watch grpc stream stays open after the last watcher is canceled

[yehiyam]

Following my conclusion from #61 I saw that when the last watch is canceled, the gRPC stream on the client side is closed, and a new one is created when a new watch is requested.
Looking at the etcd prometheus metric etcd_debugging_mvcc_watch_stream_total, the watch stream in the server is not closed, and the count is increasing until the client process exit.
This leads to resource leak in the server.

[yehiyam]

@connor4312 Anything progress on this?

[godu]

etcd-io/etcd#9391

[godu]

I try to replace all this.getStream().end(); by this.getStream().cancel();.
https://github.com/mixer/etcd3/blob/master/src/watch.ts
It's not a graceful close, but i think we need to provide an extra method to force to cancel connection.

[monkbroc]

I'm going to use @godu fork until this issue is resolved in upstream.
https://www.npmjs.com/package/@coorpacademy/etcd3
CoorpAcademy@1905266

[connor4312]

Thanks for raising the issue. Unfortunately it's hard to write a test for this, but I made the changes which'll land in v0.2.10 soon.