If MySQL connections fail, the MySQL JDBC driver tries to repair a connection three times. This results in very delayed fall backs to master if slave is failing.

This reconnection tries is controlled by the autoReconnect parameter for MySQL JDBC connections.

Changing in /opt/open-xchange/etc/configdb.properties the following properties:
readProperty.5=autoReconnect=false
writeProperty.5=autoReconnect=false

This needs to be changed in the provisioning client, too, if the URL for databases is prepared there.

To change this for already registered databases execute the following statement on the configdb:
UPDATE configdb.db_pool SET url=REPLACE(url,'autoReconnect=true','autoReconnec t=false');