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| sharonv |
 Posted: Thu Jan 16, 2014 2:47 am Post subject: message delay |
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Apprentice
Joined: 03 Feb 2011
Posts: 27
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Hi
I'm using MQ 7.0.1.11
We have a queue which we set up the performance event
the high depth was set to 1 to each time a meesage enters the event is created
we listen to the event queue and catch the event message then we notify our application that a message is in the queue
the application does mqget and then also check for the current queue depth to see if any more messages exists
we noticed the following , a mesage is sent ( small one no loads)
the event is created , the application does the mq get and recieves no messages then check the queue depth and it is 1
it does a loop like that and we find out it takes about half a second until the message appears in the queue
we have several queue manager in which we dont see this delay
any idea anyone ? |
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| exerk |
| Posted: Thu Jan 16, 2014 3:59 am Post subject: Re: message delay |
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Jedi Council
Joined: 02 Nov 2006
Posts: 6339
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| sharonv wrote: |
| ...we listen to the event queue and catch the event message then we notify our application that a message is in the queue the application does mqget and then also check for the current queue depth to see if any more messages exists |
Why? Why does the app not do a GET with wait, or why do you not trigger the application?
| sharonv wrote: |
| ...we noticed the following , a mesage is sent ( small one no loads) the event is created , the application does the mq get and recieves no messages then check the queue depth and it is 1 it does a loop like that and we find out it takes about half a second until the message appears in the queue we have several queue manager in which we dont see this delay |
Probably because the message has not been committed by the putting application.
_________________
It's puzzling, I don't think I've ever seen anything quite like this before...and it's hard to soar like an eagle when you're surrounded by turkeys. |
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| zpat |
| Posted: Thu Jan 16, 2014 6:05 am Post subject: |
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Jedi Council
Joined: 19 May 2001
Posts: 5866
Location: UK
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Ex-erk is correct.
A conventional triggered queue approach would be better. Or for high volumes using long running application with a MQGMO_WAIT.
_________________
Well, I don't think there is any question about it. It can only be attributable to human error. This sort of thing has cropped up before, and it has always been due to human error. |
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| sharonv |
| Posted: Sun Jan 19, 2014 12:16 am Post subject: |
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Apprentice
Joined: 03 Feb 2011
Posts: 27
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Hi
The application was writen long time ago ,
and it will take time to change it , as it is running in production mode
can you explain why there is half a second delay between the time
we see the current depth increasing and when the message is available
is there anything to do with the current situation
is it possible that the current depth will increase and yet the message will be in the queue yet ? |
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| zpat |
| Posted: Sun Jan 19, 2014 1:07 am Post subject: |
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Jedi Council
Joined: 19 May 2001
Posts: 5866
Location: UK
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The usual reason for any disparity in queue depth and the messages available on the queue is due to uncommitted messages.
_________________
Well, I don't think there is any question about it. It can only be attributable to human error. This sort of thing has cropped up before, and it has always been due to human error. |
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| PeterPotkay |
| Posted: Sun Jan 19, 2014 6:33 am Post subject: |
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Poobah
Joined: 15 May 2001
Posts: 7722
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Trigger messages don't get committed until the app messages that generated them is committed - which avoids apps from getting triggered prematurely.
Apps that sit on a queue and MQGET with wait don't receive the message until the message is committed.
Use Event messages and/or checking queue depth to see if there is a message to get is a bad design.
A half second delay is causing you a problem, or its just a curiosity you would like to understand?
_________________
Peter Potkay
Keep Calm and MQ On |
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| bruce2359 |
| Posted: Sun Jan 19, 2014 6:48 am Post subject: |
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Poobah
Joined: 05 Jan 2008
Posts: 9469
Location: US: west coast, almost. Otherwise, enroute.
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| sharonv wrote: |
The application was writen long time ago ,
and it will take time to change it , as it is running in production mode |
Has it always behaved with this delay? Or, is this delay new behavior? When was the program last compiled?
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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. |
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