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From Stefano Bagnara <apa...@bago.org>
Subject Re: IMAP Draft: Cluster
Date Fri, 14 Jul 2006 14:37:04 GMT
Joachim Draeger wrote:
>> IMAP is a perfect case for SEDA because often there are a lot of idle 
>> collection and without SEDA you need to keep idle threads allocated.
> How much does it cost to keep an idle thread allocated? Is it only using
> memory or using a lot of memory or does the JVM need cpu time to deal
> with them?

IIRC each jvm thread needs 512K memory for the stack inside the JVM: 
some application, like resin, bump this value to 2MB at startup (to 
avoid OOM under deep calls, I guess). (-Xss is the jvm parameter to tune it)

Furthermore each JVM implements threads differently on various OSes. 
Again IIRC jvm 1.4 under linux uses linux processes for threads and this 
means more memory and resouces for the machine (default stack for a 
linux process should be 4-32K)

I don't know enought the JVM threading model to say how much does the 
number of threads impact on the performances.

> Do you recommend using SEDA instead of MINA?

At a glance MINA "is" SEDA for JAVA.


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