tomcat-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Wade Chandler <wchand...@redesetgrow.com>
Subject Re: Tomcat/Java and SMP
Date Fri, 03 Dec 2004 20:05:30 GMT
Dan Foreman wrote:
> Yes, 10 separate boxes with a single JVM (tomcat instance) running on each box.  All
boxes are SMP.
> 
> -----Original Message-----
> From: David Boyer [mailto:David@bvu.edu] 
> Sent: Friday, December 03, 2004 12:32 PM
> To: tomcat-user@jakarta.apache.org
> Subject: RE: Tomcat/Java and SMP
> 
> So these are 10 separate boxes?
>  
> I think the clarification is necessary because "application server" in the context of
java usually refers to the J2EE or (sometimes)
> servlet container. Are you taling about 10 instances of tomcat each running on their
own box?
> 
> 
>>>>Dan.Foreman@epillar.net 12/3/2004 11:20:55 AM >>>
> 
> 
> 10 application servers. 
> 
> -----Original Message-----
> From: Kwok Peng Tuck [mailto:pengtuck@gmail.com]
> Sent: Friday, December 03, 2004 6:53 AM
> To: Tomcat Users List
> Subject: Re: Tomcat/Java and SMP
> 
> Dan,
>     U have 10 application servers on one machine or 10 application on 10 distinct machines
?
> 
> Dan Foreman wrote:
> 
>>Hi,
>>
>>I have a setup of 10 application servers using Tomcat 4/5, jsdk 
>>1.4.2_02, SMP, win2k.  In watching the performance under load I am 
>>concerned that only one CPU is being utilized at a time.  To validate
> 
> 
>>my theory I try hitting the application server with a request to 
>>generate a large report and then making another connection.  The 
>>second connection is painfully slow and task manager only reports a 
>>50% CPU utilization.  After doing some reading on SMP/native threads
> 
> 
>>and windows, I wrote a test java application that spawns n infinite 
>>loop threads from a single JVM with a delay between each creation.
>>Sure enough one cpu (task manager reporting
>>50%) and then the other cpu are consumed (task manager reporting 
>>100%).  This test tells me that Java is capable of using both CPU's
> 
> via native threading and some black magic in the windows dll's but that this scenario
isn't happening in tomcat.
> 
>>Is it possible for tomcat to use more than one CPU or is there a
> 
> critical flaw in my logic?
> 
>>-Dan
>>
>>
>>
> 
> ---------------------------------------------------------------------
> 
>>To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
>>For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
>>
>>
> 
> 
> 
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> 
> 
> 
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> 
> 
> 
> 
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: tomcat-user-help@jakarta.apache.org
> 
> 
> 

Hmm.  I would write a small test to hit my http url to cause tomcat to 
fire up more threads just to get a feel for it.  Also maybe make a JSP 
page and call Runtime.getRuntime().availableProcessors() and print that 
to the screen and see how many processors the JVM thinks it has 
available.  You might want to loop for something like 30seconds reading 
this number every few milliseconds in your jsp page and print out all 
unique values.  You could then hit tomcat server multiple times by some 
client your write.  Write a simple java app that spawns off multiple 
threads and have each thread record it's own findings from the jsp page. 
  This could give you some insight as to whether it is working right or 
not.  I would make the jsp page for a starter and let it run 30 seconds 
and record unique values and see what I end up with.  Maybe then you can 
change it up to see how many times the value changes if you find you get 
weird results.

Wade


---------------------------------------------------------------------
To unsubscribe, e-mail: tomcat-user-unsubscribe@jakarta.apache.org
For additional commands, e-mail: tomcat-user-help@jakarta.apache.org


Mime
View raw message