In Percona Server 5.6, we introduced: https://www.percona.com/doc/percona-server/5.6/scalability/multiple_user_level_locks.html#multiple-user-level-locks living now in MDL context, the same way as it is in MySQL 5.7 now: http://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
The function *mysql_ull_cleanup* we can see in stack traces is not even present in MySQL Community 5.6: $ grep -r 'mysql_ull_cleanup' mysql-5.6.30/
$ grep -r 'mysql_ull_cleanup' mysql-5.7.12/ mysql-5.7.12/sql/item_func.h:void mysql_ull_cleanup(THD *thd); mysql-5.7.12/sql/item_func.cc:void mysql_ull_cleanup(THD *thd) mysql-5.7.12/sql/item_func.cc: DBUG_ENTER("mysql_ull_cleanup"); mysql-5.7.12/sql/sql_class.cc: mysql_ull_cleanup(this);
$ grep -r 'mysql_ull_cleanup' Percona-XtraDB-Cluster-5.6.27-76.0/ Percona-XtraDB-Cluster-5.6.27-76.0/sql/item_func.h:void mysql_ull_cleanup(THD *thd); Percona-XtraDB-Cluster-5.6.27-76.0/sql/wsrep_thd.cc: mysql_ull_cleanup(thd); Percona-XtraDB-Cluster-5.6.27-76.0/sql/item_func.cc:void mysql_ull_cleanup(THD *thd) Percona-XtraDB-Cluster-5.6.27-76.0/sql/item_func.cc: DBUG_ENTER("mysql_ull_cleanup"); Percona-XtraDB-Cluster-5.6.27-76.0/sql/sql_class.cc: mysql_ull_cleanup(this);
So in addition to the fact that user locks are not supported in Galera: http://galeracluster.com/documentation-webpages/limitations.html#table-locking https://blueprints.launchpad.net/codership-mysql/+spec/get-lock-support
now they are even more complex in PXC 5.6.19+, which I think may lead to those crashes.
In Percona Server 5.6, we introduced: /www.percona. com/doc/ percona- server/ 5.6/scalability /multiple_ user_level_ locks.html# multiple- user-level- locks dev.mysql. com/doc/ refman/ 5.7/en/ miscellaneous- functions. html#function_ get-lock
https:/
living now in MDL context, the same way as it is in MySQL 5.7 now:
http://
The function *mysql_ull_cleanup* we can see in stack traces is not even present in MySQL Community 5.6:
$ grep -r 'mysql_ull_cleanup' mysql-5.6.30/
$ grep -r 'mysql_ull_cleanup' mysql-5.7.12/ 7.12/sql/ item_func. h:void mysql_ull_ cleanup( THD *thd); 7.12/sql/ item_func. cc:void mysql_ull_ cleanup( THD *thd) 7.12/sql/ item_func. cc: DBUG_ENTER( "mysql_ ull_cleanup" ); 7.12/sql/ sql_class. cc: mysql_ull_ cleanup( this);
mysql-5.
mysql-5.
mysql-5.
mysql-5.
$ grep -r 'mysql_ull_cleanup' Percona- XtraDB- Cluster- 5.6.27- 76.0/ XtraDB- Cluster- 5.6.27- 76.0/sql/ item_func. h:void mysql_ull_ cleanup( THD *thd); XtraDB- Cluster- 5.6.27- 76.0/sql/ wsrep_thd. cc: mysql_ull_ cleanup( thd); XtraDB- Cluster- 5.6.27- 76.0/sql/ item_func. cc:void mysql_ull_ cleanup( THD *thd) XtraDB- Cluster- 5.6.27- 76.0/sql/ item_func. cc: DBUG_ENTER( "mysql_ ull_cleanup" ); XtraDB- Cluster- 5.6.27- 76.0/sql/ sql_class. cc: mysql_ull_ cleanup( this);
Percona-
Percona-
Percona-
Percona-
Percona-
So in addition to the fact that user locks are not supported in Galera: galeracluster. com/documentati on-webpages/ limitations. html#table- locking /blueprints. launchpad. net/codership- mysql/+ spec/get- lock-support
http://
https:/
now they are even more complex in PXC 5.6.19+, which I think may lead to those crashes.