GRPC keepalive server side not working

[unludo]

GRPC keepalive server side not working

[qiwzhang]

ESP downstream and upstream are using different connections. There is not one to one connection mapping between these two, it only has stream to stream mapping. upstream is using grpc channel, many downstream connections may use one grpc channel. So mapping keep alive between downstream and upstream is difficult.

[unludo]

@qiwzhang Thank you for your answer. I don't understand though as each stream is specific to each client - server connection. There is no 'broadcast'.

I was wondering, is it possible to have a grpc client to communicate with a grpc server through a L4 LB without an ESP?
ESP is doing grpc proxy or more ?
I tried to not use an ESP but was not able to have Client -> L4 LB -> Server (inside GKE) working, whereas with Client -> L4 LB -> ESP + server it works. Is it normal for you?

[qiwzhang]

In theory, L4LB should work for gRPC protocol.
It may have something to do with your GKE LB or Ingress that doesn't support Http2. ESP can convert http1 to http2. But I believe GKE LB or Ingress does support http2, you may have configured it wrong.

[unludo]

Actually I use L4 LB which is tcp. I have no ingress.

…

________________________________ From: Wayne Zhang <[email protected]> Sent: Thursday, August 20, 2020 7:58:33 PM To: cloudendpoints/esp <[email protected]> Cc: unludo <[email protected]>; Author <[email protected]> Subject: Re: [cloudendpoints/esp] GRPC keepalive server side not working (#812) In theory, L4LB should work for gRPC protocol. It may have something to do with your GKE LB or Ingress that doesn't support Http2. ESP can convert http1 to http2. But I believe GKE LB or Ingress does support http2, you may have configured it wrong. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub<#812 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AAP7P4PLIR5KPD2BTFNQWKTSBVP4TANCNFSM4QDTWG2Q>.

[qiwzhang]

Somewhere in the path-path, grpc request is downgraded from http2 to http1, and ESP upgrades back to http2. That is how ESP has helped.