Inconsistent behavior with the UpdateAsync and UpdateOne methods in C# MongoDB.Driver

Jason_Hill · 2024-02-26T11:08:36.643Z

We are utilizing the C# MongoDB.Driver library, specifically the latest version (2.23.1). However, we are experiencing intermittent and inconsistent behavior with the UpdateAsync and UpdateOne methods. These methods fail to update
the collection randomly, and no error is provided. This issue occurs unpredictably, and the update operation does not consistently succeed, even though no explicit error is reported.
Following is the sample Code

Env. .net Core 6.0 , c# mongodb Driver is 2.23.1 for both (Bson, Mongodb Driver)

var filters = Builders<Users>.Filter.Eq("Id", ObjectId.Parse(userAvailability.User_Id));
var update = Builders<Users>.Update.Set("Available", objAvailable);
var collection = _users.DBCollection();
var result = await collection.UpdateOneAsync(filters, update);

Kushagra_Kesav · 2024-03-07T07:12:01.974Z

Hi @Jason_Hill,

Welcome to the MongoDB Community forums

To assist you more effectively, could you please provide additional details? Here are some specific points that would be helpful:

Any error messages or exceptions encountered during the intermittent failures.
Server and driver version compatibility details (MongoDB server version and the specific version of the C# driver).
Server logs related to the update operation from your MongoDB instance.
A more extensive code snippet surrounding the UpdateOneAsync call.
Any further information on the MongoDB server’s status and connectivity.

These details will help the community members better understand and troubleshoot the issue you’re facing. Feel free to share any other relevant information that might be useful.

Best regards,
Kushagra

Luca_Scida · 2024-07-18T11:19:27.943Z

Hi,
I have same problem. My solution is:

.Net Core 6.0
MongoDB.Driver 2.25.0
DocumentDB (with MongoDB compatibility) on AWS. Engine AWS version 4.0.0

This happening on Client production environment

Serge_Saintonge · 2025-03-24T13:07:35.759Z

Intermittent Update Failure with FindOneAndReplaceAsync in MongoDB .NET Driver

I’m working on a project using .NET 9 with MongoDB.Bson 3.2.1 and MongoDB.Driver 3.2.1. I’ve implemented a method to update a document in MongoDB using FindOneAndReplaceAsync, and I’m running into an issue where the update doesn’t always persist in the database, even though the method returns the updated document. Here’s the code I’m using:
public virtual async Task ReplaceOneAndReturnNewVersionAsync(TDocument document)
{
var filter = Builders.Filter.Eq(doc => doc.Id, document.Id);
return await _collection.FindOneAndReplaceAsync(filter, document, new FindOneAndReplaceOptions { ReturnDocument = ReturnDocument.After });
}
(Note: I’ve set the ReturnDocument.After option to return the updated document, as implied by the method name.)

The Problem

Most of the time, this works fine—the method returns the updated document as expected. However, about 1 out of 10 times (sometimes 1 out of 4 or 5), when I check the database afterward, the old version of the document is still there. This behavior is random and inconsistent, making it hard to pinpoint the cause.

Any advice on how to troubleshoot or resolve this would be greatly appreciated. Thank you!