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| psandip |
 Posted: Mon Oct 19, 2009 1:07 am Post subject: Using shared variables with additional instances |
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Novice
Joined: 11 Aug 2006
Posts: 17
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Hi,
I am using a shared variable for my message flow. The message flow generated a filename based on timestamp and assigns this name to the shared variable. A check is made within the compute node to see whether the shared variable is null or does it have a value. If it is null, the the filename is generated and assigned to it else, no need to assign a new name. Now suppose 10 instances of this message flow is to be deployed. once the shared variable is populated with a filename, can the other 9 flows access this value or they see it as null?
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With Best Regards,
Sandeep |
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| WMBDEV1 |
| Posted: Mon Oct 19, 2009 1:37 am Post subject: |
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Sentinel
Joined: 05 Mar 2009
Posts: 888
Location: UK
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| smdavies99 |
| Posted: Mon Oct 19, 2009 1:42 am Post subject: |
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Jedi Council
Joined: 10 Feb 2003
Posts: 6076
Location: Somewhere over the Rainbow this side of Never-never land.
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Did you try it for yourself? This is a good way to learn.
Also, don't double post.
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MQSI/WBI/WMB/'Thingy' User since 2002
Linux user since 1995
Every time you reinvent the wheel the more square it gets (anon). If in doubt think and investigate before you ask silly questions. |
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| psandip |
| Posted: Mon Oct 19, 2009 1:48 am Post subject: |
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Novice
Joined: 11 Aug 2006
Posts: 17
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@WMBDEV1
Looked into the manul and checked that shared variables are shared across instances. Thanks.
@ smdavies99
I didn't double post on purpose. I got a timeout in my first attempt and then wnet back and resubmitteed. Then I saw the entire thing being doubly posted. I even tried to delete the earlier post but couldn't. |
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| fjb_saper |
| Posted: Mon Oct 19, 2009 2:53 am Post subject: |
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Grand High Poobah
Joined: 18 Nov 2003
Posts: 20768
Location: LI,NY
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You might also want to look up the word ATOMIC.
When working with a shared variable and multiple instances of the flow you have to consider thread safety... 
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| Sam Uppu |
| Posted: Wed Oct 21, 2009 7:41 am Post subject: |
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Yatiri
Joined: 11 Nov 2008
Posts: 610
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To add it to the FJs point, you need to use BEGIN ATOMIC and END ATOMIC in your flow.
If I remember correctly, there should be a sample out there in the WMB examples in Toolkit 6.1/ 6.0
Thanks. |
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| MQEnthu |
| Posted: Wed Oct 21, 2009 11:18 pm Post subject: |
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Partisan
Joined: 06 Oct 2008
Posts: 329
Location: India
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| psandip wrote: |
| Looked into the manul and checked that shared variables are shared across instances. |
Also note that you cannot share variables across execution groups.
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