Memory leak (?)

[ugo-fl]

Currently using this client (3.0.0) within a JAX-RS API and experiencing a memory leak which causes after a certain time the server to crash.

After adding a @PreDestroy method which calls statsd.stop() the curve is smoothed, but still going up :

Without this, it only takes a few hours for our server to freeze.

[vickenty]

Hi @ugo-fl, thank you for raising the issue, we will try to reproduce it.

Since you mention @PreDestroy, are you creating client instances for each web request? If so, having to call .stop() is expected: the client starts background threads, so an explicit call is needed to stop them when the client instance is no longer needed. At the same time, creating and stopping a client instance is relatively expensive, so I would recommend to have only one global instance per application. The client is thread safe and the same instance can be used to send metric from all resources.

[ugo-fl]

Hello @vickenty, thank you for your feedback.

I've just tried with a singletonized version of the client, now no metrics are being sent/received and the memory still goes up.
When the whole API is a singleton then I get the metrics properly, but the memory leak is still present.

I think I'm going to quit using the client for the moment and try to post metrics directly instead.

[ugo-fl]

Wait actually it went up in the first 20 minutes but now after a few hours it seems to have stabilized.
I'll come back at you after some days, but to setup the API as a singleton could be the solution.

[KirilMilanovTide]

Has anyone observed such issues on version 4.2.0 of the statsD client?