Deployment Groups

Deployment Groups are a new feature in Payara Server 5. The Deployment Group is designed to replace the deployment targeting aspect of Clusters that was available in previous versions of Payara.

For more information about Deployment Groups in Payara Server 5, read our blog articles on this topic:

Why replace Clusters

A Cluster in Payara Server 4 encapsulated a number of concepts;

  • First it was a target of deployment

  • Second it provided in-memory data storage for web sessions and Stateful Session Beans

  • Third it defined a configuration

  • Fourth it treated a number of Payara Server Instances as a single grouping

With the introduction of the Domain Data Grid the concept of data persistence was split from the Cluster concept to allow all instances to automatically cluster and share data. The introduction of the deployment group splits out the targeting aspect of clusters.

What is a Deployment Group

A Deployment Group is a loose grouping of Payara Server instances that can be used as a target for deployments. Deployment Groups consist of 1 or more Payara Server instances and each Payara Server Instance can belong to one or more Deployment Groups.

Deployment Groups can also be used to manage the lifecycle of the instances in the group. All instances can be started, re-started and stopped using the deployment group. Restarting all the instances in the deployment group performs a rolling restart whereby each instance is restarted in turn to ensure that any data grid held data is retained across the group restart.

Creating a Deployment Group

A deployment group can be created in both the administration console and via Asadmin

Using the Administration console

To create a new deployment group. Navigate to the Deployment Groups node in the navigation tree, click on the New button and give the deployment group a unique name. From this screen it is also possible to add a number of new server instances if desired, however it is possible to add existing instances to the group later. Create New Deployment Group

Using asadmin commands

To create a new deployment group run the command;

asadmin> create-deployment-group test

Deleting a Deployment Group

A deployment group can be deleted in both the administration console and via Asadmin.

When you delete a deployment group that has instances within it these instances are not deleted.

Using the Administration Console

To delete a deployment group. Navigate to the group in the console, select it and choose delete. Delete a Deployment Group

Using asadmin commands

To delete a deployment group run the command;

asadmin> delete-deployment-group test

Managing Deployment Group Membership

Adding an instance

When you have an existing standalone instance it can be assigned to a deployment group using the administration console and via asadmin. To add an existing instance to a deployment group. Navigate to the deployment group in the administration Console and then select the instance in the drop down from the Instances tab. Add a Server to a Deployment Group The same can be achieved using the asadmin command;

asadmin> add-instance-to-deployment-group --instance testserver --deploymentgroup test2
An instance can be in many deployment Groups

Removing an Instance

If you want to remove an instance from a deployment group. Navigate to the deployment group, select the instance and choose remove from the "more actions…​" drop down. Remove a Server from a Deployment Group The same can be acheived using the asadmin command.

asadmin> remove-instance-from-deployment-group --instance testserver --deploymentgroup test2

Server Lifecycle Management

A deployment group can also be used to provide lifecycle management to the group of server instances in the deployment group. All servers in the group can be started, stopped and restarted. To do this, navigate to the deployment group and choose "Start Deployment Group", "Stop Deployment Group" or "Restart Deployment Group".

These commands are Data Grid safe and restart the deployment group in such a way as to minimize the danger of Data Grid disruption.

Server Lifecycle Management

The same can be achieved using the asadmin commands;

asadmin> start-deployment-group test2
asadmin> restart-deployment-group test2
asadmin> stop-deployment-group test2

Deploying Applications to a Deployment Group

To deploy an application to a deployment group you just select the deployment group name in the list of targets in the usual way. This can be done both on the Applications tab of the Deployment Group or on the Applications section of the administration console.

Deploy to a deployment group

To deploy an application using asadmin just specify the deployment group as a target when running the deploy command.

asadmin> deploy --target test2 test.war
The same targeting also works for resources.