MariaDB Galera Cluster has several limitations by design. The developers and the DBA should be aware that some of the features provided by standalone MariaDB servers are not available for the Galera nodes.

First, as we mentioned earlier, Linux is the only operating system supported by Galera.

Galera is designed to be used with the InnoDB storage engine. An experimental support for MyISAM is available but disabled by default. To enable it, the wsrep_replicate_myisam server variable must be set to 1. The Galera team discourages its use in production environments. No other storage engines can be used with Galera.

The binary log must be enabled and its format must be ROW. Statement-based or mixed replication isn't supported.

Statements that acquire explicit locks, such as SELECT … FOR UPDATE, SELECT … LOCK IN SHARE MODE, LOCK TABLES, or FLUSH TABLES … FOR EXPORT are not supported. This makes the use of MyISAM even less desirable. The SERIALIZABLE isolation level, which turns all plain queries into locking queries, is not supported either. The reason being that read operations and locks are not propagated over the cluster. So the locks are only acquired on one node, causing potential conflicts. There is an exception: if all the clients connect to the same node, the locks are safe.

Galera is designed to replicate tables that have a primary key. Various problems may occur with tables that don't have an explicit primary key, for example, DELETE will not be supported, XA transactions will not be supported, the InnoDB double write buffer will be disabled, and the query cache will not be supported.

Statements that explicitly modify a table in the mysql database are not supported. The general query log and error log, if enabled, cannot be written into system tables.