Bug#1421360: Add 'FLUSH TABLES' to Total Order Isolation execution.

Before this, FLUSH TABLES and FLUSH TABLES t1 (REFRESH_TABLES hereafter) were executed locally,
which also had implications for GTID. MySQL async replication does
replicate FLUSH TABLES.

Hence, this commit

a)  Adds REFRESH_TABLES to TOI.

b) Skips LOCK-based REFRESH_TABLES from TOI, ie. FLUSH TABLES WITH READ
LOCK and FLUSH TABLES FOR EXPORT.

c) Executes them after reload_acl_and_cache. This is done since
reload_acl_and_cache checks for thd->locked_tables_mode and does upgrade
of MDL locks accordingly. A failure here means REFRESH_TABLES cannot
run.

    i) This is also important since LOCK TABLES is not replicated in
    galera.

d) Test galera_flush has been modified for

    i) wsrep_replicate_myisam SESSION variable.

    ii) Testing REFRESH_TABLES.

    iii) Testing REFRESH_TABLES + LOCK TABLES.

e) Use different WSREP_TO_ISOLATION_BEGIN for global FLUSH TABLES and FLUSH TABLES <table,>.

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

@@ -8,7 +8,7 @@ SET GLOBAL wsrep_replicate_myisam = TRUE;
 INSERT INTO mysql.user VALUES('localhost','user1',PASSWORD('pass1'), 'Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','','','','',0,0,0,0,'mysql_native_password','','N','N');
 FLUSH PRIVILEGES;
 DELETE FROM mysql.user WHERE user = 'user1';
-SET GLOBAL wsrep_replicate_myisam = FALSE;
+SET SESSION wsrep_replicate_myisam = FALSE;
 FLUSH PRIVILEGES;
 FLUSH QUERY CACHE;
 wsrep_last_committed_diff
@@ -19,6 +19,13 @@ wsrep_last_committed_diff
 FLUSH USER_RESOURCES;
 wsrep_last_committed_diff
 1
+FLUSH TABLES;
+wsrep_last_committed_diff
+1
+CREATE TABLE t2 (f1 INTEGER);
+FLUSH TABLES t2;
+wsrep_last_committed_diff
+1
 CREATE TABLE t1 (f1 INTEGER);
 FLUSH LOGS;
 FLUSH TABLES WITH READ LOCK;
@@ -29,4 +36,19 @@ FLUSH TABLES t1 FOR EXPORT;
 UNLOCK TABLES;
 wsrep_last_committed_diff
 1
+LOCK TABLES t1 WRITE;
+FLUSH TABLES t1;
+UNLOCK TABLES;
+wsrep_last_committed_diff
+1
+LOCK TABLES t1 READ;
+FLUSH TABLES t1;
+ERROR HY000: Table 't1' was locked with a READ lock and can't be updated
+UNLOCK TABLES;
+wsrep_last_committed_diff
+1
+FLUSH TABLES t1;
+wsrep_last_committed_diff
+1
 DROP TABLE t1;
+DROP TABLE t2;

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

@@ -39,7 +39,7 @@ FLUSH PRIVILEGES;
 --connect node_2a, 127.0.0.1, user1, pass1, test, $NODE_MYPORT_2
 --connection node_1
 DELETE FROM mysql.user WHERE user = 'user1';
-SET GLOBAL wsrep_replicate_myisam = FALSE;
+SET SESSION wsrep_replicate_myisam = FALSE;
 FLUSH PRIVILEGES;
 
 
@@ -77,8 +77,32 @@ FLUSH USER_RESOURCES;
 --enable_query_log
 
 
+--connection node_2
+--let $wsrep_last_committed_before = `SELECT VARIABLE_VALUE FROM INFORMATION_SCHEMA.SESSION_STATUS WHERE VARIABLE_NAME = 'wsrep_last_committed'`
+--connection node_1
+FLUSH TABLES;
+--connection node_2
+--let $wsrep_last_committed_after = `SELECT VARIABLE_VALUE FROM INFORMATION_SCHEMA.SESSION_STATUS WHERE VARIABLE_NAME = 'wsrep_last_committed'`
+--disable_query_log
+--eval SELECT $wsrep_last_committed_after = $wsrep_last_committed_before + 1 AS wsrep_last_committed_diff;
+--enable_query_log
+
+--connection node_1
+CREATE TABLE t2 (f1 INTEGER);
+
+--connection node_2
+--let $wsrep_last_committed_before = `SELECT VARIABLE_VALUE FROM INFORMATION_SCHEMA.SESSION_STATUS WHERE VARIABLE_NAME = 'wsrep_last_committed'`
+--connection node_1
+FLUSH TABLES t2;
+--connection node_2
+--let $wsrep_last_committed_after = `SELECT VARIABLE_VALUE FROM INFORMATION_SCHEMA.SESSION_STATUS WHERE VARIABLE_NAME = 'wsrep_last_committed'`
+--disable_query_log
+--eval SELECT $wsrep_last_committed_after = $wsrep_last_committed_before + 1 AS wsrep_last_committed_diff;
+--enable_query_log
+
+
 #
-# The following statements should not be replicated: FLUSH LOGS, FLUSH TABLES
+# The following statements should not be replicated: FLUSH LOGS, FLUSH TABLES WITH LOCKS
 #
 
 
@@ -103,5 +127,47 @@ UNLOCK TABLES;
 --eval SELECT $wsrep_last_committed_after = $wsrep_last_committed_before AS wsrep_last_committed_diff;
 --enable_query_log
 
+
+## Test LOCK TABLES with FLUSH TABLES
+## LOCK TABLES t1 write followed by flush tables t1 should succeed due to MDL upgrade.
+## LOCK tables t2 read followed by flush tables t2 should fail with ER_TABLE_NOT_LOCKED_FOR_WRITE
+
+
+--connection node_2
+--let $wsrep_last_committed_before = `SELECT VARIABLE_VALUE FROM INFORMATION_SCHEMA.SESSION_STATUS WHERE VARIABLE_NAME = 'wsrep_last_committed'`
+--connection node_1
+LOCK TABLES t1 WRITE;
+FLUSH TABLES t1;
+UNLOCK TABLES;
+--connection node_2
+--let $wsrep_last_committed_after = `SELECT VARIABLE_VALUE FROM INFORMATION_SCHEMA.SESSION_STATUS WHERE VARIABLE_NAME = 'wsrep_last_committed'`
+--disable_query_log
+--eval SELECT $wsrep_last_committed_after = $wsrep_last_committed_before + 1 AS wsrep_last_committed_diff;
+--enable_query_log
+
+
+--connection node_2
+--let $wsrep_last_committed_before = `SELECT VARIABLE_VALUE FROM INFORMATION_SCHEMA.SESSION_STATUS WHERE VARIABLE_NAME = 'wsrep_last_committed'`
+--connection node_1
+LOCK TABLES t1 READ;
+--error ER_TABLE_NOT_LOCKED_FOR_WRITE
+FLUSH TABLES t1;
+UNLOCK TABLES;
+--connection node_2
+--let $wsrep_last_committed_after = `SELECT VARIABLE_VALUE FROM INFORMATION_SCHEMA.SESSION_STATUS WHERE VARIABLE_NAME = 'wsrep_last_committed'`
+--disable_query_log
+--eval SELECT $wsrep_last_committed_after = $wsrep_last_committed_before AS wsrep_last_committed_diff;
+--enable_query_log
+--connection node_1
+FLUSH TABLES t1;
+--connection node_2
+--let $wsrep_last_committed_after = `SELECT VARIABLE_VALUE FROM INFORMATION_SCHEMA.SESSION_STATUS WHERE VARIABLE_NAME = 'wsrep_last_committed'`
+--disable_query_log
+--eval SELECT $wsrep_last_committed_after = $wsrep_last_committed_before + 1 AS wsrep_last_committed_diff;
+--enable_query_log
+
+
+
 --connection node_1
 DROP TABLE t1;
+DROP TABLE t2;

sql/sql_parse.cc

@@ -4695,6 +4695,25 @@ case SQLCOM_PREPARE:
     */
     if (!reload_acl_and_cache(thd, lex->type, first_table, &write_to_binlog))
     {
+#ifdef WITH_WSREP
+      if ((lex->type & REFRESH_TABLES) && !(lex->type & (REFRESH_FOR_EXPORT|REFRESH_READ_LOCK)))
+      {
+        /*
+          This is done after reload_acl_and_cache is because
+          LOCK TABLES is not replicated in galera, the upgrade of which
+          is checked in reload_acl_and_cache.
+          Hence, done after/if we are able to upgrade locks.
+        */
+        if (first_table)
+        {
+            WSREP_TO_ISOLATION_BEGIN(NULL, NULL, first_table);
+        }
+        else
+        {
+            WSREP_TO_ISOLATION_BEGIN(WSREP_MYSQL_DB, NULL, NULL);
+        }
+      }
+#endif /* WITH_WSREP */
       /*
         We WANT to write and we CAN write.
         ! we write after unlocking the table.