mod_wcm.so

Mod WCM Setup

The mod_wcm.so is an Apache module that provides a proxy like interface for KCML SOAP, KCML HTTP and KCML JClient applications. For KCML SOAP and KCML HTTP applications the module routes incoming requests to any free KCML instance in the correct pool of KCML instances. A separate pool is maintained for each application type. If no KCML instance is available to the module it will try to spawn a new one. The ability to spawn new instances is usually constrained by licence.

The configuration of Apache modules varies on different platform, see the links for platform-specific examples.

Apache2.4

It is recommended to upgrade to Apache 2.4 as Apache 2.2 is now considered legacy with support expected to stop in 2017 (see Apache). Versions of mod_wcm for Apache 2.4 are discussed in the operating-specific sections below, see Apache Configuration.

KCML SOAP application

To run a KCML application as a SOAP service you need special configuration in the Connection Manager. An example service:

kconf.xml:

<kconf>
...
	<services>
	...
		<service>
			<name>K8_CVS6</name>
			...
			<soap>
				<soapservice>
					<url>KCMLTest</url>
					<start>soapserver.src</start>
				</soapservice>
			</soap>
		</service>
	...
	</services>
...
</kconf>

The definition for this KCML SOAP service would be reachable from 'http://hostname:790/K8_CVS6/KCMLTest?WSDL'. Running a production KCML SOAP service via the connection manager alone is strongly discouraged. The architecture of the connection manager would lead to high latency for each request. To overcome this we use the Apache.

The location configured in Apache must match the service/soapservice configured in the connection manager. An example Apache config:

httpd.conf:

<Location /K8_CVS6 >
	Order allow,deny
	Allow from all
	# mod_filter and mod_deflate must be loaded
	AddOutputFilterByType deflate text/plain text/html text/css text/xml application/soap+xml
</Location>
<Location /K8_CVS6/KCMLTest>
	SetHandler kcml-soap
	KcmlSOAPServers localhost:790
</Location>

'SetHandler kcml-soap' - instructs the module that this location is used for SOAP calls.
'KcmlSOAPServers localhost:790' - instructs the module where to find the connection manager that will be used to spawn KCML SOAP instances.

KCML HTTP application

To run a KCML application as a HTTP application you need special configuration in the Connection Manager. An example service:

kconf.xml:

<kconf>
...
	<services>
	...
		<service>
			<name>K8_CVS6</name>
			...
			<soap>
				<soapservice>
					<url>KCMLTest</url>
					<start>soapserver.src</start>
				</soapservice>
			</soap>
		</service>
	...
	</services>
...
</kconf>

Although this is a KCML HTTP application it lazily reuses the soap/soapservice configuration from the KCML SOAP example. This is because as far as the Connection manager is concerned there is no difference between the two.

All HTTP requests to 'http://localhost:790/K8_CVS6/KCMLTest' and beyond would be passed to the KCML HTTP application.

The configuration for Apache does differ from the SOAP example. This is because the module has some built in SOAP processing that is not needed for HTTP applications. An example:

<Location /K8_CVS6/K8_CVS6/KCMLTest>
	Order allow,deny
	Allow from all
	# mod_filter and mod_deflate must be loaded
	AddOutputFilterByType deflate text/plain text/html text/css text/xml application/soap+xml
	SetHandler kcml-http
	KcmlAppServers localhost:790
</Location>

Note: SetHandler is now set to kcml-http.

Note: we now use KcmlAppServers instead of KcmlSOAPServers.

KCML JClient

The module provides session management for the browser based JClient.

Apache Configuration

A quick reference guide to mod_wcm.so Apache directives can be found here

For the sensitive directive KcmlAuthSecret it is recommended you use include files for your configuration that can have permissions strictly controlled.

Apache 2.2 & 2.4 are available on most operating systems, however they have different configuration layouts

See: Operating System versions to identify the Linux distribution that is being used.

An Apache 2.4 version of mod_wcm.so is also available for 64-bit Linux operating systems.
Unix versions of mod_wcm.so are only compatible with the prefork-mpm version of Apache.
See:- System Requirements

Documentation on common Apache configuration directives is available here and here.

MaxClients - Controls the total concurrent connections to Apache. This number should represent the highest possible number of users for your service.
KeepAlive - This should be On so the connection isn't dropped after each request.

A guide to tuning Apache for performance can be found here.

Other Apache Modules

It is recommended you use these existing Apache modules:

mod_deflate. This provides compression of HTTP responses. Saves bandwidth at the cost of CPU time.
mod_cache. This provides content caching.

Notes

xinetd

The default configuration for Connection Manager started via xinetd will limit the Connections Per Second to 50. This has sometimes proved to be to small on high usage servers. It is suggested that you set CPS to a higher value. Please refer to your xinetd documentation.