There are a few lightly documented
options to hotspot that may
improve gc behaiour for you.
(from memory try
-Xincgc -Xminf.30 -Xmaxf.70
)
searching for -Xincgc on the
java developer site should
turn up some documentation.
=?iso-8859-1?Q?Frank_Karlstr=F8m?= <[EMAIL PROTECTED]> wrote:
__________
>We also have this problem with our server.
>
>After a bit of memory debugging, it seems that our servlets and all depended
>classes are almost gc'ed. But there always remains a 20 byte reference to
>the servlet and all depended classes. So if your servlet is somewhat
>complicated, this will eat your memory by 4K for every hit to your servlet.
>when the memory consumption reashes the heap roof, Garbagecollection takes
>place, and the heap is enlarged.And so it continues from the beginning until
>it runs of of heap space again.
>Again and again, until the heap can grow no more, and the jwm stops
>responding, often taking the OS down too.
>
>
>The only solution so far for this problem has been twofolded:
>1. take a restart every day.
>or
>2. have a thread running in the background doing a manual GC every now and
>then.
>
>None of these solutions are good ones. So if someone can point out to as
>what we are doing wrong, or show us a workaround, lives will definentily be
>much easiyer.
>
>(PS. we are using SilverStream Application Server v. 3.7,
>Java JRE 1.3.0 with HotSpot VM 1.3.0-C, mixed mode)
>
>
>
>
>----- Original Message -----
>From: "A R Krishna" <[EMAIL PROTECTED]>
>To: <[EMAIL PROTECTED]>
>Sent: Thursday, June 28, 2001 8:44 AM
>Subject: JWS Crashing with Extra memory usage by JREW - heap memory problem.
>
>
>> We have observed the following problem on our server. We are running
>> Java Web Server 2.0 on WinNT4.0 machine with Dual 933MHZ
>> PIII, 1GB Ram Dell Server.
>>
>> The memory leaks happen every time, but the method of crash always seems
>to
>> vary. Sometimes the service just stops responding. The only way to bring
>> it back is to kill the jrew.exe process, stop the service, and start the
>> service. This works about 70% of the time.
>>
>> Sometimes after restarting the service, JWS still doesn't respond until
>> we go into the admin tool and change the web page service from stopped to
>> started. This happens about 15% of the time. Sometimes jrew GPF's.
>> I often have to reboot after this happens, but sometimes I can just stop
>> and start the service and it comes back up. This happens about 10% of the
>> time. The final 5% of the crashes are the most spectacular. This is
>where
>> the whole system stops responding, even to mouse movement. A hard reboot
>is the only solution here. But every time JWS crashes, there is never
>anything in the logs to give any clue as to what happened.
>>
>> We have also observed that the memory gets allocated to jrew.exe in chunks
>ranging from 4K to 16K until it tops out at the maximum VM setting and
>throws exceptions. Surprising thing is that even while serving the html
>pages the above said chunk of memory is getting assigned to the jrew.exe.
>This process continues till the memory used by jrew.exe reaches allocated
>cache memory and then the problem reported in para 2 above starts.
>>
>> we have allocated 750MB for Heap Memory and 384MB for cache memory.
>>
>> I have even tried out using System.gc() in all the servlets but there is
>no improvement at all.
>>
>> Anyone have any ideas ? Thanks,
>>
>> RK
>>
>>
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