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MDEV-36360: Don't grab table-level X locks for applied inserts

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It prevents a crash in wsrep_report_error() which happened when appliers would run
with FK and UK checks disabled and erroneously execute plain inserts as bulk inserts.

Moreover, in release builds such a behavior could lead to deadlocks between two applier
threads if a thread waiting for a table-level lock was ordered before the lock holder.
In that case the lock holder would proceed to commit order and wait forever for the
now-blocked other applier thread to commit before.

Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>
This commit is contained in:
Denis Protivensky 2025-03-25 13:59:00 +03:00 committed by Julius Goryavsky
parent b983a911e9
commit c01bff4a10
5 changed files with 210 additions and 8 deletions
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61
mysql-test/suite/galera_3nodes/r/MDEV-36360.result Normal file
View File

@ -0,0 +1,61 @@
connection node_2;
connection node_1;
connection node_1;
connection node_2;
connection node_3;
connection node_1;
CREATE TABLE parent (
id INT PRIMARY KEY
) ENGINE=InnoDB;
CREATE TABLE child (
id INT PRIMARY KEY,
parent_id INT,
KEY (parent_id),
CONSTRAINT FOREIGN KEY (parent_id) REFERENCES parent(id)
) ENGINE=InnoDB;
INSERT INTO parent VALUES (1), (2);
connection node_3;
SET SESSION wsrep_on = OFF;
DELETE FROM parent WHERE id = 1;
SET SESSION wsrep_on = ON;
Restarting server 3 with one applier thread having FK and UK checks disabled
SET GLOBAL DEBUG_DBUG = 'd,sync.wsrep_after_write_row';
connection node_1;
INSERT INTO child VALUES (1, 1);
connection node_3;
SET DEBUG_SYNC = 'now WAIT_FOR sync.wsrep_after_write_row_reached';
SET GLOBAL DEBUG_DBUG = '';
SET wsrep_sync_wait = 0;
SET DEBUG_SYNC = 'ib_after_row_insert SIGNAL signal.wsrep_after_write_row';
INSERT INTO child VALUES (2, 2);
SET DEBUG_SYNC = 'RESET';
include/assert_grep.inc [no FK constraint failure]
Server 3
SELECT COUNT(*) AS EXPECT_1 FROM parent;
EXPECT_1
1
SELECT COUNT(*) AS EXPECT_2 FROM child;
EXPECT_2
2
connection node_1;
Server 1
SET wsrep_sync_wait = 15;
SELECT COUNT(*) AS EXPECT_2 FROM parent;
EXPECT_2
2
SELECT COUNT(*) AS EXPECT_2 FROM child;
EXPECT_2
2
connection node_2;
Server 2
SET wsrep_sync_wait = 15;
SELECT COUNT(*) AS EXPECT_2 FROM parent;
EXPECT_2
2
SELECT COUNT(*) AS EXPECT_2 FROM child;
EXPECT_2
2
DROP TABLE child;
DROP TABLE parent;
disconnect node_2;
disconnect node_1;

110
mysql-test/suite/galera_3nodes/t/MDEV-36360.test Normal file
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@ -0,0 +1,110 @@
#
# MDEV-36360: Don't grab table-level X locks for applied inserts.
#
# It prevents a debug crash in wsrep_report_error() which happened when appliers would run
# with FK and UK checks disabled and erroneously execute plain inserts as bulk inserts.
#
# Moreover, in release builds such a behavior could lead to deadlocks between two applier
# threads if a thread waiting for a table-level lock was ordered before the lock holder.
# In that case the lock holder would proceed to commit order and wait forever for the
# now-blocked other applier thread to commit before.
#
--source include/galera_cluster.inc
--source include/have_innodb.inc
--source include/have_debug_sync.inc
--source include/have_debug.inc
--let $galera_connection_name = node_3
--let $galera_server_number = 3
--source include/galera_connect.inc
# Save original auto_increment_offset values.
--let $node_1=node_1
--let $node_2=node_2
--let $node_3=node_3
--source ../galera/include/auto_increment_offset_save.inc
# Create parent and child tables.
--connection node_1
CREATE TABLE parent (
id INT PRIMARY KEY
) ENGINE=InnoDB;
CREATE TABLE child (
id INT PRIMARY KEY,
parent_id INT,
KEY (parent_id),
CONSTRAINT FOREIGN KEY (parent_id) REFERENCES parent(id)
) ENGINE=InnoDB;
# Fill the parent table with rows that will later be used by the child.
INSERT INTO parent VALUES (1), (2);
# Wait until the rows are replicated on node #3.
--connection node_3
--let $wait_condition = SELECT COUNT(*) = 2 FROM parent
--source include/wait_condition.inc
# Delete one row from the parent table on node #3 and rejoin the cluster.
SET SESSION wsrep_on = OFF;
DELETE FROM parent WHERE id = 1;
SET SESSION wsrep_on = ON;
--echo Restarting server 3 with one applier thread having FK and UK checks disabled
--source include/shutdown_mysqld.inc
--let $start_mysqld_params = --wsrep_slave_FK_checks=0 --wsrep_slave_UK_checks=0
--source ../galera/include/start_mysqld.inc
# Stop the applier after writing a row into the child table.
SET GLOBAL DEBUG_DBUG = 'd,sync.wsrep_after_write_row';
# Insert a child row that will be applied on node #3, but should not
# grab table-level X-lock.
--connection node_1
INSERT INTO child VALUES (1, 1);
--connection node_3
SET DEBUG_SYNC = 'now WAIT_FOR sync.wsrep_after_write_row_reached';
# Now that the applier has hit the global sync point wait, reset it
# so that the upcoming insert avoids it.
SET GLOBAL DEBUG_DBUG = '';
# Don't wait for applied insert to commit.
SET wsrep_sync_wait = 0;
SET DEBUG_SYNC = 'ib_after_row_insert SIGNAL signal.wsrep_after_write_row';
# The insert should pass the sync point, as otherwise if the applied insert
# grabs table-level X-lock, they'll both deadlock forever.
INSERT INTO child VALUES (2, 2);
SET DEBUG_SYNC = 'RESET';
--let $assert_select = foreign key constraint fails
--let $assert_count = 0
--let $assert_text = no FK constraint failure
--let $assert_only_after = CURRENT_TEST
--let $assert_file = $MYSQLTEST_VARDIR/log/mysqld.3.err
--source include/assert_grep.inc
# Child row insert is applied even though there's no parent row.
--echo Server 3
SELECT COUNT(*) AS EXPECT_1 FROM parent;
SELECT COUNT(*) AS EXPECT_2 FROM child;
# Check other nodes have both parent and child rows.
--connection node_1
--echo Server 1
SET wsrep_sync_wait = 15;
SELECT COUNT(*) AS EXPECT_2 FROM parent;
SELECT COUNT(*) AS EXPECT_2 FROM child;
--connection node_2
--echo Server 2
SET wsrep_sync_wait = 15;
SELECT COUNT(*) AS EXPECT_2 FROM parent;
SELECT COUNT(*) AS EXPECT_2 FROM child;
DROP TABLE child;
DROP TABLE parent;
# Restore original auto_increment_offset values.
--source ../galera/include/auto_increment_offset_restore.inc
--source include/galera_end.inc

15
sql/wsrep_applier.cc
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@ -203,6 +203,21 @@ int wsrep_apply_events(THD* thd,
}
}
if (LOG_EVENT_IS_WRITE_ROW(typ) ||
LOG_EVENT_IS_UPDATE_ROW(typ) ||
LOG_EVENT_IS_DELETE_ROW(typ))
{
Rows_log_event* rle = static_cast<Rows_log_event*>(ev);
if (thd_test_options(thd, OPTION_RELAXED_UNIQUE_CHECKS))
{
rle->set_flags(Rows_log_event::RELAXED_UNIQUE_CHECKS_F);
}
if (thd_test_options(thd, OPTION_NO_FOREIGN_KEY_CHECKS))
{
rle->set_flags(Rows_log_event::NO_FOREIGN_KEY_CHECKS_F);
}
}
/* Use the original server id for logging. */
thd->set_server_id(ev->server_id);
thd->lex->current_select= 0;

11
storage/innobase/handler/ha_innodb.cc
View File

@ -7986,6 +7986,17 @@ set_max_autoinc:
error, m_prebuilt->table->flags, m_user_thd);
#ifdef WITH_WSREP
#ifdef ENABLED_DEBUG_SYNC
DBUG_EXECUTE_IF("sync.wsrep_after_write_row",
{
const char act[]=
"now "
"SIGNAL sync.wsrep_after_write_row_reached "
"WAIT_FOR signal.wsrep_after_write_row";
DBUG_ASSERT(!debug_sync_set_action(m_user_thd, STRING_WITH_LEN(act)));
};);
#endif /* ENABLED_DEBUG_SYNC */
if (!error_result && trx->is_wsrep()
&& !trx->is_bulk_insert()
&& wsrep_thd_is_local(m_user_thd)

21
storage/innobase/row/row0ins.cc
View File

@ -2733,6 +2733,15 @@ err_exit:
DBUG_EXECUTE_IF("row_ins_row_level", goto skip_bulk_insert;);
#ifdef WITH_WSREP
/* Appliers never execute bulk insert statements directly. */
if (trx->is_wsrep() &&
!wsrep_thd_is_local_transaction(trx->mysql_thd))
{
goto skip_bulk_insert;
}
#endif /* WITH_WSREP */
if (!(flags & BTR_NO_UNDO_LOG_FLAG)
&& page_is_empty(block->page.frame)
&& !entry->is_metadata() && !trx->duplicates
@ -2760,15 +2769,11 @@ err_exit:
}
#ifdef WITH_WSREP
if (trx->is_wsrep())
if (trx->is_wsrep() &&
wsrep_append_table_key(trx->mysql_thd, *index->table))
{
if (!wsrep_thd_is_local_transaction(trx->mysql_thd))
goto skip_bulk_insert;
if (wsrep_append_table_key(trx->mysql_thd, *index->table))
{
trx->error_state = DB_ROLLBACK;
goto err_exit;
}
trx->error_state = DB_ROLLBACK;
goto err_exit;
}
#endif /* WITH_WSREP */