SharePoint 2013: Max pool size was reached

Thomas Stessl 61 Reputation points
2020-08-04T06:00:01.28+00:00

Hi,

We have an SP2013 with 3-tier running for several years now, suddenly i get the following error after some time:
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.

Only a IISReset helps for a certain time nad i cant figure out the problem for this.

What can be the reason or how can i detect the reason behind this problem (too many users? ACL to big in a list? ...)

SQL Server
SQL Server
A family of Microsoft relational database management and analysis systems for e-commerce, line-of-business, and data warehousing solutions.
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SharePoint Server Management
SharePoint Server Management
SharePoint Server: A family of Microsoft on-premises document management and storage systems.Management: The act or process of organizing, handling, directing or controlling something.
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Accepted answer
  1. m 4,266 Reputation points
    2020-08-04T09:29:14.47+00:00

    Hi ThomasStessl-3946,

    What can be the reason or how can i detect the reason behind this problem (too many users? ACL to big in a list? ...)

    The default connection pool size is 100. When we go to the connection pool to select a connection for reuse, we find that all connections are in use. In this case, it will wait for the Connection Timeout time. If during this time, it has been unable to get a reusable connection from the connection pool, the above error will be reported. The solution is as follows:

    1. Check whether all connections are normally opened and closed. Connections that are not closed cannot be reused. Most of the above-mentioned errors are caused by this reason.
    2. In addition, we can also modify the connection string to increase "Max Pool Size", for example, set it to "Max Pool Size"=200.
    3. Only in extreme cases, we can modify the connection string to cancel the connection pool. This certainly solves the problem, but it affects performance.

    More information: The-timeout-period-elapsed-prior-to-obtaining-a-co, sharepoint-sql-db-blocking-issues

    If the response helped, do "Accept Answer" and upvote it.

    BR,

    Mia


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