GRPC keep alive need a nice error message

[samsja]

Context

When the keep alive mechanism is triggered we need to catch the exception and display a nice error message

[Adesoji1]

@samsja what are the steps to reproduce so i can fix this issue?

[samsja]

Hey @Adesoji1 thank your for wanting to contribute !

This issue is actually not that easy to reproduce.

Let me gave u some context. The keep alive mechanism is only triggered when the connection is killed abruptly between the Jina Client and the Jina Gateway (the server). In this case we just raise the raw Exception from the grpc library so the Client just end up displaying a weird message. The goal would be to catch the Exception and to display a nice message.

Now starts the messy part. Simulating the abrupt kill is not easy at all ( At least I don't have a good way to do it). This mainly happened when the Flow is running in the cloud in production env.

My ugly way to make it happened is to have a remote flow somewhere (on a VM on aws for example) to connect to it via my laptopt and to, ... , close my wifi. This simulate the behavior, but it is not easy to iterate.

If you manage to reproduce the ugly error message you will be probably able to fix the message. Otherwise I will try to produce a simplier way of reproducing

[Jackmin801]

Is this the "ugly" error?

<AioRpcError of RPC that terminated with:
        status = StatusCode.UNAVAILABLE
        details = "keepalive watchdog timeout"
        debug_error_string = "{"created":"@1666942824.531216000","description":"Error received from peer ipv4:192.168.100.56:12345","file":"src/core/lib/surface/call.cc","file_line":967,"grpc_message":"keepalive watchdog timeout","grpc_status":14}"

[Jackmin801]

If the port rejects, you get this:

<AioRpcError of RPC that terminated with:
        status = StatusCode.UNAVAILABLE
        details = "failed to connect to all addresses"
        debug_error_string = "{"created":"@1666943053.384556000","description":"Failed to pick subchannel","file":"src/core/ext/filters/client_channel/client_channel.cc","file_line":3261,"referenced_errors":[{"created":"@1666943053.384555000","description":"failed to connect to all addresses","file":"src/core/lib/transport/error_utils.cc","file_line":167,"grpc_status":14}]}"

[samsja]

yes