Device Sync (Pre Partition and Flexible sync) Stopped Working

[Delphi_Measurement]

Hi all,

I’m placing this topic as a helper for anyone who seems to be having issues with or is unaware of any issues regarding device sync for MongoDB. As everyone is aware, recently MongoDB has announced the deprecation of the device sync service. This will come into place from September 2025. They state that all services will remain operational until then.

However, this is not the case I have 6 device sync applications. 3 were created before the partition or flexible options within the deployment methods. The next three were deployed with partition as the main method for device sync functionality.

The important note here is that the first 3 applications have stopped working, resulting in my mobile applications failing. On user authentication for these apps, I utilise the “DownloadAndSync() and UpdateAndSync()” SDK functions. This may be because I didn’t update them to use partition keys or flexible sync functionality. This was and still isn’t a requirement for my apps so I don’t see why I need to change my whole application to handle something I wouldn’t use.

I originally came across this as soon as I learnt about the deprecation because not only did they announce the deprecation but a lot of UI changes had occurred and I was concerned that some functionality would have been changed too. Testing all my applications I stumbled across the issue where when calling “DownloadAndSync()” My application would just “Do nothing” There were no errors that came back (Probably could have handled error handling more effectively). I tried to contact MongoDB support for assistance not only to find my Device Sync Apps (the change of UI made it hard to find the apps) but also if any functionality had been changed. After a few hours, I finally got a reply noting that no functionality had been changed and it was only a notice that the service would stop in the future. This didn’t explain why applications had just stopped.

I finally got a response to the location of my previous device sync applications. and when logging into each one I found the three I had originally created were reporting an error in their logs.

Error:

Atlas Device Sync has been deprecated

Remote IP Address:
xx.xx.xx.xx

This error looks like the functionality has actually been stopped?

Each time I called “DownloadAndSync or UpdateAndSync”, this error would pop up in the App logs. Now I’m not sure if there is a method to handle this error and if I could have put something in place to see this error but the main point of this topic is even though MongoDB states they have not changed anything, they have.

Now the only solution I can think of to fix this is to recreate the Device Sync App. The new create app seems to have removed the partition and flexible sync options and defaults it to something. I’m not interested in trying to find out as I’m in the process of moving off MongoDB there’s no point in hosting with them without the seamless device sync that was in place.

Hopefully, this will help someone trying to get answers as to why their application is not working without waiting for a response from MongoDB. Also if anyone has more information on this and would like to add please feel free. Also if I’m incorrect on this information, let me know to so that others have a better understanding of whats going on.

[mpobrien (Michael O'Brien)]

@Delphi_Measurement can you share your app ID with us?

[Delphi_Measurement]

@mpobrien

App id: default_admodum_dev-lipjt

[Joseph_Devlin]

Did this ever get resolved for you?

[Delphi_Measurement]

@Joseph_Devlin Here is their response.

They have emailed me the issue.

This is what they said:

On checking internally, we got to know that your translator has failed for 1.5 years and you have not had a client connect in some time, that is why the feature flag to continue showing the sync page did not get added to this application.

Your app should be restored to its normal state now. Please let me know if you have any further concerns, I will be happy to help you.

MongoDB Team

The device sync app hasn’t been working for 1.5 years. This could be true! Just a quick overview of my application when logging into your account you had to pull through default information to your organisation and then sync that default data with the organisation data. this only happens in a new organisation. around 1 year ago we implemented a different method to create these new organisations by automatically populating the organisation’s data with the default data so this method could be removed. The code however still triggered the DownloadAndSync() function.

I am still confused as to why my application was still able to work until the deprecation notice was announced and then only for it to fail if it has failed for 1.5 years.

I do acknowledge that we should have removed the DeviceAndSync() function once we implemented the new method, however, if the translator had failed surely my application would have stopped working 1.5 years ago which would have allowed us to find out sooner.

Another thing I’m slightly disappointed in Mongo for is the lack of alerts regarding this. surely there should be some error notifications that can alert me or anyone else if the “translator” fails. This will allow teams to get onto the issue immediately and not have to wait 1.5 years for their application to stop working and then spend hours sending emails back and forth for a whole week to determine that was the issue.