Create and updating a gateway cluster

In order to improve performance and availability, you configure WebSphere Application Server so that a set of appservers acts as a cluster. In a cluster, several appservers are configured identically, and a plug-in to the front-end HTTP server shares incoming HTTP requests between the available application servers in the cluster. Application servers in a cluster can each be hosted on a separate machine, or all hosted on one or two machines. For a more detailed overview of options for clustering in WebSphere Application Server Network Deployment, see Setting up a multinode environment.

To create a gateway cluster, you manually install an identically-configured gateway on every application server in an existing cluster.

To create and update a gateway cluster, complete the following steps:

 

  1. Create a cluster of appservers. For example, by completing the following substeps:

    Note: These substeps illustrate how to use the WebSphere Application Server Network Deployment deployment manager and administrative console to create a two-server cluster within a cell. In this example, each clustered appserver is on a separate node of the cell. However there are other valid configurations, and other ways of creating a cluster. For more detailed information see the  

     

    InfoCenter for WebSphere Application Server Edge components , which contains complete documentation for the Caching Proxy and the Load Balancer in the following PDF online books: WebSphere Application Server Concepts, Planning, and Installation for Edge Components; the WebSphere Application Server Caching Proxy Administration Guide, and the WebSphere Application Server Programming Guide for Edge Components.

    1. Install WebSphere Application Server on machines X and Y.

    2. Install WebSphere Application Server Network Deployment on machine X.

    3. Stop all appservers on both machines.

    4. Add machines X and Y as nodes in a deployment manager cell by entering the following command from a command line on each machine: 

      WAS_HOME/bin/addnode dm_machine_hostname dm_port -includeapps

      where

      • WAS_HOME is the root directory of your target appserver (by default WebSphere/AppServer).

      • dm_machine_hostname is the host name for the machine on which the deployment manager for this cell is running (in this case machine X).

      • dm_port is the port on which the deployment manager is listening (by default 8879 ).
      For example (Windows systems): 

      C:\Progra~1\WebSphere\AppServer\bin\addnode xhost 8879 -includeapps

    5. Use the WebSphere Application Server Network Deployment administrative console to create new, clustered appservers on the two machines:

      1. Select Servers -> Clusters -> New.

      2. Enter a name for the cluster.

      3. Clear the Prefer local enabled check box.

      4. Select the Do not include an existing server in this cluster check box.

      5. Create a new clustered appserver on machine X (enter a name for the appserver; select the node for this application server (machine X); clear the generate unique HTTP Ports check box; click Apply).

      6. Repeat the previous step to create a new clustered appserver on machine Y.

      7. Click Next.

      8. Click Finish.

    The new cluster is created.

  2. Install a gateway on every appserver in the cluster.

  3. Select and configure the gateway that is to be the source configuration for every gateway in the cluster.

    Note:

    • The gateway that is chosen as the source for the cluster configuration need not be part of the cluster.

    • The channels deployed to this gateway must have their End Point addresses configured for clustering. See Deploying channels to the Web services gateway.

  4. Use the back up and restore options to save the source configuration, then restore it to every gateway in the cluster.

  5. Apply all subsequent gateway updates only to the source configuration gateway, then use the back up and restore options to restore the updated configuration to every gateway in the cluster.

    Note: This is particularly important with regard to Web services that have been published to UDDI by the gateway. When you save a gateway configuration, the record of which Web services have been gateway-published to UDDI is not saved (for reason that are explained in Backing up and restoring UDDI publication links). So if you change the gateway that you use as the source for cluster updates, you lose the record of which Web services have been gateway-published to UDDI.

Backing up and restoring UDDI publication links
Backing up and restoring a gateway configuration

 

WebSphere is a trademark of the IBM Corporation in the United States, other countries, or both.

 

IBM is a trademark of the IBM Corporation in the United States, other countries, or both.