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ASP.NET HttpHandler - Concurrent requests

To solve a specific issue(maybe more about this in another post) we created a custom HttpHandler in ASP.NET. Inside this handler we need access to the session. Therefore we implemented the IRequiresSessionState marker interface:

The HttpHandler worked as expected until we started to increase the load. We noticed that a lot of requests remained pending…

This could be traced to the usage of the IRequiresSessionState that put an exclusive lock on the current session. As a consequence the # of concurrent requests for one user are restriced.

The good news is that another marker interface exists, IReadOnlySessionState, that does not acquire an exclusive lock. In case you only need to read data from the session state and don’t need to change any session data, you can switch to this interface:

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