MDEV-17262: mysql crashed on galera while node rejoined cluster (#895)

This patch contains a fix for the MDEV-17262/17243 issues and
new mtr test.

These issues (MDEV-17262/17243) have two reasons:

1) After an intermediate commit, a transaction loses its status
of "transaction that registered in the MySQL for 2pc coordinator"
(in the InnoDB) due to the fact that since version 10.2 the
write_row() function (which located in the ha_innodb.cc) does
not call trx_register_for_2pc(m_prebuilt->trx) during the processing
of split transactions. It is necessary to restore this call inside
the write_row() when an intermediate commit was made (for a split
transaction).

Similarly, we need to set the flag of the started transaction
(m_prebuilt->sql_stat_start) after intermediate commit.

The table->file->extra(HA_EXTRA_FAKE_START_STMT) called from the
wsrep_load_data_split() function (which located in sql_load.cc)
will also do this, but it will be too late. As a result, the call
to the wsrep_append_keys() function from the InnoDB engine may be
lost or function may be called with invalid transaction identifier.

2) If a transaction with the LOAD DATA statement is divided into
logical mini-transactions (of the 10K rows) and binlog is rotated,
then in rare cases due to the wsrep handler re-registration at the
boundary of the split, the last portion of data may be lost. Since
splitting of the LOAD DATA into mini-transactions is technical,
I believe that we should not allow these mini-transactions to fall
into separate binlogs. Therefore, it is necessary to prohibit the
rotation of binlog in the middle of processing LOAD DATA statement.

https://jira.mariadb.org/browse/MDEV-17262 and
https://jira.mariadb.org/browse/MDEV-17243

1 files changed, 6 insertions, 0 deletions

diff --git a/sql/wsrep_dummy.cc b/sql/wsrep_dummy.cc
index 7297dbfe0fd..aff75cf7790 100644
--- a/sql/wsrep_dummy.cc
+++ b/sql/wsrep_dummy.cc
@@ -133,6 +133,12 @@ void wsrep_thd_auto_increment_variables(THD *thd,
   *increment= thd->variables.auto_increment_increment;
 }
 
+void wsrep_set_load_multi_commit(THD *thd, bool split)
+{ }
+
+bool wsrep_is_load_multi_commit(THD *thd)
+{ return false; }
+
 int wsrep_trx_is_aborting(THD *)
 { return 0; }