Applying Http proxy in the information network of University Veszprem

Pulai Gábor <pulaig@almos.vein.hu>

Veszprémi Egyetem

Farkas Zoltán <farkas@almos.vein.hu>

Veszprémi Egyetem

1. What is a Proxy server?

The meaning of the word proxy is agent. Corresponding to this we use proxy servers to accomplish jobs, which could not be made or could not be allowed to make by different machines.

• What is a proxy server used for?

  • To accelerate web access

  • To accelerate web service

  • As Firewall

  • Etc

• What are we using proxy server for?

Today at the University we use it to accelerate web access. Earlier we used it to save WAN bandwidth.

2. What sort of Cache servers available on the market?

• Harvest

• Squid

• NetCache

• Microsoft Proxy Server / Internet Security and Acceleration Server

3. What we are using? Why?

Between 1997 – 2000: We used Harvest, than Squid cache on Solaris and Linux platform.

Since March 1, 2001: The GE Capital ITS Austria via VAR Ltd gave and configured a Network Appliance’s NetCache 720s proxy serve to the University Veszprem as a gift.

4. Experiences of introduction of the Cache System

• In general:

Introducing new systems – especially when it is a ‘must’ use – always problematic.

One possible solution is: the transparent proxy. It is slower and generates more network traffic. That is why we did not use it.

• In case of NetCache:

It happened nearly seamless. Because we were keeping in mind, that our users should not have make any changes in their local configuration setting. And we had fighted the introduction problems with former cache solutions already.

5. Experiences of usage

• The NetCache operates in a very stable method. Nearly no maintenance required comparing to Squid. With Squid we had to make troubleshooting once in a week or once in a two-week period. The latest Squid versions (stable) still have problems in using the file system. It stops the system (and can be set to automatically restart it). The stops generate a lot of ‘stucked in’ objects, which cannot be accessed or deleted. And the only possible solution to eliminate them is the regeneration of the cache’s directory structure. These objects in worst case can occupy up to 60% of disk space.

• Statistically: the daily hit rate is 45% at 27 GB Cache size, at 1210 request/min. The Squid had 28% – 37% hit rate.

• The average response time increased 35%, and the negative hit’s response time increased nearly 50%.

6. Summary

• The NetCache 720s is suitable for the load of University Veszprem

• The users get better response times using the new proxy server

• Nearly no maintenance required

• NetCache operates in chain (cascade) with other proxy servers (Squid, ISA)

• We can repurpose the former high capacity hardware