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| Multi Message Problem - PROPAGATE |
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| aspre1b |
 Posted: Fri Oct 31, 2008 5:52 am Post subject: Multi Message Problem - PROPAGATE |
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Voyager
Joined: 05 Jul 2007
Posts: 78
Location: Coventry, UK
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I’m looking for a little guidance, my scenario is this:
I have a system that kicks out 19 different event messages in cobol copybook format. I have modelled these and I have no problem processing these (I convert them into a canonical XML format and publish them).
I have another type of event message (multi message) that is a concatenation of any of the previous 19 message types. It also has a header (start of the data, not in the usr folder) that describes the number of messages, length of each message and the type of each message.
I have successfully created an MRM to model the multi message format.
[No of types][TypeLength][Type,Length][Type,Length][Type,Length][ FLS DATA / RestMsg]
I plan to chop up the multi message into many messages using PROPAGATE and process them the same as the other 19 event messages. I would prefer to convert each message back into a BLOB and send it back into the event dispatcher.
The alternative was to populate each message type manually, but this would take a while to code.
Sample of my code below:
| Code: |
CALL CopyMessageHeaders();
/**********************************************************************************************************************
* msg = length of fixed length message 0000
* restMsg = rest of the message(s) minus the header information which includes the fixed length and data type
* msgType = message type 0000
*
* [No of types][TypeLength][Type,Length][Type,Length][Type,Length][ FLS DATA / RestMsg]
***********************************************************************************************************************/
DECLARE inRef REFERENCE TO InputRoot.MRM;
DECLARE msgLength INTEGER;
DECLARE myChar, restMsg, msgType,messageType CHARACTER;
DECLARE msgSetID,formatType,BH_Class CHARACTER;
DECLARE myBlob,myBlob2 BLOB;
DECLARE blobLength,restMsgLength INTEGER;
DECLARE blobRef REFERENCE TO Environment.BLOB.BLOB;
SET restMsg = inRef.REST;
--Set headRef to the current msg
DECLARE headRef REFERENCE TO inRef.MSG_HEAD[1];
--Cycle through msg headers and extract message from restMsg
WHILE LASTMOVE(headRef) DO
SET msgLength = headRef.MLENGTH;
SET msgType = TRIM(headRef.MTYPE);
--Get current msg from restMsg
SET myChar = SUBSTRING (restMsg FROM 1 FOR msgLength);
SET OutputLocalEnvironment.myChar = myChar; -- maybe not needed
--Perform msgType and msgSet lookup
CALL LookupMsgType(msgType,msgSetID,formatType,BH_Class,messageType);
--Set BH_Class field of the extracted msg
SET "OutputRoot"."MQRFH2"."usr"."BH_Class" = BH_Class;
SET blobLength = 0;
SET restMsgLength = 0;
SET blobLength = LENGTH(blobRef);
SET restMsgLength = LENGTH(inRef.REST);
SET OutputRoot.Properties.MessageDomain = 'BLOB';
--Remove current msg from restMsg
SET restMsg = SUBSTRING(restMsg FROM (msgLength + 1));
--Propagate msg and reset the environment tree
CALL PropagateEnvironment(inRef);
CALL CopyMessageHeaders();
--Move headRef to next msg header
MOVE headRef NEXTSIBLING REPEAT TYPE NAME;
END WHILE;
RETURN FALSE; |
NB: I've got a copy of the original BLOB multi message in the environment tree.
Any help would be appreciated. |
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| aspre1b |
| Posted: Fri Oct 31, 2008 6:32 am Post subject: |
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Voyager
Joined: 05 Jul 2007
Posts: 78
Location: Coventry, UK
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| Can an administrator please delete this as it should be in the WBIMB section. |
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| kimbert |
| Posted: Fri Oct 31, 2008 2:51 pm Post subject: |
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Jedi Council
Joined: 29 Jul 2003
Posts: 5542
Location: Southampton
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If you are trying to make the parsing easy, then your 'multi-message' format is not ideal. This would be better:
| Code: |
| MessageType1, Message1, MessageType2, Message2, MessageType3, Message3... |
Note the following:
- Each message type is grouped with its message
- There is no need for a length field. The MRM's on-demand parsing ensures that parsing stops at the end of each message ( assuming that none of your messages ends with a variable-length field ).
If you use the structure suggested above, then you can use the Message Alias / Interpret Value As method to identify each message. See here for details: http://publib.boulder.ibm.com/infocenter/wmbhelp/v6r1m0/topic/com.ibm.etools.mft.doc/ad00761_.htm
Your message model would look something like this:
| Code: |
MultiMessage
Group minOccurs=0 maxOccurs=-1
element Name="MessageType" InterpretValueAs="Message Identity"
Group Composition="InnerMessage" |
The advantage of this approach is that you can throw away all of your ESQL parsing code, and let the MRM parser take the strain. I'm assuming two things here:
- you have complete control of the multi-message format
- you are on v6 or later. |
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| aspre1b |
| Posted: Sun Nov 02, 2008 11:38 pm Post subject: |
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Voyager
Joined: 05 Jul 2007
Posts: 78
Location: Coventry, UK
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Thanks for your reply, unfortunately I'm using Broker 5.3 CSD 8, MQ 5 CSD 12.
I thought I had put this on the original post, it looks like I forgot. |
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| kimbert |
| Posted: Mon Nov 03, 2008 2:29 am Post subject: |
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Jedi Council
Joined: 29 Jul 2003
Posts: 5542
Location: Southampton
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| If your message contains only character data then you can do the same trick using TDS instead of CWF. In fact, the v6.0 message alias/message identity feature is simply an extension of the v5 TDS message key feature. |
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| aspre1b |
| Posted: Tue Nov 04, 2008 2:35 am Post subject: |
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Voyager
Joined: 05 Jul 2007
Posts: 78
Location: Coventry, UK
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Unfortunately I do not have control of the message. It is fixed to be this format:
[No of types][TypeLength][Type,Length][Type,Length][Type,Length][ FLS DATA / RestMsg] |
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| aspre1b |
| Posted: Thu Nov 06, 2008 7:50 am Post subject: |
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Voyager
Joined: 05 Jul 2007
Posts: 78
Location: Coventry, UK
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I've simply propagated into the MRM domain, using my existing copybook. There was a problem with my copybook, which I had to twiddle  to get working, but it all works fine now.
Cheers for your help. |
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