Memory leak issue

[lijunle]

Describe the bug

It is hard to describe or repro the bug. I rerun this Trello in an Azure function every 5 minutes. From the telemetry, it spend longer and longer time to send the requests. My guess is, there is some memory leak issue in the code. Do you have any ideas?

Screenshots

Vertical axis is the time to send the request.

Desktop (please complete the following information):

• OS: Linux
• .Net Target: .Net core 2.2
• Version [e.g. 22]

Additional context

I tried to call TrelloConfiguration.Cache.Clear() after each call but it does not help.

[gregsdennis]

Thanks for reporting this. Do you modify TrelloConfiguration at all, or are you using the default settings.

Also, can you let me know what package version you're using, please?

[lijunle]

No modification on TrelloConfiguration class.

Version 3.8.1.

[lijunle]

The source code is here: https://gist.github.com/lijunle/eafa8cb87f651b2dd904c8352ed5e6c6

It is quite short.

[gregsdennis]

Thanks. I'll have a look tonight.

[gregsdennis]

So it looks like there may be a memory leak, but I don't think that's the primary issue. The EventAggregator holds on to everything that subscribes using weak references until it discovers (through an event publish) that it doesn't exist.

However, with each subscriber, it must check to see if that object hasn't already subscribed, and just about every object subscribes. As the number of subscribers increases, this check takes more and more time. This is the source of the increasing delay.

I'll be publishing v3.10.1 soon, which completely disables the EventAggregator when consistency processing is disabled (which appears to be your case).

[lijunle]

@gdziadkiewicz From monitor, the issue is resolved! Thanks a lot for the quick help!

[lijunle]

Hmm... The request time is stable, however, there is still some kinds of memory leak.

[lijunle]

It shows the BoardContext is never released. I took a quick look at the code. This line of code is strange. The Synchronized handler is never released.

https://github.com/gregsdennis/Manatee.Trello/blob/1b40470dfb1c9b6abe79b740a2a601cec37d885f/Manatee.Trello/Board.cs#L379

This seems a general issue on all context classes.

https://github.com/gregsdennis/Manatee.Trello/blob/ad33fa0a6bac4ad9fc629634ca39fdd3175bf3c7/Manatee.Trello/Card.cs#L429

[lijunle]

@gregsdennis Why the Synchronized is declared as an event? It sounds should be a weak reference callback on the constructor.

https://github.com/gregsdennis/Manatee.Trello/blob/cce81cbab2688f4f7a1a2a6a47f5b408d81f4f75/Manatee.Trello/Internal/Synchronization/SynchronizationContext.cs#L26