Comment 1 for bug 1088400

Extra information: it seems like this is only happening when running queries via PHP. When executing exactly the same set of queries using cat queries.sql | mysql -u root -p -D etc etc nothing goes wrong.

Following packages installed on Ubuntu 12.04 LTS:

percona-xtrabackup
percona-xtradb-cluster-client-5.5
percona-xtradb-cluster-common-5.5
percona-xtradb-cluster-galera-2.x
percona-xtradb-cluster-server-5.5

<guessing>
It looks like this is one of the tables which, when a record is inserted via PHP, causes the crash. We've seen several different queries on which the server crashes, but it looks like it's limited to 3 tables. This is one of them:

CREATE TABLE `CRMentityformcache` (
  `formcacheid` mediumint(9) NOT NULL AUTO_INCREMENT,
  `eid` mediumint(9) NOT NULL,
  `formid` mediumint(9) NOT NULL,
  `tabletype` varchar(15) NOT NULL DEFAULT 'entity',
  `user` mediumint(9) NOT NULL,
  `content` varchar(255) DEFAULT NULL,
  `timestamp_last_change` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`formcacheid`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8 COMMENT='Interleave Cached parsed forms'

Application log show the last query executed which (probably) was directly causing the crash. Again, when executing this on the mysql prompt, all is ok and via PHP this query doesn't ALWAYS crash the server - only about 40-60% of the time (2 to 3 pageloads).

 SQL: ERROR_LAST_QUERY_WENT_WRONG Lost connection to MySQL server during query query : DELETE FROM CRMentityformcache WHERE user='1'

Of course the tables are checked and ok and the software / queries / etc run fine on a stock MySQL server.
</guessing>