GJS: KB0132

What Configuration Settings Affect the Performance of the Browser Interface?

Applies to: VC/m 2.4 onwards

When using the VC/m browser interface, there are two settings in Internet Explorer and IIS which can have a significant effect on the number of round-trip requests between the client and the server.

On a slow or loaded network or when accessing VC/m over a WAN or Internet connection, the number of round-trips can have a significant impact on the performance of the user interface.

Impact Analysis

This table summarizes the number of round-trip request /responses which were generated for a VC/m session with different settings:

Test	IIS Content Expiration	IE Check for Newer Versions	Number of Requests
1	Enabled	Automatically	82
2	Enabled	Every Visit	100
3	Disabled	Automatically	108
4	Disabled	Every Visit	1610

As can be seen, if page caching is disabled both within IE and on the web-server, performance can be particularly bad.

Recommended Settings

For best results you should enable content expiration on the web-server (the default setting of 1 day is more than adequate), and have your browser set to automatically check for new versions of the page (this is IE's default setting).

Updating VC/m

Following a VC/m update, if your browser clients previously requested the resource within the expiration period, they will not fetch updated files from the web-server. Some ways of dealing with this are:

Disable content expiration sufficiently far in advance of the update to guarantee that all browsers will request new copies of files.
Reduce content expiration. On IIS the minimum value is 1 minute.
Tell browser users to empty their local cache before using the updated VC/m server.

Last reviewed: Sept 28, 2004