Starting New Grid Nodes (Application Instances)

Application instances are started by launching a binding that targets the correct node type. Normally you do not start individual application nodes. Instead, you start an entire application and, as a result, all nodes belonging to the application will be started. However, there are situations when you want to start an individual application node. Examples are:

  • An application is experiencing increased load and you want to start a new server application instance, perhaps on a new host with spare capacity, in order to cope with the new situation.

  • You intend to stop an existing node and you want to start a new alternative node first so that the operations of the application will not be disturbed when you stop the node.

  • You want to move the execution of this application from one host to another. This would be done by starting new nodes on the new host combined with stopping the old nodes on the original host. Note that not all applications support this operation. Consult the documentation for the application.

Considerations before Starting a Node:

  • Does the application support manually starting new nodes? Some applications manage their own nodes and they should not be started manually.

  • Some applications do not support several instances running simultaneously. If that is the case with the application you are starting, existing nodes may have to be stopped first. However, ideally, applications should be written to support this.

  • Always consult the application's documentation on what is supported in each case.

To start grid nodes

  1. Navigate to the Topology View page in the Grid Management pages.
  2. In the list, each host has a start button. Click the start button for the host that you want the new node to run on.
  3. In the dialog box, select the binding you want to start.

What If the Binding to Start Does Not Appear in the Dialog Box?

The typical reasons for not finding a particular binding when trying to launch it on a host are:

  • The binding is not configured to be able to run on that host.

  • The binding is configured to allow a maximum number of simultaneously running nodes of this type and that maximum number of nodes is already running in the grid.

    For information on configuring bindings, see Configuring bindings.