tomcat-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Roy Wilson <>
Subject Tomcat 4.0 Milestone 4 and performance issues
Date Wed, 01 Nov 2000 01:24:21 GMT

Has anyone used ab to stress test any versions of Tomcat when used as an 
in-process servlet container (Costin, Craig, Pier)? (I am a newbie at 
both Apache and Tomcat: I assume that using Tomcat and Apache together 
implies that Tomcat is used in an in-process mode.) If so, do you 
anticipate any procedural changes needed to do the same with Tomcat-4.0? 
I ask because I'd like to do some measurements of thruput and resource 
demand once the connector is available and am wondering whether I'll need 
to do more than install Tomcat, get it running, and fire up ab. I know 
the definitive answer that won't be known until the connector is up and 
Per an early suggestion from Costin or Craig, I've been doing some 
simplistic static HTML page ApacheBench based measurements (of Apache 
only) in localhost mode (yeah, I know ...) representing an Intranet usage 
scenario. In short, I use ab to drive Apache while running sar and sa in 
the background. From sar and sa, I derive per request CPU and disk 
service time estimates for ab and httpd. These values are used as inputs 
to a (too simple) queueing model. The model generates average queue 
lengths, resource utilizations and average system response time for large 
populations of users. For the intranet case, it also allows me to look at 
the impact of a non-zero think time: ab assumes (in effect) a population 
of C continuously active users. The model also makes possible a SWAG 
(scientific wild-ass-guess) about performance and capacity across 
processors (using CPUmark99 or some such numbers) and processor 
configurations. This is rude and crude, I admit, but sometimes good for 
comparing systems. And the model runs in a matter of seconds, so 
sensitivity analysis is almost free. 

If there's any interest, I can post a link to a PowerPoint presentation 
that summarizes what I've done so far (and let the barbecue begin :-)).

Roy Wilson

>>>>>>>>>>>>>>>>>> Original Message

On 10/31/00, 7:09:41 PM, "Craig R. McClanahan" 
<> wrote regarding Tomcat 4.0 Milestone 4:

> Hey folks,

> I'm planning on cutting a fourth milestone of Tomcat 4.0 tomorrow
> (Wednesday) evening.  This milestone will reflect all of the changes
> that occurred in the servlet 2.3 and JSP 1.2 specifications between
> public draft and proposed final draft (and there were a *bunch* of
> them), completion of the remaining new 2.3/1.2 functionality, and
> several bug fixes.

> This will be the last big push of spec-related functionality additions
> for Tomcat 4.0.  Now, we can turn our attention more towards bug fixes
> and performance tuning.  You can help in that process by downloading and
> playing with the Tomcat 4.0 milestone.  I'd like to see us shake it out
> enough to be production quality by Christmas time.

> Besides bug fixing and tuning, I know of several pieces of functionality
> yet to be added that are being worked on, including:

> * Web connectors (using a new connector protocol
>   called mod_warp that is aware of webapp configuration
>   settings, so you will not have to configure things twice).

> * JNDI context support (like that used in J2EE servers)
>   for the <env-entry> and <resource-ref> configuration
>   parameters in the deployment descriptor.

> If you are interested in contributing to Tomcat 4.0, there is a "wish
> list" document in file "catalina/STATUS.html" in the jakarta-tomcat-4.0
> source tree.  Feel free to propose new ideas, or to volunteer to work on
> one of these.

> Craig McClanahan

> ---------------------------------------------------------------------
> To unsubscribe, e-mail:
> For additional commands, e-mail:

View raw message