HP WebQoS Peak for HP-UX Concepts and Operation Guide

58 Chapter5

HP WebQoS Peak for the Apache Web Server

Integrating HP WebQoS with the Apache Web Server

directive. For example, assuming that mime caching is on, the following

directive turns off caching for the speciﬁed mime types:

HPACMimeNocache video/x-mpeg2 audio/x-pn-realaudio

You can add to the default list of mime types that can be cached with the

HPACMimeCache directive. For example, if mime caching is on, the

following directive adds the speciﬁed mime types to the list of mime

types that can be cached:

HPACMimeCache image/x-rgb image/x-xpixmap

NOTE If the list of mime types passed to the HPACMimeNocache and

HPACMimeCache directives is too long to ﬁt on one line, the newline

character must be escaped on all but the last line.

The caching commands speciﬁed in the conﬁguration ﬁle have no effect if

a document cannot be cached in the ﬁrst place (for instance, documents

created dynamically).

System Resources Sharing Among Virtual Hosts By default, each

virtual host equally shares the system resources. However, this does not

guarantee equal use of the resources. Virtual hosts hosting active sites

may use more than their fair share of system resources, at the expense of

other virtual hosts. A more equitable use of system resources can be

achieved using one of the techniques described below.

You can inﬂuence the access of virtual servers to system resources by

using different load thresholds for the virtual hosts. For instance, you

could set the load threshold lower for virtual hosts that have a tendency

to use most of the system resources. Conversely, you can set the load

threshold higher, or even turn off HP WebQoS, for virtual hosts that have

little impact on the system resources.

You can use the HPACShareUnits directive to give more weight to some of

the virtual hosts. The default for this directive is “1.” For example, to give

more weight to some of the virtual hosts, use the following directive in

your conﬁguration ﬁle:

HPACShareUnits 2

To understand the effect of this command, assume that you have three

virtual hosts, A, B and C: A is assigned one share of system resources, B

is assigned two shares and C is assigned three shares. (There are a total