direct buffer memory issues

[Adam Fisk]

I think I got it Trustin -- I wasn't calling releaseExternalResources
in all cases. It's a little tricky to handle that in the proxy
scenario where the clients themselves have "handlers" in the pipeline.
It looks like *I should not call it* in channelClosed event handlers,
is that correct? Do so generated CPU spikes for me.

All looking good now, though -- total OS memory hovering around 65 MB
with opening lots of connections.

Thanks.

-Adam

On Sun, Mar 7, 2010 at 8:20 PM, "Trustin Lee (이희승)" <trustin at gmail.com> wrote:
> Hi Adam,
>
> Thanks for reporting the problem.
>
> Could you send me the heap dump?  I need it to determine if it's a JDK
> issue or Netty SocketSendBufferPool issue.
>
> I also would like to know if you are getting many ClosedChannelException
> or NotYetConnectedException.  If that's the case, try this build: (wait
> for a while if you get 404)
>
>    http://hudson.jboss.org/hudson/view/Netty/job/netty/3416/
>
> Decreasing the preallocation size will not fix the problem because
> preallocation is already shared by many write requests for different
> connections to maximize its utilization.
>
> HTH,
> Trustin
>
> Adam Fisk wrote:
>> I'm experiencing an issue where LittleProxy eventually runs out of
>> memory, but in direct memory allocated through allocateDirect, not in
>> the object heap. Here's a link to the issue with the stack trace:
>>
>> http://dev.littleshoot.org:8081/browse/LP-16
>>
>> I tried using -XX:MaxDirectMemorySize=256M, but that just seems to
>> delay the issue. If I look at the actual OS-level memory allocated,
>> once it gets up to around 300MB, I can't allocate more (basically the
>> 256 + 40MB or so for the object heap and whatever else).
>>
>> It fails in SocketSendBufferPool when creating the "Preallocation"
>> with DEFAULT_PREALLOCATION_SIZE = 65536. In LittleProxy's case, that's
>> when we're allocating new HTTP clients to go out to servers to fetch
>> data. Many of those connections don't end up passing much data
>> upstream (although some POST requests clearly will). Any way to set
>> that buffer size on a per-client basis?
>>
>> I'm not exactly sure what to do other than boosting
>> XX:MaxDirectMemorySize even further.
>>
>> The other odd thing is the memory *never seems to go down*, even after
>> all the threads are done. Is it possible I'm not cleaning up those
>> client connections properly? It seems like any buffer allocated with
>> allocateDirect never gets freed.
>>
>> Any suggestions you may have would be much appreciated.
>>
>> Outside of this issue, things are looking great!!
>>
>> Thanks Trustin.
>>
>> -Adam
>>
>
> --
> what we call human nature in actuality is human habit
> http://gleamynode.net/
>
>
>
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-- 
Adam Fisk
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