james-server-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Paul Hammant <Paul_Hamm...@yahoo.com>
Subject Re: Tomcat + James in a single jvm process
Date Tue, 04 Jun 2002 22:29:08 GMT

We're trying to make Phoenix an industrial strength app.  Think 
WebLogic.  Love it or hate it, it is big.
We'd certainly suggest that an 'assembler' could choose one or two VMs 
for such a configuration.

- Paul

>While it is true that starting and running a single JVM instance is less
>expensive (mostly in terms of memory)
>than starting and running two or more JVMs on the same processor/box,
>there are several good reasons for
>keeping Tomcat and James running in separate JVMs. Trying to avoid the
>"overhead" of two JVMs really
>doesn't gain you anything significant. What is more critical is the work
>done inside the two threads (James,Tomcat).
>Heap size is a concern. JVMs have a limit on the amount of memory they use
>by default. You can run the JVM with a -server
>option, which AFAIK increases that limit. However, depending on your load,
>having both Tomcat and James in the same JVM may cause you to run
>into a shortage of resources within the JVM, even though you may have
>saved on memory outside the JVM.
>Second, you are putting all your eggs in one basket (sorry for the idiom).
>Putting both Tomcat and James in the same JVM
>is not a fault-tolerant solution. If the JVM crashes, you lose both your
>servers. If your clients have a two processor machine,
>or two boxes, keeping them separate will provide you and them with a more
>scaleable solution.
>Third, it should be relatively simple for you to write a custom
>start/build script that runs both Tomcat and James. In this way, it
>still "looks" like you are starting a single process, but inside the
>script you start 2 JVMs (or call the Tomcat startup script and the James
>startup script). That approach is much easier than trying to tie the two
>binaries together or compile a custom version.
>If you are looking for tutorials for Tomcat, the documentation within the
>Tomcat distributions and on the tomcat website is
>very good. http://jakarta.apache.org/tomcat/  The default configuration
>for the Tomcat distribution runs with minimal changes.
>Of course, what JSP/webapps you put in from there is another story ;) The
>tomcat-users mailing list should be fairly helpful along with the docs.
>I hope this has been helpful.
>----- Original Message -----
>From: "mohan narayanaswamy" <mohandb2@yahoo.co.uk>
>To: "James Developers List" <james-dev@jakarta.apache.org>
>Sent: Tuesday, June 04, 2002 7:02 AM
>Subject: RE: Tomcat + James in a single jvm process
>>single JVM process will reduce the overload.
>>u will be required less cpu,memory and moreover
>>efficient when compared to two process server.
>To unsubscribe, e-mail:   <mailto:james-dev-unsubscribe@jakarta.apache.org>
>For additional commands, e-mail: <mailto:james-dev-help@jakarta.apache.org>

To unsubscribe, e-mail:   <mailto:james-dev-unsubscribe@jakarta.apache.org>
For additional commands, e-mail: <mailto:james-dev-help@jakarta.apache.org>

View raw message