My webMethods Server containers provide a dedicated location /MWS/volumes/configs/cluster_cfg to which you can mount an external volume and supply the initial configuration of a container cluster in a cluster.xml file. You can define the external volume in a Docker Compose template or Kubernetes object descriptor. When the cluster starts, My webMethods Server checks whether the volume, mounted to the /MWS/volumes/configs directory (if present) contains a cluster_cfg and copies the cluster.xml file from the volume to the database for all cluster nodes to access. Cluster nodes continue to use the cluster.xml after cluster restart, and until you supply a new configuration through the volume. You cannot use local cluster.xml files when running a My webMethods Server cluster that consists of Docker containers.

You can modify the initial configuration further, using the Cluster Settings > Advanced or Clustered Configuration > JMS Provider URL > Advanced Settings, for example, to enable SSL communication to the Universal Messaging server that a cluster node uses. Changes that you make in the My webMethods Server web user interface are stored in the MWS/volumes/data directory on the container file system, or the volume mounted to it, and persist after restarting the container. These settings apply per node and override the configuration supplied through the volume, mounted to the/MWS/volumes/configs directory if such volume is available.

To use the /MWS/volumes/configs/cluster_cfg to deploy cluster.xml files, you must mount a volume or a host directory to the MWS/volumes/configs directory, and that volume or host directory must contain a subdirectory with the name cluster_cfg. If you do not mount a volume, or the volume does not include an cluster_cfg directory, the Docker daemon does not create an /MWS/volumes/configs/cluster_cfg subdirectory on the container file system.