Scaling the Web services gateway using unlocked configuration deployment
You scale the gateway by installing an identical gateway on several appservers to create a scaling group, then using a plug-in to the front-end HTTP server to balance the load across the group.
Overview
![[V5.1]](../../v51.gif)
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.
![[V5.1.1 and later]](../../v511x.gif)
If you are using
the (deprecated) Apache SOAP channel:
- You must use the scaling method described in this topic.
- If any (or all) of the appservers 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.
For more information about the
differences between the two scaling methods, see Web services gateway - the scalability options.
Overview
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:
- 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.
- (Optional)
Add
the nodes for the appservers in the scaling group to a deployment
manager cell.
- Install a gateway on
every appserver in the scaling group.
- 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 appserver 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.
- 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).
- The HTTP channels deployed to this gateway have their
end point addresses configured as either one-part addresses or two-part addresses,
as appropriate for the version of WebSphere Application Server that is used
by the scaling group (for details of applicability, see Web services gateway - the scalability options).
- This gateway is not hosted on an appserver that is part of the
group.
- 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.
- 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 appservers 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.
- WebSphere Application Server Concepts, Planning, and Installation
for Edge Components.
- 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.
Scaling the Web services gateway