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| KAKEZ |
 Posted: Mon Sep 22, 2003 5:37 am Post subject: what value for MQMD field format if user data is binary? |
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Centurion
Joined: 10 Oct 2002
Posts: 117
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Hi,
1) I wonder about how to set up the 'format' field in MQMD when the user data is all binary?
2) the same question when we there is a MQRFH2 header after MQMD and before the user data all binary: same question about the 'format' field within the MQRFH2 header - how to set it up?
thanks for help
Jack |
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| KAKEZ |
| Posted: Mon Sep 22, 2003 6:31 am Post subject: |
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Centurion
Joined: 10 Oct 2002
Posts: 117
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I suggest the following mean to solve the pb (but not sure):
- MQMD format field = MQFMT_NONE
- not use of MQGMO_CONVERT when MQGETing the message at the receiving end
can we be sure to get the data as it was when created within the original message ?
<NB. the binary data is created by compression of normal data (.zip, ...)
thanks for advices>
Jack |
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| EddieA |
| Posted: Mon Sep 22, 2003 12:32 pm Post subject: |
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Jedi
Joined: 28 Jun 2001
Posts: 2453
Location: Los Angeles
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You could also use any non-reserved value. Anything that doesn't start with MQ.
If you wanted MQ to attempt a conversion, then you would build a Conversion Exit of the same name you use in the Format.
If the data is zipped, then the receiving program has to also do the conversion required, as well as unzipping the data. Assuming that the data needs conversion.
Cheers,
_________________
Eddie Atherton
IBM Certified Solution Developer - WebSphere Message Broker V6.1
IBM Certified Solution Developer - WebSphere Message Broker V7.0 |
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| KAKEZ |
| Posted: Mon Sep 22, 2003 10:55 pm Post subject: |
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Centurion
Joined: 10 Oct 2002
Posts: 117
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thanks Eddie for replying,
- but can you assure me that that the sending appli which Put a message with user data binary (after having compressed it for exemple) can do that just by setting up the MQMD field 'format' = MQFMT_NONE or other value not beginning with 'MQ'?
- then if the receiving appli wants to get the binary data from the message in its buffer without converting it but to keep it in the binary format to be able to send it to other appli , does MQGET without MQGMO_CONVERT is enought?
Jack |
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| EddieA |
| Posted: Tue Sep 23, 2003 8:19 am Post subject: |
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Jedi
Joined: 28 Jun 2001
Posts: 2453
Location: Los Angeles
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It doesn't matter what you have in the Format field when you PUT a message. MQ will NEVER change your data. So even if you declare it as MQSTR and put binary data, the PUT will work.
On the GET, the ONLY time MQ will attempt to 'mess' with your data is when you have the CONVERT option set. Withut that, again, it doesn't matter what's in the Format field.
Cheers,
_________________
Eddie Atherton
IBM Certified Solution Developer - WebSphere Message Broker V6.1
IBM Certified Solution Developer - WebSphere Message Broker V7.0 |
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| KAKEZ |
| Posted: Tue Sep 23, 2003 8:27 am Post subject: |
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Centurion
Joined: 10 Oct 2002
Posts: 117
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Thanks again Eddie, that's now much more clear for me
Jack |
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| jefflowrey |
| Posted: Tue Sep 23, 2003 11:32 am Post subject: |
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Grand Poobah
Joined: 16 Oct 2002
Posts: 19981
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| EddieA wrote: |
| On the GET, the ONLY time MQ will attempt to 'mess' with your data is when you have the CONVERT option set. Withut that, again, it doesn't matter what's in the Format field. |
I think I have to disagree with this. If the message passes through a channel with Sender Conversion turned on, the channel will do the data conversion regardless of what GET options are set by the receiving application.
_________________
I am *not* the model of the modern major general. |
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| EddieA |
| Posted: Tue Sep 23, 2003 3:34 pm Post subject: |
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Jedi
Joined: 28 Jun 2001
Posts: 2453
Location: Los Angeles
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Jeff,
Yep. I was only talking about Applications, as that was what the original question was all about.
At least anyone else picking up this thread will have all the 'scoop'.
But I also didn't do anywhere near Java, which has it's own set of challenges with data conversion, both on PUTs and GETs.
Cheers,
_________________
Eddie Atherton
IBM Certified Solution Developer - WebSphere Message Broker V6.1
IBM Certified Solution Developer - WebSphere Message Broker V7.0 |
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