Reuse TCP connection / keep-alive

[muety]

I might be totally wrong, but to me it seems like Wakatime does not reuse an existing TCP connection in consecutive requests. Take a look at this Wireshark screenshot.

What you can see is three consecutive requests (I changed tabs in VSCode three times) and apparently, new TCP- and TLS handshakes are performed each time.

Please correct me if I got something wrong. But if not, wouldn't it be worth to reuse the connection for efficiency?

[muety]

I figured out the problem. The cli is using requests.Session, which is generally good. Sessions are made to (1) keep request parameters among multiple requests and (2) to keep the underlying TCP connection alive for consecutive requests. SessionCache serializes Session objects to SQLite and reads them back for every request that is made. This is useful to keep internal attributes of the session class. However, as a new object is instantiated every time, the TCP connection is closed once the old session runs out of scope.

I'd like to fix this by extending the SessionCache cache to hold a reference to the current open session in memory and change the api module to hold a SessionManager "singleton" instead of instantiating a new one for every request.

Are you open for PRs, @alanhamlett ?

[alanhamlett]

hold a SessionManager "singleton" instead of instantiating a new one for every request

Would that singleton be shared across multiple Python processes?

[alanhamlett]

Are you open for PRs?

Yes, for sure. However we're also working on porting this Python code into Go so it might be better worth the time to fix it in the new repo: https://github.com/wakatime/wakatime-cli

[muety]

Would that singleton be shared across multiple Python processes?

That's a good point. If I think about it, my above mentioned approach would only help to reuse the connection across multiple calls to send_heartbeats() within the same process, i.e. when sending multiple batches of old heartbeats. It's probably not worth the effort then.

we're also working on porting this Python code into Go

Very cool! I assume the new version is going to be a cli as well? An alternative would be to have a long-running daemon process that listens on local TCP/IP connections or so. But that would require to adapt all plugins and probably comes with some disadvantages on its own.

[muety]

What has happened to wakatime/wakatime-cli ? 🤔

[gandarezwarren]

What has happened to wakatime/wakatime-cli ? 🤔

It's private now because we're not ready and still redesign the entire cli. Will reopen as soon as possible.