Gordon Welling
Admin Group
Manager Technnical Support Services
Joined: 11-December-2003
Location: Canada
Posts: 555
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| Posted: 06-November-2006 at 1:19pm
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Multiplied SLED 10 Internet Performance Tip
Read this tip about how to improve Internet Access performance when deploying the Multiplied SLED 10
Strategy. In addition to saving 80-90% on their desktop
deployment and maintenance compared to stand-alone Microsoft desktop
deployments, this article explains how to enhance the user Internet
experience.
It is a generally accepted best practice to
enhance Internet browsing speed by configuring browsers on individual
workstations to query a local proxy server for web content. It is
well understood that by allowing the client to cache content in the
local workstation hard drive, performance is increased and the user
browsing experience is enhanced. That's all fine and well for
stand-alone deployments. But how might this be different for a
Multiplied SLED 10 deployment?
With an installation of Desktop Multiplier
on SLED 10, there can be up to 10 users using the same hardware to surf
the internet. Depending on the hard disk channel, allowing each
of those users to cache many small files to the "local" hard drive
(which is actually a shared hard drive with a Multiplied deployment),
can cause a potential hard disk read/write performance bottleneck.
So,
how do you get around this possible bottleneck? Well, not only do we
"get around the bottleneck", we go one step further - we significantly
enhance internet browsing on a Multiplied SLED system.
The
default user profile for FireFox (the default browser for SLED) uses an
individual session browser cache. Each time the user visits a
site, the browser automatically reads and writes many very small files
to the "local" cache and uses those files for faster access if they
have not been changed since the last visit to the site. By
default, this process works the same way on a Multiplied SLED
system. With a Multiplie SLED system, information for user
sessions, including files, are not shared - but the hard drive is
shared. This increases the number of read and write operations to
the single hard drive by 10! 10 times the hard disk activity -
how can we remove the bottleneck in the above scenario?
The
answer is simple ... implement a local proxy cache on the host PC
running the Desktop Multiplier. Well, actually, it is a bit more
complicated than that. Here's how it works:
- Login as 'root' and install and configure the squid proxy server;
- Configure the proxy server as a transparent proxy;
- Start the squid proxy server;
- Configure each user's FireFox options to:
- set the proxy cache to 0 MB,
- delete all existing proxy cache files, and
- configure
the browser connection settings (Tools > Options ... > General
> Connection Settings) to "Auto-detect proxy settings for this
network" or to set the manual proxy access and specify the appropriate
IP address and port value. Because they are all configured to the
same workstation, the default of 127.0.0.1 port 8080 could be used.
What is the impact of these changes?
When a user surfs the Internet using FireFox, the browser will still
check for a proxy, but instead of checking its own file cache, the
browser checks the "shared" squid proxy database cache. This
significantly increases the number of cached files that will be found
in the host workstation memory, and increases internet access because
the users will not all be caching individual copies of the files on the
hard disk. In addition, because Squid caches files in an indexed
database, the read / write access is enhanced, CPU and disk access are
decreased and the number of read/write operations is significantly
decreased. Instead of 10 independent concurrent sets of many
small file read - write requests, the Squid proxy service uses its
shared database process to increase performance.
In many
environments, many Multipled SLED systems are on the same LAN.
This would be the case in computer lab, corporate environments or with
public access computers. By configuring the Squid proxy cache
servers running on each Multiplied system to act as a as peer-to-peer
caches for the other systems, you can significantly increase
performance. Web sites are serviced at LAN speed rather than over
your WAN connection to a centrally configured proxy server.
Another option is to configure the Multiplied system Squid proxy
servers as child proxies in a hierarchy cache configuration.
Click here
for more information about how the Desktop Multiplier for SLED strategy
can save 80-90% when compared to Microsoft stand-alone computers:
www.omni-ts.com/linux-desktop/
For more information on installing and configuring the squid proxy server provided with SLED 10 or openSUSE 10.x, see:
Edited by Aldo Zanoni on 06-November-2006 at 1:55pm
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Omni Web Forum : Linux Desktop Multiplier : Linux Desktop Multiplier for SLED and openSUSE
Topic: TIP: Improve Internet Access Performance
