)
master-bin.000001 # Write_rows # # table_id: #
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
-e-e-e-e-e-e-e-e-e-e-e- >> TN-func << -e-e-e-e-e-e-e-e-e-e-e-
-b-b-b-b-b-b-b-b-b-b-b- >> TN-func << -b-b-b-b-b-b-b-b-b-b-b-
Log_name Pos Event_type Server_id End_log_pos Info
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_5)
master-bin.000001 # Table_map # # table_id: # (test.tt_6)
master-bin.000001 # Write_rows # # table_id: #
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.nt_5)
master-bin.000001 # Table_map # # table_id: # (test.nt_6)
master-bin.000001 # Write_rows # # table_id: #
@ -587,6 +581,12 @@ master-bin.000001 # Write_rows # # table_id: #
master-bin.000001 # Write_rows # # table_id: #
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Query # # COMMIT
master-bin.000001 # Query # # BEGIN
master-bin.000001 # Table_map # # table_id: # (test.tt_5)
master-bin.000001 # Table_map # # table_id: # (test.tt_6)
master-bin.000001 # Write_rows # # table_id: #
master-bin.000001 # Write_rows # # table_id: # flags: STMT_END_F
master-bin.000001 # Xid # # COMMIT /* XID */
-e-e-e-e-e-e-e-e-e-e-e- >> TN-func << -e-e-e-e-e-e-e-e-e-e-e-