Supported configurations Questions and Answers

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In what cases is IHS use licensed/supported?

The answer depends on how you obtained IHS.

  1. If you acquire IHS bundled with an IBM product, then only the components of IHS used in conjunction with that product are supported. Further, these components are only supported when used according to the recommendations and documentation of that product.
  2. If you acquire IHS via the free web download, no support is provided for any use.
  3. If you acquire IHS from the z/OS "ported tools" product, or as part of the z/OS operating system (V2R2 and later) then IHS is licensed and supported for any use.

Under some circumstances, your sales representative may be able to arrange for "standalone support" of IBM HTTP Server, which carries detailed terms and conditions.

When another vendor lists IBM HTTP Server as a "supported webserver", this is a statement of their own support position in terms of interoperability, and has no bearing on entitlement to support with IBM.

Can I use the IBM HTTP Server proxy feature (mod_proxy)?

Sometimes, people refer to the capability provided by the WAS WebServer Plug-in as "reverse proxy". We're not addressing that here, as it's almost always a supported configuration. This section refers to using mod_proxy with IHS.

Finally, customers using Proxy functionality are encouraged to move to IHS 7.0 or later if possible. This is partially due to the higher quality proxy support in Apache 2.2.x and partially due to IHS 7.0 being more recently "rebased" then previous releases.

What's a recommended HTTP proxy server?

IBM develops, tests, and supports IBM HTTP Server as webserver solution, with the WebSphere Plugin as a specialized form of proxy. There is no investment in the generic HTTP Proxy server (mod_proxy). Other dedicated HTTP proxy serves will often be a better fit when the proxy usage isn't some small amount of "glue" in an otherwise IHS+Plugin WAS topology.

Does IHS support my virtualization technology of choice?

IHS is supported on any virtualization technology that runs a supported, unmodified, operating system. We assume any usage question or defect report is virtualization-agnostic until evidence shows otherwise, and won't ask customers to recreate an issue natively unless we suspect the problem is unique to the virtualization environment.

Technote #1242532 formally covers the virtualization policy for WebSphere Application Server (including IHS).

We don't have any tips for the tuning the guest or hypervisor for IHS.

What support implications are there around FastCGI / mod_fastcgi?

IHS includes a module, mod_fastcgi, that allows proxying requests to an application that speaks the FastCGI protocol. A typical FastCGI application resembles the combination of a basic (non-websphere) application server environment plus a users own application written to that servers programming model.

A common example is a PHP or Perl application sitting on top of a PHP or Perl web development frameork

This module was originally included in IHS when IHS was developed as a standalone commercial webserver. For many years, IHS has been provided only as a reusable component within IBM products (WebSphere Application Server, for example). When IHS is included this way it is only supported when used in a direct and necessary way for the combined product.

For this reason, mod_fastcgi is generally not part of a supported configuration for products that bundle IHS. Customer and product support are only available for supported configurations. While the interpetation of "direct and necessary" is not always clear, IBM support considers cases where the FastCGI usage is clearly in lieu of using the preferred programming language/model/runtime of the product (such as using PHP for pieces of a web application that would otherwise be implemented in Websphere Application Server)

See #SUPPORTED for more details about how IHS is provided in IBM products, and #PROXY for more information on a similar, but less black-and-white, support issue.