Backpressure

[bsideup]

Hi!

Are there any well-known backpressure issues? I get backpressure-related exceptions in my app (based on Reactor) and I have a feeling that they come from reactive-grpc.

I know that there is no "request demand" notion in gRPC and you have to deal with readiness, this is why I expect issues with backpressure by nature.

[rmichela]

Can you be more specific about the backpressure-related exceptions you are getting?

@cbornet Perhaps you can help?

[bsideup]

@rmichela Reactor gives me OverflowException

Don't get me wrong, I'm still not sure whom to blame, just wanted to re-check, maybe there are some known issues with backpressure in reactive-grpc

[rmichela]

I'm not going to say there isn't an issue in reactive-grpc. 😁 It passes the TCK, but the gRPC and Reactive backpressure models are subtly different and there may still be an impedance mismatch in the code.

What's the stack trace of your OverflowException?

[bsideup]

@rmichela I'm running different tests right now to figure out where the problem is.

Too many moving parts (my code, gRPC, reactive-gRPC, gRPC-netty/Armeria, client, client's code), I'll try to narrow it first :)

[rmichela]

Thanks! Keep me posted.

Even if the problem isn't in RxGrpc itself, your findings will make for good documentation. 😉

[rmichela]

@bsideup Any update?

[bsideup]

Hi @rmichela,

So far so good :) We had an issue with Armeria, but when we reverted it to gRPC-netty + reactive-grpc everything became stable 👍