Allow infinite pings

[tamirOK]

Hi!

I want my client to hold open connection to server infinitely long by doing pings. To do so, I have to provide correct values for Configuration object. Can you answer my questions please:

• What is a difference between _keepalive_time and http2_min_sent_ping_interval_without_data settings? I have checked Connection._ping method and these options look very similar to me.
• How can I remove limit on max number of sent pings?
• Can I allow ping function to run forever?

Thanks!

[tamirOK]

I have read the definitions of the options here and I think there are couple of problems in the implementation:

• Connection is always closed after _keepalive_timeout seconds, but it should close only when it didn't received an acknowledgement.
• GRPC_ARG_HTTP2_MAX_PINGS_WITHOUT_DATA is allowed to be 0. However, I am receiving:
  ValueError: "_http2_max_pings_without_data" should be positive
• _http2_min_sent_ping_interval_without_data should not affect client side.

[vmagamedov]

Connection is always closed after _keepalive_timeout seconds, but it should close only when it didn't received an acknowledgement.

– _keepalive_timeout is cancelled when we receive PING acknowledgment.

GRPC_ARG_HTTP2_MAX_PINGS_WITHOUT_DATA is allowed to be 0

– fixed

_http2_min_sent_ping_interval_without_data should not affect client side.

– please elaborate

[vmagamedov]

Please take in mind that non-default keep-alive settings can cause PING strikes as described in https://github.com/grpc/grpc/blob/master/doc/keepalive.md, currently this will cause a cancellation of all in-flight requests (h2 library doesn't handle GOAWAY frame correctly).

[vmagamedov]

This issue was closed unintentionally, please reopen it if current keep-alive implementation still doesn't conforms to the reference documentation.

[tamirOK]

Can I control GRPC_ARG_HTTP2_MAX_PING_STRIKES and GRPC_ARG_HTTP2_MIN_RECV_PING_INTERVAL_WITHOUT_DATA_MS for the server? If not, are these values equals to the default values from doc?

[vmagamedov]

grpclib currently doesn't implements strikes functionality, so it is important only if you're using grpcio and other official gRPC implementations on the server-side.