JServ vs. Tomcat

[Tim Wright <ti...@uk.another.com>]

Hi,

I work for an free web based mail service, Another.com. We are interested in
migrating our service to use either JServ or Tomcat. We currently has a
server farm with 10 web servers running Apache and a JRun on each machine.
We are interested in changing the architecture to use a small number of
Apache web servers (e.g. 2) with a set of load balanced Tomcat or JServ
boxes.

My understanding is that this arhitecture could be achieved with either
Tomcat or JServ. Tomcat is perferable from a developers perspective, but is
Tomcat considered subitble for a production environment?

I was particulatly worried by the problem of Apache hanging when Tomcat is
restarted. Since we release new build of the site regularly, we need a
mechanism to rollout new builds onto servers. Concider the following
example:

We have 2 appache servers (WEB1, WEB2) connecting to 6 Tomcat server (TC1 -
TC2).

Initial all the tomcat servers TC1 - TC3 are running build 1.0. TC4 - TC6
are out of use.

We want to release build 1.1 onto TC4 - TC6. We then need to configure the
web boxes to send all new sessions to TC4 - TC6, whilst maintaining old
session on TC1 - TC3. Can this be done without restarting the WEB1 and WEB2.

At some later date we need to restart TC1 - TC3 with build 1.2, whilst
maintain sessions on TC4 - TC6. If we restart TC1 - TC3, will this cause
WEB1 and WEB2 to lock?

I would appreciate any advice or comments.


Cheers
Tim Wright
Java Engineer
Another.com