FAQ: Support issues

In what cases is IHS use licensed/supported?

The answer depends on how you obtained IHS.

• 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.

  Review the license and documentation of the IBM product for further details.

• If you acquire IHS as part of the z/OS operating system (V2R2 and later) then IHS is licensed and supported for any use.

• If you acquire IHS via the free web download, no support is provided for any use.

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 from IBM.

Unsupported Configurations

1. Use of IHS that is not direct or necessary for the licensed use of the IBM product that includes it is unsupported.

   • Using IHS separately from the IBM product that includes it, even if the separate use runs in the same server as an otherwise supported use.

   • Using IHS in a contradictory or undocumented way in the context of the product that included it.

2. Use of IHS a gateway to any IBM product (such as WebSphere Application Server) when the product runs in kubernetes or openshift. For additionaldetails, including some relatively obscure supported configurations, see openshift

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 using the WAS WebServer Plug-in as a frontend to WAS is an obvious supported configuration of WAS products.

Note: This section refers to using mod_proxy with IHS outside of IHS bundled with z/OS, where IHS is provided as a general purpose webserver.

Supported but not recommended configurations

• An example of a supported reverse proxy usage would be to forward small ranges of the URI-space to another server during a period of migration, or to workaround virtual-host related configuration issues, in a way that complies with all the provisions of this document.

• If an IBM product bundles IBM HTTP Server, they may use mod_proxy in their own supported configurations. In this case, the expectation is that the product team narrowly and explicitly defines, tests, and supports the set of supported configurations. This scenario is very uncommon and more often than not is non-IHS Apache HTTP Server documentation being mis-applied to IHS.

Unsupported mod_proxy configurations

• The generic proxy support in mod_proxy is never supported as a frontend to WebSphere Application Server. The WebSphere Plugin is the only supported mechanism to connect IHS with WebSphere Application Server (tWAS and Liberty).

  If you need mod_proxy, use non-IHS Apache HTTP Server.

• The reverse proxy is frontending a non-IBM Application Server (including non-java Application Servers).

mod_proxy as "other configuration"

These configurations are not designed, tested, or recommended as part of any IBM product that bundles IBM HTTP Server (such as WebSphere). Customer and Product support is limited to issues that are in common with a supported configuration. See https://www.ibm.com/support/pages/node/317639 for details of "other configuration"

Note: Comments below are applicable only to mod_proxy, not the WebSphere Plug-in!

• Using IHS as a reverse proxy in front of another IHS that meets the support requirements. This is not a recommended or tested topology.

• Using IHS to provide outbound connectivity, either as a forward or reverse proxy for applications running inside of WAS. In the case that this outbound destination is IBM Bluemix, see the IBM Secure Gateway product.

  • If the remote service is running on WAS, it can of course be fronted by IHS w/ the WAS WebServer Plug-in.

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.

• WebSphere Datapower, ISAM (WebSeal), and API Connect are all IBM products that provide reverse proxy functionality.

• IBM Secure Gateway provides TCP and SSL gateway services into and out of IBM Bluemix.

• Dedicated open-source solutions, such as haproxy, nginx or squid, are often ideal when colocation with a webserver isn't a requirement.

• Vanilla Apache HTTP Server from an enterprise linux vendor is likely to have more timely proxy-related function and fixes.

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.