chore: support keepalive and deadline configuration for grpc sink

[mayankrai09]

Hey, I just made a Pull Request!

Adding capabilities to set deadlines, keepalive_time, and keepalive_timeout for grpc sink.

keepalive_time and keepalive_timeout helps early identify half-open connection.
Linux by default has a mechanism to detect less-clean failure (half-open connection) with net.ipv4.tcp_retries2. This has a default value of 15. Only when that number is reached, the OS will forcefully terminate the “half-open” connection and force the connection to be recreated.

Deadlines allow gRPC clients to specify how long they are willing to wait for an RPC to complete before the RPC is terminated with the error DEADLINE_EXCEEDED. If you don’t set a deadline, resources will be held for all in-flight requests, and all requests can potentially reach the maximum timeout. Which would increase the latency of the service.

[lavkesh]

    protected CallOptions decorateCallOptions() {
        CallOptions defaultCallOption = CallOptions.DEFAULT;
        if (grpcSinkConfig.getSinkGrpcArgDeadlineMS() != null && grpcSinkConfig.getSinkGrpcArgDeadlineMS() > 0) {
            return defaultCallOption.withDeadlineAfter(grpcSinkConfig.getSinkGrpcArgDeadlineMS(), TimeUnit.MILLISECONDS);
        }
        return defaultCallOption;
    }

[lavkesh]

This needs to be checked.. let's think about a default value.

[mayankrai09]

Default grpc client don't set any default value. Not sure what would be right default value for us. I would prefer not to have any default value for deadline.

[mayankrai09]

@lavkesh - Can we merge this PR?