SqlException from Entity Framework - New transaction is not allowed because there are other threads running in the session

🚨 Solving the "New transaction is not allowed because there are other threads running in the session" error 🚨

If you're encountering the SqlException with the message "New transaction is not allowed because there are other threads running in the session" when running your code, don't worry! You're not alone. This error is commonly seen when working with Entity Framework and multiple threads.

In this blog post, we'll explore the cause of this issue and provide some easy solutions to fix it. Let's dive in! 💻🔍

Understanding the problem

This error occurs when multiple threads are trying to access the same database context simultaneously. In your code example, it seems that the SyncFeeds() method is being called by multiple threads, leading to the error.

Solution 1: Using a new context for each thread

One way to solve this issue is to create a new instance of the database context (RivWorks.Model.Negotiation.RIV_Entities) for every thread. By doing this, each thread will have its own isolated context and won't interfere with others.

To implement this solution, modify your code as follows:

private void SyncFeeds()
{
    using (var dbRiv = RivWorks.Model.Stores.RivEntities(AppSettings.RivWorkEntities_connString))
    using (var dbFeed = RivWorks.Model.Stores.FeedEntities(AppSettings.FeedAutosEntities_connString))
    {
        // Your existing code...
        // Remember to update all usages of _dbRiv and _dbFeed to dbRiv and dbFeed, respectively.
    }
}

By encapsulating the usage of the context within a using statement, the context will be disposed of automatically after each thread completes its work.

Solution 2: Synchronizing access to the shared context

Another approach is to synchronize access to the shared context to ensure that only one thread can access it at a time. This can be achieved by using a lock or other synchronization mechanisms.

Here's an example of how you can modify your code to implement this solution:

// Declare a private object for locking
private object _lockObject = new object();

private void SyncFeeds()
{
    lock (_lockObject)
    {
        // Your existing code...
        // Make sure to synchronize all usages of _dbRiv and _dbFeed within the lock block.
    }
}

By using the lock statement with a shared lock object (_lockObject), the threads will take turns executing the code within the lock block, ensuring that only one thread accesses the context at a time.

The choice is yours! 🤔

Now that you have two solutions at your disposal, you can choose the one that best fits your needs. Both solutions provide a way to address the "New transaction is not allowed because there are other threads running in the session" error and allow your code to run smoothly.

Remember, if you're working with multiple threads and a shared context, it's essential to handle concurrency issues to prevent unexpected errors like this one.

So what are you waiting for? Try out one of these solutions and get your code back on track! Happy coding! 👩‍💻🚀

Have you encountered this error before? Share your experience with us in the comments below! Let's learn from each other and conquer those pesky bugs together!