Hans, I'm using JMS for Axis 2 with WebSphere MQ 6.0.2 in production and
found some severe limitations with the Axis 2 implementation also -
whoever wrote the actual Axis 2 driver has only implemented the bare
basics of JMS, and it hasn't been tested with WebSphere at all.
I'm using it over publish subscribe and had to switch the transport to
perform explicit message acknowledgement so that it didn't lose messages
and so that it would work with durable subscriptions. I also added
durable subscription support so that if Axis 2 is down, it gets all the
missed messages when it reconnects. Additionally the JMS Sender
transport class has memory leaks where it creates a new JNDI context
with every message sent and then never cleans it up, causing the actual
MQ server to eventually fall over or stop accepting connections (meaning
a server reboot).
Also a major issue is that Axis 2 does not handle JMS errors, such as
the MQ server or network connections being unavailable. If this happens
at all, you need to restart your Axis 2 once the MQ becomes visible again.
I've fixed up a lot of these problems myself, except for the last one.
If you're interested, check them out at:
http://thejavamonkey.blogspot.com/2008/08/modding-axis-2-durable-subscriptions.html
http://thejavamonkey.blogspot.com/2008/08/modding-axis-2-jms-transportweb-sphere.html
I'm not sure if they'll fix your loading issue or not, but it would be
possible to also mod the JMS transport to behave differently under your
load problems also.
Hans Drexler wrote:
We have implemented a connection between MQ Series 5-7 and axis2 using
the axis2 1.4 JMS connectivity and a point-to-point set-up. The
implementation basically works, but some questions remain.
As long as we use a request/response pattern in the client connecting
to our service via jms all is well. In this scenario, the client
generates requests at a rate not higher than it receives results.
But if we split the client in a separate request Sender and Response
reader the following happens:
1) The request sender sends a fixed number (e.g. 10000) messages to
the MQ Series request queue.
2) Axis2 immediately starts eating messages out of the queue. Since
the JMS worker is single threaded by nature it can handle at most 1
request at a time. The JMS listener starts queueing messages read from
MQ Series at the maximum rate it can. This it can do faster than the
single JMS worker can handle the requests.
3) As a result, the queue inside axis2 grows until all available
memory is exhausted and then it crashes with an Out Of Memory
exception. All messages that were loaded in the axis2 queue but not
processed by the service are lost.
Would it not be better if the JMS Listener would not keep a (long)
queue of messages, but block instead until the previous request was
finished? That would keep the memory consumption of Tomcat constant
and avoids loosing messages. Maybe things are different in a
Publish/Subscribe scenario.
Also, in a post on axis2-dev, Asanka Perera says jms transport in
axis2 is deprecated. Is this true? Are there any recommendations
regarding the use of jms transport in combination with axis2?
Hans Drexler
Application Architect
Utrechtseweg 310
P.O. Box 3047
NL-6802 DA Arnhem
The Netherlands
Phone +31 (0)26 355 06 55
Fax +31 (0)26 355 06 66
[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
http://www.humaninference.com <http://www.humaninference.com/>
Human Inference B.V. - Chamber of Commerce NL - 09106800
The information contained in this communication is confidential and is
intended solely for the person and/or entity addressed above. If you
are not an intended recipient you are hereby notified that the content
of this message may not be disclosed, copied or distributed to any
other party than the addressee. Human Inference does not guarantee
that this communication is free of viruses or that other parties than
the intended recipient will not intercept this communication. Human
Inference assumes no liability for the proper and complete
transmission of the information contained in this communication or any
delay in the receipt of this communication by the addressee.
--
Anthony
-------------------------------------
Anthony Bull
Senior Developer
Black Coffee Software Ltd
PO Box 10-192 The Terrace
Wellington, New Zealand
[EMAIL PROTECTED]
Ph +64 4 472 8818
Fax +64 4 472 8811
-------------------------------------
www.bcsoft.co.nz
---------------------------------------------------------------
This email may contain confidential or privileged information,
and is intended for use only by the addressee, or addressees.
If you are not the intended recipient please advise the sender
immediately and do not copy, use or disclose the contents to
any other person or organisation.
Black Coffee Software Ltd accepts no responsibility for viruses
received with this email, or to any changes made to the original
content. Any views or opinions expressed in this email may be
personal to the sender and are not necessarily those of Black
Coffee Software Ltd.
---------------------------------------------------------------
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
