MQ

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  • 1.  Use of MQ and AMQP clients pub/sub to same topic ok?

    Posted Thu October 08, 2020 02:50 PM
    I'm looking into a use case where I want multiple clients to interact with the same MQ topic string.  Some clients will use the IBM MQ ibmmq client and others will use an AMQP client.  I was curious to see if I could configure the MQ server with two channels (one MQ and one not) to the same topic.  This wasn't too difficult and indeed works having diverse clients connecting to the same endpoint.

    * Channel definitions:
    DEFINE CHANNEL('APP.AMQP') CHLTYPE(AMQP) PORT(5672) REPLACE
    START CHANNEL('APP.AMQP')

    DEFINE CHANNEL('APP.SVRCONN') CHLTYPE(SVRCONN) REPLACE

    * Topic definitions:
    DEFINE TOPIC('SMS') TOPICSTR('sms-messages') REPLACE
    I'm using the default ports (1414 for MQ client and 5672 for AMQP client).

    This seems like a reasonable configuration, but since I'm new to MQ I want to make sure it is an ok practice.  Are there any concerns or gotchas to be aware of with doing this?

    Thanks,

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    Jim Creasman
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  • 2.  RE: Use of MQ and AMQP clients pub/sub to same topic ok?

    Posted Fri October 09, 2020 08:36 AM
    Hi Jim
    Some time in the past, IBM published a PDF about the theory of Pub/Sub
    You may wanna consume the theory on a rainy day unless you already consumed it.
    The document is a little out of date.
    ftp://public.dhe.ibm.com/software/integration/support/supportpacs/individual/ma0dintr.pdf

    The channels itself have nothing to do with pub/sub.
    If you pay IBM to support you, it is best to ask IBM if that model is supported - it should be.
    I see one risk.
    What ever your AMQP Clients are made of (Java, Node, Python, C++ ) must communicate on port 5672 that is 100% compliant with IBMs implementation of AMQP Listener.
    AMQP is like HTTP or IMAP an openly defined protocol that requires implementation from software vendors.
    If you encountered any issues, AMQP Client and AMQP Listener might blame each other for having the bug.
    If both is coming from the same vendor - the vendor is accountable.
    If your AMQP Client software is also coming from IBM one could be wondering - why not do everything on 1414 or 5672.
    Those who are monitoring firewalls and network traffic appreciate if as many ports as possible are kept closed.
    The less variety you have the lower your TCO (claim without evidence).

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    Matthias Jungbauer
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  • 3.  RE: Use of MQ and AMQP clients pub/sub to same topic ok?

    Posted Fri October 09, 2020 09:33 AM
    Hi Jim, I hope you are doing well! Can we know how many clients you plan on having connecting to the same topic?

    MQ pub/sub resource consumption grows linearly, may become an issue when you have 100s of consumers. MQ creates a clone of the message for each consumer.



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    Bruno Rodrigues Neves
    Integration Specialist
    IBM
    Tampa FL
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  • 4.  RE: Use of MQ and AMQP clients pub/sub to same topic ok?

    Posted Sun October 11, 2020 05:52 PM
    Bruno,

         In this case there is only a single subscriber and multiple publishers to the topic.  I don't foresee the number of publishers growing to more than 10-15 in this case.  Does the concern you mention apply to both publishers and subscribers?

    Jim

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    Jim Creasman
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  • 5.  RE: Use of MQ and AMQP clients pub/sub to same topic ok?

    Posted Mon October 12, 2020 12:10 PM
    Hi Jim, if the environment is sized appropriately you should be fine here... By appropriately I mean taking into account the number of consumers, the size of the messages, how long it takes for the consumers to consume the messages, etc, anything that could drive disk utilization up.

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    Bruno Rodrigues Neves
    Integration Specialist
    IBM
    Tampa FL
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  • 6.  RE: Use of MQ and AMQP clients pub/sub to same topic ok?

    Posted Mon October 12, 2020 09:57 AM

    Hi Jim

    I do not generally see a problem with this.  In the simplest case each MQ and AMQP client would have a subscription to the topic. Then as messages get published to the topic each client would get a copy of the message.

    From the IBM MQ queue manager point of view an AMQP client subscription is just like a regular MQ client subscription; but the subscription name is constructed by the MQ AMQP service from the AMQP client subscription request information (See IBM MQ Knowledge Center topic: Interoperability between IBM MQ Light and Apache Qpid JMS applications for the subscription name formats)



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    Chris White
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