[Drbd-dev] Protocol C

raulhp raulhp at ugr.es
Wed May 28 12:14:30 CEST 2014

Hi Lars,

I´m trying to understand how ACK´s works en Protocol C to try to use it 
in Reliable Multicast in each receiver, I´m using a Reliable Multicast 
with NACK (Negative-ACKnowledgment) only in each loss packet.


El 2014-05-28 00:40, Lars Ellenberg escribió:
> On Tue, May 27, 2014 at 05:33:53PM +0200, raulhp wrote:
>> Hi all,
>> Can someone explain me how the Protocol C operate?, if the receiver
>> send an ACK for every block or how ACK works.
> It basically goes like this:
> local:
>   submit to disk
> + send the data,
> 			remote: receive the data
> disk completion			submit to disk
> 				disk completion
> 				send ack back
> receive ack
> complete to upper layers,
> once both local disk completion
> and remote ack have been seen.
> With some more housekeeping to be able to detect failures,
> and recover from them as gracefully as possible.
>> which exactly is the source code?
> exactly "most of it" ;-) sorry.
> there is a lot going on, and all those various stages cannot be 
> covered
> with "look there, these six lines of code do it".
> What are you trying to do?

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