mirror of
https://github.com/MariaDB/server.git
synced 2025-11-04 12:56:14 +01:00
235f33e360
It's possible that MDL conflict handling code is called more than once for a transaction when: - it holds more than one conflicting MDL lock - reschedule_waiters() is executed, which results in repeated attempts to BF-abort already aborted transaction. In such situations, it might be that BF-aborting logic sees a partially rolled back transaction and erroneously decides on future actions for such a transaction. The specific situation tested and fixed is when a SR transaction applied in the node gets BF-aborted by a started TOI operation. It's then caught with the server transaction already rolled back, but with no MDL locks yet released. This caused wrong state detection for such a transaction during repeated MDL conflict handling code execution. Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>
80 lines
2.5 KiB
Text
80 lines
2.5 KiB
Text
#
|
|
# MDEV-33133: MDL conflict handling code should skip transactions
|
|
# BF-aborted before.
|
|
#
|
|
# It's possible that MDL conflict handling code is called more
|
|
# than once for a transaction when:
|
|
# - it holds more than one conflicting MDL lock
|
|
# - reschedule_waiters() is executed,
|
|
# which results in repeated attempts to BF-abort already aborted
|
|
# transaction.
|
|
# In such situations, it might be that BF-aborting logic sees
|
|
# a partially rolled back transaction and erroneously decides
|
|
# on future actions for such a transaction.
|
|
#
|
|
# The specific situation tested and fixed is when a SR transaction
|
|
# applied in the node gets BF-aborted by a started TOI operation.
|
|
# It's then caught with the server transaction already rolled back,
|
|
# but with no MDL locks yet released. This caused wrong state
|
|
# detection for such a transaction during repeated MDL conflict
|
|
# handling code execution.
|
|
#
|
|
|
|
--source include/galera_cluster.inc
|
|
--source include/have_debug_sync.inc
|
|
--source include/have_debug.inc
|
|
|
|
--connect node_1a,127.0.0.1,root,,test,$NODE_MYPORT_1
|
|
|
|
--connection node_1
|
|
CREATE TABLE t1 (f1 INTEGER PRIMARY KEY) ENGINE=InnoDB;
|
|
SET GLOBAL DEBUG_DBUG = 'd,sync.wsrep_rollback_mdl_release';
|
|
|
|
--connection node_2
|
|
SET SESSION wsrep_trx_fragment_size = 1;
|
|
START TRANSACTION;
|
|
INSERT INTO t1 VALUES (1);
|
|
|
|
--connection node_1a
|
|
# Sync wait for SR transaction to replicate and apply fragment.
|
|
SELECT COUNT(*) FROM t1;
|
|
SET SESSION wsrep_retry_autocommit = 0;
|
|
SET DEBUG_SYNC = 'ha_write_row_start SIGNAL may_toi WAIT_FOR bf_abort';
|
|
--send
|
|
INSERT INTO t1 VALUES (2);
|
|
|
|
--connection node_1
|
|
SET DEBUG_SYNC = 'now WAIT_FOR may_toi';
|
|
# BF-abort SR transaction and wait until it reaches the point
|
|
# prior to release MDL locks.
|
|
# Then abort local INSERT, which will go through rescedule_waiters()
|
|
# and see SR transaction holding MDL locks but already rolled back.
|
|
# In this case SR transaction should be skipped in MDL conflict
|
|
# handling code.
|
|
SET DEBUG_SYNC = 'after_wsrep_thd_abort WAIT_FOR sync.wsrep_rollback_mdl_release_reached';
|
|
--send
|
|
TRUNCATE TABLE t1;
|
|
|
|
--connection node_1a
|
|
# Local INSERT gets aborted.
|
|
--error ER_LOCK_DEADLOCK
|
|
--reap
|
|
# Let the aborted SR transaction continue and finally release MDL locks,
|
|
# which in turn allows TRUNCATE to complete.
|
|
SET DEBUG_SYNC = 'now SIGNAL signal.wsrep_rollback_mdl_release';
|
|
|
|
--connection node_2
|
|
# SR transaction has been BF-aborted.
|
|
--error ER_LOCK_DEADLOCK
|
|
INSERT INTO t1 VALUES (3);
|
|
|
|
--connection node_1
|
|
# TRUNCATE completes.
|
|
--reap
|
|
|
|
# Cleanup
|
|
SET GLOBAL DEBUG_DBUG = '';
|
|
SET DEBUG_SYNC = 'RESET';
|
|
DROP TABLE t1;
|
|
--disconnect node_1a
|
|
--source include/galera_end.inc
|