nsqd: Empty Queue should reset the InFlight count of consumers

[dmarkham]

This will keep them insync after they try and fail to FIN messages
that were InFlight when the Queue was Emptied.

[dmarkham]

This is a proposed fix for what I think is a issue with channel.clients staying in sync with a channel after Empty was called. If a channel is actively getting consumed and you empty the Queue the channel.clients can get hung with their In-Flight number above the ready count.

[mreiferson]

Looks like you're onto something here. Will poke around today.

Thanks @dmarkham

[mreiferson]

So the fix itself looks good, the only issue I've been mulling over is the name of the method on the client.

I'm leaning towards s/SetReadyCount/Empty (without a parameter) so that the knowledge of what to do when an Empty action occurs is kept on the side of the client code rather than the channel code. This way the code reads as if you're propagating this event to each client rather than updating the clients internal state directly.

Does that make sense? Thoughts?

[dmarkham]

the SetInFlightCount was based on SetReadyCount I'm happy to rename it to EmptyFlightCount or ResetFlightCount with no args to look more like a notification to the Client.

[dmarkham]

your thinking just Empty, Ok after rereading your post I understand and like it. I'll get the patch ready ASAP.

[mreiferson]

cool, looks great, thanks for identifying and fixing this.