[Version 5.0.2 and later]Scaling the Web services gateway using unlocked configuration deployment

You scale the gateway by installing an identical gateway on several application servers to create a scaling group, then using a plug-in to the front-end HTTP server to balance the load across the group.

Before you begin

[Version 5.0.2]If any (or all) of the application servers in your scaling group are hosted on nodes that are members of a deployment manager cell, the cell cannot safely also contain other gateway servers that are not part of the scaling group.

[Version 5.0.2]In the z/OS environment, the gateway technology preview only operates in an application server that has exactly one servant process instance. Therefore the process described here is the only way to achieve load balancing for the gateway technology preview on z/OS.

Why and when to perform this task

You configure an instance of the gateway that is separate from the scaling group, then maintain this gateway as the source configuration for every gateway in the group. You use the back up and restore options to save the source configuration as a Shared configuration, then restore the saved configuration to every gateway in the group.

To scale the gateway using unlocked configuration deployment, complete the following steps:

Steps for this task

  1. Select or create each member of your scaling group of application servers. If you install WebSphere Application Server, include the gateway files in the installed configuration either by accepting the "typical install" option, or by choosing the "custom install" option Web services > Web services gateway.
  2. (Optional)   Add the nodes for the application servers in the scaling group to a deployment manager cell.
  3. Install a gateway on every application server in the scaling group.
  4. Select and configure the gateway that is the source configuration for every gateway in the scaling group.
    Ensure that your source configuration meets the following requirements:
    • This gateway is not hosted on an application server that is part of the group.
    • The WSDL URI for exported definitions is set to indicate the HTTP server that is used by the scaling group.
    • The HTTP channels deployed to this gateway have their end point addresses set to indicate the HTTP server that is used by the scaling group.
    • [Version 5.0.2]The HTTP channels deployed to this gateway have their end point addresses configured as two-part addresses (see Deploying channels to the Web services gateway).
  5. Use the back up and restore options to save the source configuration as a Shared configuration, then restore the saved configuration to every gateway in the scaling group.
  6. Use the WebSphere Application Server Caching Proxy and Load Balancer in the front-end HTTP server to balance the load by sharing incoming HTTP requests among the application servers in the scaling group.
    For detailed information see the information center for WebSphere Application Server Edge components. This information center contains complete documentation for Caching Proxy and Load Balancer in the following PDF online books:
    • WebSphere Application Server Concepts, Planning, and Installation for Edge Components.
    • WebSphere Application Server Caching Proxy Administration Guide.
    • WebSphere Application Server Load Balancer Administration Guide.
    • WebSphere Application Server Programming Guide for Edge Components.
  7. Apply all subsequent gateway updates only to the source configuration gateway.
    This is particularly important with regard to Web services that are published to UDDI by the gateway. When you save a gateway configuration, the record of which Web services are gateway-published to UDDI is not saved (for reasons that are explained in Backing up and restoring UDDI publication links). If you change the gateway that you use as the source for configuration updates, you lose this record.

Related tasks
Scaling the Web services gateway



Searchable topic ID:   twsg_scale_unlock
Last updated: Jun 21, 2007 9:56:50 PM CDT    WebSphere Application Server for z/OS, Version 5.0.2
http://publib.boulder.ibm.com/infocenter/wasinfo/index.jsp?topic=/com.ibm.websphere.zseries.doc/info/zseries/ae/twsg_scale_unlock.html

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