MDEV-25039: MDL BF-BF conflict on ALTER and INSERT with multi-level foreign key parents

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

@@ -48,7 +48,6 @@ connection node_2;
 SET DEBUG_SYNC = "now WAIT_FOR sync.wsrep_apply_toi_reached";
 SET SESSION wsrep_sync_wait = 0;
 connection node_1;
-SET GLOBAL DEBUG_DBUG = '+d,wsrep_print_foreign_keys_table';
 START TRANSACTION;
 INSERT INTO t1 VALUES (3,0);
 COMMIT;
@@ -62,10 +61,6 @@ connection node_1;
 SET DEBUG_SYNC = 'RESET';
 SET GLOBAL DEBUG_DBUG = "";
 SET GLOBAL wsrep_slave_threads=DEFAULT;
-connection node_1;
-include/assert_grep.inc [Foreign key referenced table found: 2 tables]
-include/assert_grep.inc [Foreign key referenced table found: test.t2]
-include/assert_grep.inc [Foreign key referenced table found: test.t3]
 connection node_2;
 select * from t1;
 id	f2
@@ -146,7 +141,6 @@ connection node_2;
 SET DEBUG_SYNC = "now WAIT_FOR sync.wsrep_apply_toi_reached";
 SET SESSION wsrep_sync_wait = 0;
 connection node_1;
-SET GLOBAL DEBUG_DBUG = '+d,wsrep_print_foreign_keys_table';
 START TRANSACTION;
 INSERT INTO t1 VALUES (3,0);
 COMMIT;
@@ -160,11 +154,6 @@ connection node_1;
 SET DEBUG_SYNC = 'RESET';
 SET GLOBAL DEBUG_DBUG = "";
 SET GLOBAL wsrep_slave_threads=DEFAULT;
-connection node_1;
-include/assert_grep.inc [Foreign key referenced table found: 3 tables]
-include/assert_grep.inc [Foreign key referenced table found: test.t2]
-include/assert_grep.inc [Foreign key referenced table found: test.t3]
-include/assert_grep.inc [Foreign key referenced table found: test.t4]
 connection node_2;
 select * from t1;
 id	f2
@@ -233,7 +222,6 @@ connection node_2;
 SET DEBUG_SYNC = "now WAIT_FOR sync.wsrep_apply_toi_reached";
 SET SESSION wsrep_sync_wait = 0;
 connection node_1;
-SET GLOBAL DEBUG_DBUG = '+d,wsrep_print_foreign_keys_table';
 START TRANSACTION;
 INSERT INTO t1 VALUES (3,0);
 COMMIT;
@@ -247,11 +235,6 @@ connection node_1;
 SET DEBUG_SYNC = 'RESET';
 SET GLOBAL DEBUG_DBUG = "";
 SET GLOBAL wsrep_slave_threads=DEFAULT;
-connection node_1;
-include/assert_grep.inc [Foreign key referenced table found: 2 tables]
-include/assert_grep.inc [Foreign key referenced table found: test.t2]
-include/assert_grep.inc [Foreign key referenced table found: test.t3]
-include/assert_grep.inc [Foreign key referenced table found: test.t4]
 connection node_2;
 select * from t1;
 id	f2
@@ -323,7 +306,6 @@ connection node_2;
 SET DEBUG_SYNC = "now WAIT_FOR sync.wsrep_apply_toi_reached";
 SET SESSION wsrep_sync_wait = 0;
 connection node_1;
-SET GLOBAL DEBUG_DBUG = '+d,wsrep_print_foreign_keys_table';
 START TRANSACTION;
 INSERT INTO t1 VALUES (3,0);
 COMMIT;
@@ -337,10 +319,6 @@ connection node_1;
 SET DEBUG_SYNC = 'RESET';
 SET GLOBAL DEBUG_DBUG = "";
 SET GLOBAL wsrep_slave_threads=DEFAULT;
-connection node_1;
-include/assert_grep.inc [Foreign key referenced table found: 1 tables]
-include/assert_grep.inc [Foreign key referenced table found: test.t2]
-include/assert_grep.inc [Foreign key referenced table found: test.t3]
 connection node_2;
 select * from t1;
 id	f2

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

@@ -72,35 +72,8 @@ INSERT INTO t4 VALUES (2,2,1234);
 
 --let $fk_parent_query = DROP TABLE t4
 --let $fk_child_query = INSERT INTO t1 VALUES (3,0)
---let $fk_mdl_lock_num = 3
---source galera_multi_level_foreign_key.inc
-
-
-#
-# Verify Foreign key for referenced table added.
-#
---connection node_1
---let assert_text= Foreign key referenced table found: 2 tables
---let $assert_file= $MYSQLTEST_VARDIR/log/mysqld.1.err
---let assert_count= 2
---let assert_select= Foreign key referenced table found:
---let assert_only_after= CURRENT_TEST: galera.galera_multi_level_fk_ddl_insert
---source include/assert_grep.inc
-
---let assert_text= Foreign key referenced table found: test.t2
---let $assert_file= $MYSQLTEST_VARDIR/log/mysqld.1.err
---let assert_count= 1
---let assert_select= Foreign key referenced table found: test.t2
---let assert_only_after= CURRENT_TEST: galera.galera_multi_level_fk_ddl_insert
---source include/assert_grep.inc
-
---let assert_text= Foreign key referenced table found: test.t3
---let $assert_file= $MYSQLTEST_VARDIR/log/mysqld.1.err
---let assert_count= 1
---let assert_select= Foreign key referenced table found: test.t3
---let assert_only_after= CURRENT_TEST: galera.galera_multi_level_fk_ddl_insert
---source include/assert_grep.inc
-
+--let $fk_mdl_lock_num = 2
+--source galera_multi_level_foreign_key_insert.inc
 
 #
 # Verify insert and drop table has succeded.
@@ -191,41 +164,8 @@ INSERT INTO t4 VALUES (2,2,1234);
 # Issue a INSERT to table that references t1
 #
 --let $fk_child_query = INSERT INTO t1 VALUES (3,0)
---let $fk_mdl_lock_num = 4
---source galera_multi_level_foreign_key.inc
-
-
-#
-# Verify Foreign key for referenced table added.
-#
---connection node_1
---let assert_text= Foreign key referenced table found: 3 tables
---let $assert_file= $MYSQLTEST_VARDIR/log/mysqld.1.err
---let assert_count= 5
---let assert_select= Foreign key referenced table found:
---let assert_only_after= CURRENT_TEST: galera.galera_multi_level_fk_ddl_insert
---source include/assert_grep.inc
-
---let assert_text= Foreign key referenced table found: test.t2
---let $assert_file= $MYSQLTEST_VARDIR/log/mysqld.1.err
---let assert_count= 2
---let assert_select= Foreign key referenced table found: test.t2
---let assert_only_after= CURRENT_TEST: galera.galera_multi_level_fk_ddl_insert
---source include/assert_grep.inc
-
---let assert_text= Foreign key referenced table found: test.t3
---let $assert_file= $MYSQLTEST_VARDIR/log/mysqld.1.err
---let assert_count= 2
---let assert_select= Foreign key referenced table found: test.t3
---let assert_only_after= CURRENT_TEST: galera.galera_multi_level_fk_ddl_insert
---source include/assert_grep.inc
-
---let assert_text= Foreign key referenced table found: test.t4
---let $assert_file= $MYSQLTEST_VARDIR/log/mysqld.1.err
---let assert_count= 1
---let assert_select= Foreign key referenced table found: test.t4
---let assert_only_after= CURRENT_TEST: galera.galera_multi_level_fk_ddl_insert
---source include/assert_grep.inc
+--let $fk_mdl_lock_num = 2
+--source galera_multi_level_foreign_key_insert.inc
 
 
 #
@@ -296,42 +236,8 @@ INSERT INTO t3 VALUES (2,2,1234);
 
 --let $fk_parent_query = CREATE TABLE t4 (id INT PRIMARY KEY, t3_id INT NOT NULL, f2 INTEGER NOT NULL, KEY key_t3_id(t3_id), CONSTRAINT key_t3_id FOREIGN KEY (t3_id) REFERENCES t3 (id) ON UPDATE CASCADE ON DELETE CASCADE)
 --let $fk_child_query = INSERT INTO t1 VALUES (3,0)
---let $fk_mdl_lock_num = 4
---source galera_multi_level_foreign_key.inc
-
-
-#
-# Verify Foreign key for referenced table added.
-#
---connection node_1
---let assert_text= Foreign key referenced table found: 2 tables
---let $assert_file= $MYSQLTEST_VARDIR/log/mysqld.1.err
---let assert_count= 8
---let assert_select= Foreign key referenced table found:
---let $assert_only_after = CURRENT_TEST:
---let assert_only_after= CURRENT_TEST: galera.galera_multi_level_fk_ddl_insert
---source include/assert_grep.inc
-
---let assert_text= Foreign key referenced table found: test.t2
---let $assert_file= $MYSQLTEST_VARDIR/log/mysqld.1.err
---let assert_count= 3
---let assert_select= Foreign key referenced table found: test.t2
---let assert_only_after= CURRENT_TEST: galera.galera_multi_level_fk_ddl_insert
---source include/assert_grep.inc
-
---let assert_text= Foreign key referenced table found: test.t3
---let $assert_file= $MYSQLTEST_VARDIR/log/mysqld.1.err
---let assert_count= 3
---let assert_select= Foreign key referenced table found: test.t3
---let assert_only_after= CURRENT_TEST: galera.galera_multi_level_fk_ddl_insert
---source include/assert_grep.inc
-
---let assert_text= Foreign key referenced table found: test.t4
---let $assert_file= $MYSQLTEST_VARDIR/log/mysqld.1.err
---let assert_count= 2
---let assert_select= Foreign key referenced table found: test.t4
---let assert_only_after= CURRENT_TEST: galera.galera_multi_level_fk_ddl_insert
---source include/assert_grep.inc
+--let $fk_mdl_lock_num = 2
+--source galera_multi_level_foreign_key_insert.inc
 
 
 #
@@ -403,35 +309,8 @@ INSERT INTO t3 VALUES (2,2,1234);
 
 --let $fk_parent_query = OPTIMIZE TABLE t3
 --let $fk_child_query = INSERT INTO t1 VALUES (3,0)
---let $fk_mdl_lock_num = 3
---source galera_multi_level_foreign_key.inc
-
-
-#
-# Verify Foreign key for referenced table added.
-#
---connection node_1
---let assert_text= Foreign key referenced table found: 1 tables
---let $assert_file= $MYSQLTEST_VARDIR/log/mysqld.1.err
---let assert_count= 10
---let assert_select= Foreign key referenced table found:
---let $assert_only_after = CURRENT_TEST:
---let assert_only_after= CURRENT_TEST: galera.galera_multi_level_fk_ddl_insert
---source include/assert_grep.inc
-
---let assert_text= Foreign key referenced table found: test.t2
---let $assert_file= $MYSQLTEST_VARDIR/log/mysqld.1.err
---let assert_count= 4
---let assert_select= Foreign key referenced table found: test.t2
---let assert_only_after= CURRENT_TEST: galera.galera_multi_level_fk_ddl_insert
---source include/assert_grep.inc
-
---let assert_text= Foreign key referenced table found: test.t3
---let $assert_file= $MYSQLTEST_VARDIR/log/mysqld.1.err
---let assert_count= 4
---let assert_select= Foreign key referenced table found: test.t3
---let assert_only_after= CURRENT_TEST: galera.galera_multi_level_fk_ddl_insert
---source include/assert_grep.inc
+--let $fk_mdl_lock_num = 2
+--source galera_multi_level_foreign_key_insert.inc
 
 
 #

mysql-test/suite/galera/t/galera_multi_level_foreign_key_insert.inc

@@ -0,0 +1,44 @@
+
+--connection node_2
+SET GLOBAL DEBUG_DBUG = '+d,sync.wsrep_apply_toi';
+
+--connection node_1
+--eval $fk_parent_query
+
+--connection node_2
+SET DEBUG_SYNC = "now WAIT_FOR sync.wsrep_apply_toi_reached";
+SET SESSION wsrep_sync_wait = 0;
+
+#
+# Execute child query on node_1.
+# If bug is present, expect the wait condition
+# to timeout and when the child query applies, it
+# will be granted a MDL lock on parent table.
+# When resumed, the parent query will
+# also try to acquire MDL lock on parent table,
+# causing a BF-BF conflict on that MDL lock.
+#
+--connection node_1
+START TRANSACTION;
+--eval $fk_child_query
+--let $wait_condition = SELECT COUNT(*) = $fk_mdl_lock_num FROM performance_schema.metadata_locks WHERE OBJECT_SCHEMA='test' AND LOCK_STATUS="GRANTED"
+--source include/wait_condition.inc
+COMMIT;
+
+
+--connection node_2
+SET GLOBAL DEBUG_DBUG = '-d,sync.wsrep_apply_toi';
+SET DEBUG_SYNC = "now SIGNAL signal.wsrep_apply_toi";
+
+
+#
+# Cleanup
+#
+SET DEBUG_SYNC = 'RESET';
+SET GLOBAL DEBUG_DBUG = "";
+SET GLOBAL wsrep_slave_threads=DEFAULT;
+
+--connection node_1
+SET DEBUG_SYNC = 'RESET';
+SET GLOBAL DEBUG_DBUG = "";
+SET GLOBAL wsrep_slave_threads=DEFAULT;

sql/log_event_server.cc

@@ -8001,11 +8001,23 @@ Write_rows_log_event::do_exec_row(rpl_group_info *rgi)
 #if defined(HAVE_REPLICATION)
 uint8 Write_rows_log_event::get_trg_event_map()
 {
-  return trg2bit(TRG_EVENT_INSERT) | trg2bit(TRG_EVENT_UPDATE) |
-         trg2bit(TRG_EVENT_DELETE);
+  /*
+    In SLAVE_EXEC_MODE_IDEMPOTENT mode, Write_rows_log_event event is
+    implicitly a REPLACE, deleting all conflicting rows which can cause
+    foreign key constraint cascade operations on FK referencing table.
+
+    In SLAVE_EXEC_MODE_STRICT mode, the Write_rows_log_event is pure INSERT,
+    will never cause foreign key constraint cascade operations on foreign key
+    referencing tables.
+  */
+  if (slave_exec_mode_options == SLAVE_EXEC_MODE_IDEMPOTENT)
+    return trg2bit(TRG_EVENT_INSERT) | trg2bit(TRG_EVENT_DELETE);
+  else
+    return trg2bit(TRG_EVENT_INSERT);
 }
 #endif
 
+
 /**************************************************************************
 	Delete_rows_log_event member functions
 **************************************************************************/

sql/sql_base.cc

@@ -3965,15 +3965,6 @@ bool extend_table_list(THD *thd, TABLE_LIST *tables,
     (tables->updating && tables->lock_type >= TL_FIRST_WRITE)
     || thd->lex->default_used;
 
-#ifdef WITH_WSREP
-  if (WSREP(thd) && !thd->wsrep_applier &&
-      wsrep_is_active(thd) &&
-      (sql_command_flags[thd->lex->sql_command] & CF_INSERTS_DATA) &&
-      tables->lock_type == TL_READ) {
-    maybe_need_prelocking= true;
-  }
-#endif
-
   if (thd->locked_tables_mode <= LTM_LOCK_TABLES &&
       ! has_prelocking_list && maybe_need_prelocking)
   {
@@ -5106,7 +5097,6 @@ prepare_fk_prelocking_list(THD *thd, Query_tables_list *prelocking_ctx,
   Query_arena *arena, backup;
   TABLE *table= table_list->table;
   bool error= FALSE;
-  bool override_fk_ignore_table= FALSE;
 
   if (!table->file->referenced_by_foreign_key())
     DBUG_RETURN(FALSE);
@@ -5123,37 +5113,6 @@ prepare_fk_prelocking_list(THD *thd, Query_tables_list *prelocking_ctx,
 
   *need_prelocking= TRUE;
 
-#ifdef WITH_WSREP
-    /*
-      MDL is enough for read-only FK checks, we don't need the table,
-      but on galera applier node lock_type is set to TL_FIRST_WRITE and not
-      TL_READ, which is due to Write_rows_log_event event logged for INSERT
-      is used to record insert, update and delete
-      (Write_rows_log_event::get_trg_event_map()), and therefore all child
-      tables will be opened and MDL locks will be taken on applier node, while
-      opening  of multiple child tables is ignored on write node by setting
-      open_strategy= OPEN_STUB in init_one_table_for_prelocking().
-      This difference in write and applier node can result in MDL deadlock.
-      Tables with foreign keys: t1<-t2<-t3<-t4
-      Conflicting transactions: INSERT t1 and DROP TABLE t4
-      Wsrep certification keys taken on write node:
-      - for INSERT t1: t1 and t2
-      - for DROP TABLE t4: t4
-      On applier node MDL deadlock happened between two transaction because
-      MDL locks for INSERT t1 were taken on t1, t2, t3 and t4, which conflicted
-      with MDL lock on t4 taken by DROP TABLE t4.
-      The Wsrep certification keys does helps in resolving in transactions
-      getting MDL deadlock. But to generate Wsrep certification keys it needs
-      to open and take MDL locks on all child tables. So that conflicting
-      transactions can be prioritize and scheduled.
-    */
-    if (WSREP(thd) && !thd->wsrep_applier &&
-        wsrep_is_active(thd) &&
-        (sql_command_flags[thd->lex->sql_command] & CF_INSERTS_DATA)) {
-      override_fk_ignore_table= TRUE;
-    }
-#endif // WITH_WSREP
-
   while ((fk= fk_list_it++))
   {
     // FK_OPTION_RESTRICT and FK_OPTION_NO_ACTION only need read access
@@ -5177,15 +5136,13 @@ prepare_fk_prelocking_list(THD *thd, Query_tables_list *prelocking_ctx,
         TABLE_LIST::PRELOCK_FK,
         table_list->belong_to_view, op,
         &prelocking_ctx->query_tables_last,
-        table_list->for_insert_data,
-        override_fk_ignore_table);
+        table_list->for_insert_data);
 
 #ifdef WITH_WSREP
     /*
       Append table level shared key for the referenced/foreign table for:
         - statement that updates existing rows (UPDATE, multi-update)
         - statement that deletes existing rows (DELETE, DELETE_MULTI)
-	- statement that inserts new rows (INSERT, REPLACE, LOAD, ALTER TABLE)
       This is done to avoid potential MDL conflicts with concurrent DDLs.
     */
     if (wsrep_foreign_key_append(thd, fk))