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| wskibum |
 Posted: Tue Jun 12, 2012 7:49 am Post subject: Getting message and header size |
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Apprentice
Joined: 03 Jul 2008
Posts: 38
Location: Northern California
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I am trying to calculate band width requirements and part of that is the size of messages. I have been surfing for several days and found tons of info about headers and message in general but nothing on a quick way to look at a message and get size info.
Can anyone help me out?
Thanks |
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| mqjeff |
| Posted: Tue Jun 12, 2012 8:04 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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You mean other than the field in the MQMD that tells you how long the data is?
Are you trying to find out how big a specific message is?
Or how big "random generic MQ messages that might flow over a given channel" are?
In general, the application teams developing your MQ applications should have a firm idea of how big the messages they send and consume are. YMMV. |
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| wskibum |
| Posted: Tue Jun 12, 2012 8:15 am Post subject: |
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Apprentice
Joined: 03 Jul 2008
Posts: 38
Location: Northern California
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Thanks for the reply. Yes they gave me some data that I would like to verify.
I guess the real question is what is the average header size |
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| exerk |
| Posted: Tue Jun 12, 2012 8:32 am Post subject: |
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Jedi Council
Joined: 02 Nov 2006
Posts: 6339
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| wskibum wrote: |
| I guess the real question is what is the average header size |
No, the question remains as "what is the average message size?". The header size is fixed (and RFH don't count because it's part of the payload).
_________________
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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| wskibum |
| Posted: Tue Jun 12, 2012 8:38 am Post subject: |
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Apprentice
Joined: 03 Jul 2008
Posts: 38
Location: Northern California
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| Great. What is the fixed header size? |
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| mqjeff |
| Posted: Tue Jun 12, 2012 8:39 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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| wskibum wrote: |
| Yes they gave me some data that I would like to verify. |
You mean, for example, by reading and learning about all of the statistics that MQ provides you for monitoring things like channels?
Or merely by dumping out the contents of a bunch of messages and adding up the data length field from the mqmds?
What is your end result out of this exercise? |
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| wskibum |
| Posted: Tue Jun 12, 2012 8:46 am Post subject: |
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Apprentice
Joined: 03 Jul 2008
Posts: 38
Location: Northern California
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I had the network folks approach me last Friday for information the need to do sizing on a dedicated network connection they are planning to put in. They need this info today.
The DEV folks were pretty evasive about the message size they are putting out and I was unable to track down specific info on the header size. Was hoping there would be a quick way for me to look at several hundred messages and get some idea of the average size. Then based on the the projected number of messages I can give some workable data to the network folks.
Thanks |
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| exerk |
| Posted: Tue Jun 12, 2012 8:50 am Post subject: |
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Jedi Council
Joined: 02 Nov 2006
Posts: 6339
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| wskibum wrote: |
| Great. What is the fixed header size? |
Without looking in the manual I couldn't tell you, but I do know there's an extra header (XQH) for transmission headers (which adds 4KB?).
_________________
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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| mqjeff |
| Posted: Tue Jun 12, 2012 8:57 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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| wskibum wrote: |
I had the network folks approach me last Friday for information the need to do sizing on a dedicated network connection they are planning to put in. They need this info today.
The DEV folks were pretty evasive about the message size they are putting out and I was unable to track down specific info on the header size. Was hoping there would be a quick way for me to look at several hundred messages and get some idea of the average size. Then based on the the projected number of messages I can give some workable data to the network folks.
Thanks |
Yeah, use amqsbcg to dump out messages. Write a bit of perl or other scripting to pull out and sum up the mqmd message length fields.
Then add a fudge factor to cover the xqh.
And then warn the network admins that this likely represents a median case, and not a high water mark or a low water mark. |
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| mqjeff |
| Posted: Tue Jun 12, 2012 9:00 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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Oh, and remember that MQ channels are tunable, so you can alter things like batch size and etc. to use more or less bandwidth at a given point.
I'd be tempted to push back on the network admins and ask what the economic impact of their sizing is, and find out if they're counting peanuts in a bag when you're feeding an elephant. I.e. it's nice if they're doing due-diligence, but if the effort outweighs the benefit, they're wasting money. |
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| wskibum |
| Posted: Tue Jun 12, 2012 10:23 am Post subject: |
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Apprentice
Joined: 03 Jul 2008
Posts: 38
Location: Northern California
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| Thank you very much guys for all your help! |
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