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| joehuber |
 Posted: Fri Oct 08, 2004 11:43 am Post subject: Accessing version 2 messages from a z/OS server using C# |
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Newbie
Joined: 08 Oct 2004
Posts: 7
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I have a problem retrieving version 2 messages from a message queue on a z/OS MQ server. My application is written in C# and runs on Windows XP.
I have successfully used the application to retrieve version 2 formatted messages from a Windows MQ Server (I need version 2 because I need access to the Group Id). But when I point to a queue on the mainframe the MQMD always indicates the message is version 1 and has a 0 group id. I know that the message on the mainframe does, in fact, have version 2 information in it.
I am using the IBM MQ .NET wrapper classes. Below I have a sample of my code that uses the IBM.WMQ.MQMessage and IBM.WMQ.MQGetMessageOptions classes.
mqMsg = new MQMessage();
mqMsg.Format = MQC.MQFMT_STRING;
// Set the get message options
mqGetMsgOpts = new MQGetMessageOptions();
mqGetMsgOpts.WaitInterval = messageWaitMilliseconds;
mqGetMsgOpts.Options |= MQC.MQGMO_CONVERT;
mqGetMsgOpts.Options |= MQC.MQGMO_WAIT;
mqGetMsgOpts.Options |= MQC.MQGMO_SYNCPOINT;
mqGetMsgOpts.Options |= MQC.MQGMO_ALL_MSGS_AVAILABLE;
mqGetMsgOpts.Version = MQC.MQGMO_CURRENT_VERSION;
mqGetMsgOpts.MatchOptions = MQC.MQMO_NONE;
Note thtat I have also used MQC.MQGMO_VERSION_2 as the Version value and it made no difference.
I then get a message with the call:
mqQueue.Get( mqMsg, mqGetMsgOpts );
When the message returns the mqMsg instance has the group id set to all 0 and the mqGetMsgOpts instance has the group status set to not in a group. All the version 1 info is there such as the message id.
Do you see anything that I could be doing wrong? Remember that it works getting data from a queue on a Windows server but not from a queue on a z/OS server.
Do you know of any circumstances that would cause a version 2 message on the queue to return only version 1 data in the MQMD even though I am requesting version 2 within the GetMessageOptions?
Any help would be much appreciated (as I am pretty much stuck right now)!
Thanks,
Joe Huber |
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| EddieA |
| Posted: Fri Oct 08, 2004 12:36 pm Post subject: |
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Jedi
Joined: 28 Jun 2001
Posts: 2453
Location: Los Angeles
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| Quote: |
| But when I point to a queue on the mainframe the MQMD always indicates the message is version 1 |
This is because the MQMD you have defined in your program is set with Version 1.
From the depths of my memory, when I was at a previous client, I think they had exactly the same problem. (if not, it was very similar). The documentation implies that a Version 2 MQMD is used, but it isn't. You need to explicitly force the MQMD to a Version 2. Unfortunatley, I'm not a C (C++ or .NET) programmer, so I'm not too sure about the correct way of doing it.
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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| joehuber |
| Posted: Fri Oct 08, 2004 12:41 pm Post subject: MQMD Version changing |
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Newbie
Joined: 08 Oct 2004
Posts: 7
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Eddie,
Thanks for the reply. There is a version variable on the MQMessage class (independent of the version variable on the GetMessageOptions class). However, it is read-only. I guess I need more insight into the wrapper classes that IBM provides.
Does anyone have any more knowledge about the IBM provided .NET wrapper classes?
Thanks,
Joe |
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| kirani |
| Posted: Fri Oct 08, 2004 2:59 pm Post subject: |
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Jedi Knight
Joined: 05 Sep 2001
Posts: 3779
Location: Torrance, CA, USA
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I thought your post will get lost in the General Discussion forum, so I moved it to General MQ Support forum.
_________________
Kiran
IBM Cert. Solution Designer & System Administrator - WBIMB V5
IBM Cert. Solutions Expert - WMQI
IBM Cert. Specialist - WMQI, MQSeries
IBM Cert. Developer - MQSeries
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| joehuber |
| Posted: Mon Oct 11, 2004 4:38 am Post subject: I found the anwser! |
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Newbie
Joined: 08 Oct 2004
Posts: 7
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Thanks Kirani.
Amazing what a weekend of rest can do. First thing this morning I set about finding out how to set the MQMD version to 2 (remember I said I was setting the GetMessageOptions version to 2 but couldn't set the MQMessage version to 2 because it was read-only in the IBM provided MQMessage class). I found the ability to set MessageFlags on the MQMessage and there I was able to set MQMD_VERSION_2. And I then got a version 2 message back!!! I got farther in my process but still experienced a problem. However, now I think it is just a matter of getting the right flags set.
I appreciate everyones help. The one thing I could still use some help with is documentation. The IBM MQ .NET wrapper classes are basically undocumented (the help file is no better than the object browser). Is there documentation somewhere about these classes on the internet? A link would be much appreciated.
Thanks,
Joe |
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| jefflowrey |
| Posted: Mon Oct 11, 2004 4:45 am Post subject: |
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Grand Poobah
Joined: 16 Oct 2002
Posts: 19981
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| JasonE |
| Posted: Mon Oct 11, 2004 4:46 am Post subject: |
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Grand Master
Joined: 03 Nov 2003
Posts: 1220
Location: Hursley
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FYI the MD version is set to the lowest required to handle the api call you are making.
The Version field of the GetMessageOptions does appear to be publically changable, and as far as I can see would go into the api call.
You were after the groupid, part of the MQMessage object - This is returned from the server following the get, and as far as I can tell from a quick browse, is the copied from md returned from the get call, along with the version field.
Are you running server or client bindings. Take a trace, and look at the MD coming back from the MQGET
(If server : Search for the trace with your process name in the first 4 lines, then search that trace for " MQGET <<")
(If client : Search for " MQGET" and look backwards until you see a block of data which includes "MD ")
Paste the returned MD in here, or PM me a location I can ftp the traces + your source from and I'll take a look |
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