Time out exception in SSIS Dataflow task

Description: System.InvalidOperationException: Timeout expired.  The timeout period elapsed prior to obtaining a connection from the pool.  This may have occurred because all pooled connections were in use and max pool size was reached

This is the detailed exception.  Why do we generally get this exception and how can we avoid it.
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Right-click in your connection on connection manager, and select tab ALL

Try to change the values of connection, mainly timeout.. as you can see in the image

Make sure you and other applications are closing connections. You know that piece of code at the end of a sql connection where we write something like:
It sounds like you have a leak somewhere. With every open should also be a close. Look for open connections at the database level. See if you can tell what is leaving the connections open.

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Great resource on connection pooling and connection leaks.
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akulasAuthor Commented:
Thank you Experts for your suggestions.  But I cannot reproduce this error every time.  It happens very randomly.  I will check for the connections I opened and I will close them manually.  I am pretty sure that I did them.  

I will make the timeout to 0 as you have mentioned.   Can you tell me what this actually means?
Randomly suggests you have a leak. Connections are being opened and not closed. Next time you get the error, run the sp_who stored procedure to get some session details.
Dear akulas,
Exist in this connection three timeouts: (General, Connect and Command)

General should be the overall timeout for the connection.  
Connect should be just for the connection.  If the connection hasn't been established by the timeout (or the default), it will stop trying to connect.  
Command timeout is likely the timeout SSIS will wait for a command to complete.


I have found that when you use the connection type: ADO, the timeout is automatically set to 30 seconds (Regardless of which timeout option you manually change). I had al 3 timeout options set to 0, which should indicate that no timeout is required.
I fixed my timeout problem by changing the connection type to "OLE DB".
I hope this helps someone.
Anthony PerkinsCommented:
>>ADO, the timeout is automatically set to 30 seconds <<
That really depends on whether you are talking about ADO or ADO.NET.  In ADO both the Connection and Command default Timeout was 30 seconds.  In ADO.NET the Connection default Timeout is set to a more reasonable 15 seconds. But in both ADO and ADO.NET you can programatically set it to any value you chosse including 0 (infinite)
We're having this issue on the Execute SQL task in SSIS.  I was under the impression that it would close the connection itself- one of the benefits of the connection manager in SSIS?

Once it reaches the 100 limit, it gives us the timeout error.  Does anyone have insight to:
1. Why this isn't being managed through SSIS?
2. How we can close the connections?

Anthony PerkinsCommented:

You may have better luck if you post your own question, rather than piggy-backing on this closed thread.
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