[rabbitmq-discuss] Problem with RabbitMQ Java Client (Memory leak)

[Steve Powell]

Yogesh,

Thank you for this problem report. First point: each connection defines a
(hidden) channel zero, so that explains why there are 20001 of some objects and
20000 of others.

As to why these are not garbage collected, we must be holding a reference
somewhere (probably in the Connection).

We will investigate. I have raised a bug (24723).

Steve Powell  (a happy bunny)
----------some more definitions from the SPD----------
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On 31 Jan 2012, at 17:49, Yogesh Ketkar wrote:

> I am using rabbitmq-java-client-bin-2.7.1/rabbitmq-client.jar with
> RabbitMQ 2.7.1 Server.
> 
> Just run this code
> 
> public static void main(String[] argv) throws IOException {
>    ConnectionFactory f = new ConnectionFactory();
>    Connection c = f.newConnection();
>    for(int i = 0; i < 20000; ++i) {
>        Channel ch = c.createChannel();
>        ch.close();
>    }
>    System.gc();
>    while(true) {}
> }
> 
> While program is running, observe the memory usage, it keeps on
> increasing
> Get process id and do following
> jmap -dump:format=b,file=yo.bin  <pid>
> jhat jhat -J-mx768m -stack false yo.bin
> Once jhat brings up http server, go here
> http://localhost:7000/showInstanceCounts/
> 
> 20001 instances of class com.rabbitmq.client.impl.AMQCommand
> 20001 instances of class com.rabbitmq.client.impl.CommandAssembler
> 20000 instances of class com.rabbitmq.client.ShutdownSignalException
> 20000 instances of class com.rabbitmq.client.impl.AMQImpl$Channel
> $Close
> 20000 instances of class com.rabbitmq.client.impl.ChannelN
> 20000 instances of class com.rabbitmq.client.impl.ConsumerDispatcher
> 
> In-spite of closing all the channels, not only channels but associated
> objects (ShutdownSignalException, ChannelClose) continue to consume
> memory.
> For sure, knowing this now, I will use channelCreate call sparingly.
> 
> Is there a way to remedy this situation?
> What is also worrying is instances of AMQCommand, so would this be the
> case for each and every call of client library?
> 
> regards, Yogesh
> 
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