Re: [Maria-developers] MDEV-5914

21 Mar 2014

Jan Lindström  writes:
...
Here is necessary changes. I have run whole mysql-test-run and I did not see
any failures, thus is is mostly safe. I say mostly,
because we really do not have much test cases that would use multimaster setup
and try to get conflicting transactions
generated from local clients against slave thread.
Thanks a lot!

I will try to come up with some test cases for this, with replication and
external transactions that conflict and show the problem.

In parallel, I tried running the parallel replication slaves with READ
COMMITTED; that also seems to work and can get Elena able to continue
testing. But this change is potentially more correct; I will let you know when
I have some test results.

 - Kristian.
...
=================================
jan@jan-GE70-0NC-0ND ~/mysql/10.0-mdev5914 $ bzr diff
=== modified file 'include/mysql/plugin.h'

--- include/mysql/plugin.h    2014-02-26 14:28:07 +0000
+++ include/mysql/plugin.h    2014-03-21 09:05:58 +0000
@@ -617,6 +617,7 @@
 int thd_in_lock_tables(const MYSQL_THD thd);
 int thd_tablespace_op(const MYSQL_THD thd);
 long long thd_test_options(const MYSQL_THD thd, long long test_options);
+unsigned long long thd_group_commit_id(const MYSQL_THD thd);
 int thd_sql_command(const MYSQL_THD thd);
 void **thd_ha_data(const MYSQL_THD thd, const struct handlerton *hton);
 void thd_storage_lock_wait(MYSQL_THD thd, long long value);
=== modified file 'include/mysql/plugin_audit.h.pp'
--- include/mysql/plugin_audit.h.pp    2013-12-22 16:11:20 +0000
+++ include/mysql/plugin_audit.h.pp    2014-03-21 09:06:17 +0000
@@ -298,6 +298,7 @@
 int thd_in_lock_tables(const void* thd);
 int thd_tablespace_op(const void* thd);
 long long thd_test_options(const void* thd, long long test_options);
+unsigned long long thd_group_commit_id(const void* thd);
 int thd_sql_command(const void* thd);
 void **thd_ha_data(const void* thd, const struct handlerton *hton);
 void thd_storage_lock_wait(void* thd, long long value);
=== modified file 'include/mysql/plugin_auth.h.pp'
--- include/mysql/plugin_auth.h.pp    2013-12-22 16:11:20 +0000
+++ include/mysql/plugin_auth.h.pp    2014-03-21 09:06:35 +0000
@@ -298,6 +298,7 @@
 int thd_in_lock_tables(const void* thd);
 int thd_tablespace_op(const void* thd);
 long long thd_test_options(const void* thd, long long test_options);
+unsigned long long thd_group_commit_id(const void* thd);
 int thd_sql_command(const void* thd);
 void **thd_ha_data(const void* thd, const struct handlerton *hton);
 void thd_storage_lock_wait(void* thd, long long value);
=== modified file 'include/mysql/plugin_ftparser.h.pp'
--- include/mysql/plugin_ftparser.h.pp    2013-12-22 16:11:20 +0000
+++ include/mysql/plugin_ftparser.h.pp    2014-03-21 09:06:59 +0000
@@ -251,6 +251,7 @@
 int thd_in_lock_tables(const void* thd);
 int thd_tablespace_op(const void* thd);
 long long thd_test_options(const void* thd, long long test_options);
+unsigned long long thd_group_commit_id(const void* thd);
 int thd_sql_command(const void* thd);
 void **thd_ha_data(const void* thd, const struct handlerton *hton);
 void thd_storage_lock_wait(void* thd, long long value);
=== modified file 'sql/sql_class.cc'
--- sql/sql_class.cc    2014-03-20 14:36:45 +0000
+++ sql/sql_class.cc    2014-03-21 09:07:12 +0000
@@ -675,6 +675,12 @@
 }
extern "C"
+unsigned long long thd_group_commit_id(const THD *thd)
+{
+  return thd->rpl_group_commit_id;
+}
+
+extern "C"
 int thd_sql_command(const THD *thd)
 {
   return (int) thd->lex->sql_command;
=== modified file 'storage/innobase/handler/ha_innodb.cc'
--- storage/innobase/handler/ha_innodb.cc    2014-02-26 18:36:33 +0000
+++ storage/innobase/handler/ha_innodb.cc    2014-03-20 15:42:27 +0000
@@ -2048,6 +2048,8 @@
     trx->check_unique_secondary = !thd_test_options(
         thd, OPTION_RELAXED_UNIQUE_CHECKS);
+    trx->group_commit_id = thd_group_commit_id(thd);
+
     DBUG_VOID_RETURN;
 }
=== modified file 'storage/innobase/include/trx0trx.h'
--- storage/innobase/include/trx0trx.h    2014-02-26 18:36:33 +0000
+++ storage/innobase/include/trx0trx.h    2014-03-20 15:28:19 +0000
@@ -840,6 +840,7 @@
                     or the state last time became
                     TRX_STATE_ACTIVE */
     trx_id_t    id;        /*!< transaction id */
+    ib_uint64_t    group_commit_id;/*!< Group commit id or 0 */
     XID        xid;        /*!< X/Open XA transaction
                     identification to identify a
                     transaction branch */
=== modified file 'storage/innobase/lock/lock0lock.cc'
--- storage/innobase/lock/lock0lock.cc    2014-02-26 18:22:48 +0000
+++ storage/innobase/lock/lock0lock.cc    2014-03-21 09:32:54 +0000
@@ -1020,6 +1020,23 @@
             return(FALSE);
         }
+        if (trx->group_commit_id != 0 &&
+            lock2->trx->group_commit_id != 0 &&
+            trx->group_commit_id == lock2->trx->group_commit_id &&
+            (type_mode & LOCK_GAP || lock_rec_get_gap(lock2))) {
+            /* No lock request needs to wait GAP locks if
+            transactions belong to the same group commit group.
+            This is because we have already verified these
+            transactions on master that they do not conflict
+            on record locks but as they could be executed on
+            different order on slave we should not wait for
+            gap locks here. Note that parallel replication
+            makes sure that transaction commits are executed
+            in the same order in master and slave. */
+
+            return (FALSE);
+        }
+
         return(TRUE);
     }
=== modified file 'storage/xtradb/handler/ha_innodb.cc'
--- storage/xtradb/handler/ha_innodb.cc    2014-02-26 18:21:23 +0000
+++ storage/xtradb/handler/ha_innodb.cc    2014-03-20 15:42:41 +0000
@@ -2308,6 +2308,8 @@
trx->fake_changes = THDVAR(thd, fake_changes);
+    trx->group_commit_id = thd_group_commit_id(thd);
+
 #ifdef EXTENDED_SLOWLOG
     if (thd_log_slow_verbosity(thd) & (1ULL << SLOG_V_INNODB)) {
         trx->take_stats = TRUE;
=== modified file 'storage/xtradb/include/trx0trx.h'
--- storage/xtradb/include/trx0trx.h    2014-02-26 18:21:23 +0000
+++ storage/xtradb/include/trx0trx.h    2014-03-20 15:28:20 +0000
@@ -861,6 +861,7 @@
                     or the state last time became
                     TRX_STATE_ACTIVE */
     trx_id_t    id;        /*!< transaction id */
+    ib_uint64_t    group_commit_id;/*!< Group commit id or 0 */
     XID        xid;        /*!< X/Open XA transaction
                     identification to identify a
                     transaction branch */
=== modified file 'storage/xtradb/lock/lock0lock.cc'
--- storage/xtradb/lock/lock0lock.cc    2013-12-22 16:06:50 +0000
+++ storage/xtradb/lock/lock0lock.cc    2014-03-21 09:32:46 +0000
@@ -1021,6 +1021,23 @@
             return(FALSE);
         }
+        if (trx->group_commit_id != 0 &&
+            lock2->trx->group_commit_id != 0 &&
+            trx->group_commit_id == lock2->trx->group_commit_id &&
+            (type_mode & LOCK_GAP || lock_rec_get_gap(lock2))) {
+            /* No lock request needs to wait GAP locks if
+            transactions belong to the same group commit group.
+            This is because we have already verified these
+            transactions on master that they do not conflict
+            on record locks but as they could be executed on
+            different order on slave we should not wait for
+            gap locks here. Note that parallel replication
+            makes sure that transaction commits are executed
+            in the same order in master and slave. */
+
+            return (FALSE);
+        }
+
         return(TRUE);
     }

    

Re: [Maria-developers] MDEV-5914

Kristian Nielsen