WebSphere vs Tomcat, when to use...

Hello Anders,
may be it won't answer all your questions, but a good reading might be:
IBM Rational Team Concert Version 1.0 Server Sizing Guide

http://www.ibm.com/developerworks/rational/downloads/08/rtc_v1serverguide/

Eric.

anders.m a crit :

Hi,
Is there any documentation about when to use WebSphere instead of
Tomcat?
On the database side, Derby is default and shipped, but there is a
limitation on 10 users.
On the application server side, I can not find any information. When
should you go for WebSphere and why?

Best Regards
Anders

If Tomcat works for you I would suggest staying with Tomcat because it
is simple to use and takes almost no configuration.

Some people prefer WAS because they are already comfortable with it, or
they already have a WAS server hosting other applications. Another
reason would be to leverage support for federated user registries (to
combine local and LDAP user registries).

-
Matt Lavin
Jazz Server Team


On Wed, 2009-02-04 at 08:28 +0000, anders.m wrote:

Hi,
Is there any documentation about when to use WebSphere instead of
Tomcat?
On the database side, Derby is default and shipped, but there is a
limitation on 10 users.
On the application server side, I can not find any information. When
should you go for WebSphere and why?

Best Regards
Anders

One reason to use WAS is if you want to use a standalone feed reader. These require basic auth. Technically basic auth requires an authentication with every request - this means that if you are using LDAP you may hit LDAP hard depending on the # of users you have. WebSphere has some smarts in it that caches the basic authentication success and avoids pounding the LDAP server. Tomcat does not have this.

My group migrated our multitude of CLM applications from Tomcat to WebSphere this past August.  The major reason is that our applications have a V2 heritage and because of access controls to project areas coming along later, we ended up with 20 distributed RTC applications all in Tomcat.  Along the way, we started deploying QM and the applications became more and more friendly and with the Tomcat application server at the fore, users grumbled at the multiple logins required.   Now with WebSphere a user can login to an application and easily switch to another w/o the need for a second login.

Another reason is that if one needs to update Tomcat or Java in this mileau, one must update as many Tomcat/Java as one has deployed.  While that is relatively simple, it is a pain-point as an application administrator.  Since we have chosen to host several applications on a few AIX LPAR,  WebSphere profiles were created for each application on a given partition.  In this way, updating WAS only needs to happen once and all the existing profiles benefit.