MDEV-30317 Transaction savepoint may cause failure in galera replaying

Created mtr test for reproducing the crash

Developed actual fix for the issue.
Setting THD::system_thread_info.rpl_sql_info for replayer thread,
same way as it is handled for appliers.

Recorded test result, with the fix

Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

mysql-test/suite/galera/r/galera_savepoint_replay.result

@@ -0,0 +1,53 @@
+connection node_2;
+connection node_1;
+CREATE TABLE t1 (f1 INTEGER PRIMARY KEY, f2 CHAR(1));
+INSERT INTO t1 VALUES (1, 'a');
+INSERT INTO t1 VALUES (2, 'a');
+connection node_1;
+SET AUTOCOMMIT=ON;
+START TRANSACTION;
+UPDATE t1 SET f2 = 'b' WHERE f1 = 1;
+SELECT * FROM t1 WHERE f1 = 2 FOR UPDATE;
+f1	f2
+2	a
+SAVEPOINT my_sp;
+connect node_1a, 127.0.0.1, root, , test, $NODE_MYPORT_1;
+SET SESSION wsrep_sync_wait=0;
+SET GLOBAL wsrep_provider_options = 'dbug=d,apply_monitor_slave_enter_sync';
+connection node_2;
+UPDATE t1 SET f2 = 'c' WHERE f1 = 2;
+connection node_1a;
+SET SESSION wsrep_on = 0;
+SET SESSION wsrep_on = 1;
+SET GLOBAL wsrep_provider_options = 'dbug=';
+SET GLOBAL wsrep_provider_options = 'dbug=d,commit_monitor_master_enter_sync';
+connection node_1;
+COMMIT;
+connection node_1a;
+SET SESSION wsrep_on = 0;
+SET SESSION wsrep_on = 1;
+SET GLOBAL wsrep_provider_options = 'dbug=';
+SET GLOBAL wsrep_provider_options = 'dbug=d,abort_trx_end';
+SET GLOBAL wsrep_provider_options = 'signal=apply_monitor_slave_enter_sync';
+SET SESSION wsrep_on = 0;
+SET SESSION wsrep_on = 1;
+SET GLOBAL wsrep_provider_options = 'dbug=';
+SET GLOBAL wsrep_provider_options = 'signal=abort_trx_end';
+SET GLOBAL wsrep_provider_options = 'signal=commit_monitor_master_enter_sync';
+connection node_1;
+SELECT COUNT(*) = 1 FROM t1 WHERE f2 = 'b';
+COUNT(*) = 1
+1
+SELECT COUNT(*) = 1 FROM t1 WHERE f2 = 'c';
+COUNT(*) = 1
+1
+wsrep_local_replays
+1
+connection node_2;
+SELECT COUNT(*) = 1 FROM t1 WHERE f2 = 'b';
+COUNT(*) = 1
+1
+SELECT COUNT(*) = 1 FROM t1 WHERE f2 = 'c';
+COUNT(*) = 1
+1
+DROP TABLE t1;

mysql-test/suite/galera/t/galera_savepoint_replay.test

@@ -0,0 +1,86 @@
+#
+# This test tests replaying a transaction with savepoint
+#
+
+--source include/galera_cluster.inc
+--source include/have_innodb.inc
+--source include/have_debug_sync.inc
+--source include/galera_have_debug_sync.inc
+
+--let $wsrep_local_replays_old = `SELECT VARIABLE_VALUE FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_local_replays'`
+
+CREATE TABLE t1 (f1 INTEGER PRIMARY KEY, f2 CHAR(1));
+INSERT INTO t1 VALUES (1, 'a');
+INSERT INTO t1 VALUES (2, 'a');
+
+--connection node_1
+SET AUTOCOMMIT=ON;
+START TRANSACTION;
+
+UPDATE t1 SET f2 = 'b' WHERE f1 = 1;
+SELECT * FROM t1 WHERE f1 = 2 FOR UPDATE;
+SAVEPOINT my_sp;
+
+# Block the applier on node #1 and issue a conflicting update on node #2
+--connect node_1a, 127.0.0.1, root, , test, $NODE_MYPORT_1
+SET SESSION wsrep_sync_wait=0;
+--let $galera_sync_point = apply_monitor_slave_enter_sync
+--source include/galera_set_sync_point.inc
+
+--connection node_2
+UPDATE t1 SET f2 = 'c' WHERE f1 = 2;
+
+--connection node_1a
+--source include/galera_wait_sync_point.inc
+--source include/galera_clear_sync_point.inc
+
+# Block the commit, send the COMMIT and wait until it gets blocked
+
+--let $galera_sync_point = commit_monitor_master_enter_sync
+--source include/galera_set_sync_point.inc
+
+--connection node_1
+--send COMMIT
+
+--connection node_1a
+
+--let $galera_sync_point = apply_monitor_slave_enter_sync commit_monitor_master_enter_sync
+--source include/galera_wait_sync_point.inc
+--source include/galera_clear_sync_point.inc
+
+# Let the conflicting UPDATE proceed and wait until it hits abort_trx_end.
+# The victim transaction still sits in commit_monitor_master_sync_point.
+
+--let $galera_sync_point = abort_trx_end
+--source include/galera_set_sync_point.inc
+--let $galera_sync_point = apply_monitor_slave_enter_sync
+--source include/galera_signal_sync_point.inc
+--let $galera_sync_point = abort_trx_end commit_monitor_master_enter_sync
+--source include/galera_wait_sync_point.inc
+
+# Let the transactions proceed
+--source include/galera_clear_sync_point.inc
+--let $galera_sync_point = abort_trx_end
+--source include/galera_signal_sync_point.inc
+--let $galera_sync_point = commit_monitor_master_enter_sync
+--source include/galera_signal_sync_point.inc
+
+# Commit succeeds
+--connection node_1
+--reap
+
+SELECT COUNT(*) = 1 FROM t1 WHERE f2 = 'b';
+SELECT COUNT(*) = 1 FROM t1 WHERE f2 = 'c';
+
+# wsrep_local_replays has increased by 1
+--let $wsrep_local_replays_new = `SELECT VARIABLE_VALUE FROM INFORMATION_SCHEMA.GLOBAL_STATUS WHERE VARIABLE_NAME = 'wsrep_local_replays'`
+--disable_query_log
+--eval SELECT $wsrep_local_replays_new - $wsrep_local_replays_old = 1 AS wsrep_local_replays;
+--enable_query_log
+
+--connection node_2
+SELECT COUNT(*) = 1 FROM t1 WHERE f2 = 'b';
+SELECT COUNT(*) = 1 FROM t1 WHERE f2 = 'c';
+
+DROP TABLE t1;
+

sql/wsrep_high_priority_service.cc

@@ -1,4 +1,4 @@
-/* Copyright 2018-2021 Codership Oy <info@codership.com>
+/* Copyright 2018-2023 Codership Oy <info@codership.com>
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -619,6 +619,9 @@ Wsrep_replayer_service::Wsrep_replayer_service(THD* replayer_thd, THD* orig_thd)
      transactional locks */
   DBUG_ASSERT(!orig_thd->mdl_context.has_transactional_locks());
 
+  replayer_thd->system_thread_info.rpl_sql_info=
+    new rpl_sql_thread_info(replayer_thd->wsrep_rgi->rli->mi->rpl_filter);
+
   /* Make a shadow copy of diagnostics area and reset */
   m_da_shadow.status= orig_thd->get_stmt_da()->status();
   if (m_da_shadow.status == Diagnostics_area::DA_OK)
@@ -657,35 +660,35 @@ Wsrep_replayer_service::Wsrep_replayer_service(THD* replayer_thd, THD* orig_thd)
 
 Wsrep_replayer_service::~Wsrep_replayer_service()
 {
-  THD* replayer_thd= m_thd;
-  THD* orig_thd= m_orig_thd;
-
   /* Switch execution context back to original. */
-  wsrep_after_apply(replayer_thd);
-  wsrep_after_command_ignore_result(replayer_thd);
-  wsrep_close(replayer_thd);
-  wsrep_reset_threadvars(replayer_thd);
-  wsrep_store_threadvars(orig_thd);
+  wsrep_after_apply(m_thd);
+  wsrep_after_command_ignore_result(m_thd);
+  wsrep_close(m_thd);
+  wsrep_reset_threadvars(m_thd);
+  wsrep_store_threadvars(m_orig_thd);
 
-  DBUG_ASSERT(!orig_thd->get_stmt_da()->is_sent());
-  DBUG_ASSERT(!orig_thd->get_stmt_da()->is_set());
+  DBUG_ASSERT(!m_orig_thd->get_stmt_da()->is_sent());
+  DBUG_ASSERT(!m_orig_thd->get_stmt_da()->is_set());
+
+  delete m_thd->system_thread_info.rpl_sql_info;
+  m_thd->system_thread_info.rpl_sql_info= nullptr;
 
   if (m_replay_status == wsrep::provider::success)
   {
-    DBUG_ASSERT(replayer_thd->wsrep_cs().current_error() == wsrep::e_success);
-    orig_thd->reset_kill_query();
-    my_ok(orig_thd, m_da_shadow.affected_rows, m_da_shadow.last_insert_id);
+    DBUG_ASSERT(m_thd->wsrep_cs().current_error() == wsrep::e_success);
+    m_orig_thd->reset_kill_query();
+    my_ok(m_orig_thd, m_da_shadow.affected_rows, m_da_shadow.last_insert_id);
   }
   else if (m_replay_status == wsrep::provider::error_certification_failed)
   {
-    wsrep_override_error(orig_thd, ER_LOCK_DEADLOCK);
+    wsrep_override_error(m_orig_thd, ER_LOCK_DEADLOCK);
   }
   else
   {
     DBUG_ASSERT(0);
     WSREP_ERROR("trx_replay failed for: %d, schema: %s, query: %s",
                 m_replay_status,
-                orig_thd->db.str, wsrep_thd_query(orig_thd));
+                m_orig_thd->db.str, wsrep_thd_query(m_orig_thd));
     unireg_abort(1);
   }
 }