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Limitations of MySQL sync clusters with replicas
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Limitations of MySQL sync clusters with replicas

MySQL sync clusters with replicas are subject to restrictions:

  • replication works only with the InnoDB storage subsystem ( MyISAM is not supported);
  • ALTER TABLE may cause the cluster to stop — we recommend using the the pt-online-schema-change utility;
  • LOCK/UNLOCK, GET_LOCK()/RELEASE_LOCK() requests are not supported;
  • all tables must have a primary key — otherwise it is impossible to make an INSERT record;
  • XA transactions are not supported due to a possible ROLLBACK during the COMMIT phase;
  • transaction can rollback even after COMMIT — out of two transactions modifying the same record on different nodes, only one will be successfully completed and the other will be aborted at the cluster level;
  • When naming temporary tables, do not use names that match the names of permanent tables — such a match will stop replication of the permanent table.

Learn more about the limitations in the official Percona XtraDB Cluster documentation.