| Author |
Message
|
| DrajMQ |
 Posted: Mon Mar 31, 2014 7:51 pm Post subject: |
 |
|
Newbie
Joined: 29 Mar 2014
Posts: 7
|
Thanks tczielke.
That was a great explanation for Endianess. Also the clue was fantastic. I checked back for the version, it was 16777216.
(16777216) in decimal = (1000000) in hex.
This will be very helpful for future reference. Thanks a lot.
Thanks,
Dhiraj Khot |
|
| Back to top |
|
 |
| PaulClarke |
| Posted: Tue Apr 01, 2014 12:19 am Post subject: |
|
|
Grand Master
Joined: 17 Nov 2005
Posts: 1002
Location: New Zealand
|
DrajMQ,
Isn't your question covered in the first bullet?
| Quote: |
| Space previously occupied by a message which has now been removed from the queue using MQGET is immediately available for re-use by ANOTHER MESSAGE ON THE SAME QUEUE |
Perhaps I misunderstood the question but essentially the QM will over-write the queue file if it can.
Cheers,
P.
_________________
Paul Clarke
MQGem Software
www.mqgem.com |
|
| Back to top |
|
|
| DrajMQ |
| Posted: Tue Apr 01, 2014 4:34 am Post subject: |
|
|
Newbie
Joined: 29 Mar 2014
Posts: 7
|
Thanks Paul.
Is there any specific reason u mentioned the below if -
QM will over-write the queue file "if it can".
Are there any factors for the queue manager's behavior for the above.
The reason for my that question is because in our Prod environment the Q file size is not getting over-written (this behavior is intermittent), but in TEST environment it is getting over-written.
Thanks,
Dhiraj Khot |
|
| Back to top |
|
|
| mqjeff |
| Posted: Tue Apr 01, 2014 5:33 am Post subject: |
|
|
Grand Master
Joined: 25 Jun 2008
Posts: 17447
|
| The size of the file won't change if portions of it are being reused. |
|
| Back to top |
|
|
| mqjeff |
| Posted: Tue Apr 01, 2014 5:33 am Post subject: |
|
|
Grand Master
Joined: 25 Jun 2008
Posts: 17447
|
| The size of the file won't change if portions of it are being reused. |
|
| Back to top |
|
|
| PaulClarke |
| Posted: Tue Apr 01, 2014 5:54 am Post subject: |
|
|
Grand Master
Joined: 17 Nov 2005
Posts: 1002
Location: New Zealand
|
DrajMQ,
No, I didn't mean anything particular by the phrase "if it can". I merely meant that that when the Queue Manager is looking for somewhere to store a message it will try ot re-use file space already allocated first. It would surprise me if there was a difference in behaviour in test and production if the conditions are the same. ie. same MQ version, same tuning - ie checkpoint frequency, same queue usage pattern etc.
Cheers,
Paul.
_________________
Paul Clarke
MQGem Software
www.mqgem.com |
|
| Back to top |
|
|
| PeterPotkay |
| Posted: Tue Apr 01, 2014 8:38 am Post subject: |
|
|
Poobah
Joined: 15 May 2001
Posts: 7722
|
| DrajMQ wrote: |
The reason for my that question is because in our Prod environment the Q file size is not getting over-written (this behavior is intermittent), but in TEST environment it is getting over-written.
|
What evidence do you have that made you come to this conclusion?
_________________
Peter Potkay
Keep Calm and MQ On |
|
| Back to top |
|
|
| bruce2359 |
| Posted: Tue Apr 01, 2014 9:51 am Post subject: |
|
|
Poobah
Joined: 05 Jan 2008
Posts: 9472
Location: US: west coast, almost. Otherwise, enroute.
|
| PeterPotkay wrote: |
| DrajMQ wrote: |
The reason for my that question is because in our Prod environment the Q file size is not getting over-written (this behavior is intermittent), but in TEST environment it is getting over-written.
|
What evidence do you have that made you come to this conclusion? |
I've seen this difference in behavio(u)r before.
Applications MQPUT messages buffers in WMQ's virtual storage. For many application types, the consuming app MQGETs the messages from buffers immediately. These messages will likely not be written to queue-holding disk filesystem.
For messages not consumed immediately, WMQ buffer-management software will move messages from virtual storage to the queue-holding disk file system to harden them. Later, as messages are consumed from disk, that space on disk will be marked as re-usable.
TEST and PROD have differing activity levels. A developer testing the producing app will test it many times, possibly with no consumer running.
WMQ makes no guarantee how, when, or under what circumstances, all of this back-end magic takes place.
_________________
I like deadlines. I like to wave as they pass by.
ב''ה
Lex Orandi, Lex Credendi, Lex Vivendi. As we Worship, So we Believe, So we Live. |
|
| Back to top |
|
|
|
|
