Re: [Tarantool-patches] [tarantool-patches] Re: [PATCH v2 3/4] wal: xrow buffer cursor

[Vladislav Shpilevoy <v.shpilevoy@tarantool.org>]

>>>> +			break;
>>>> +		/* Buffer was discarded. */
>>>
>>> 4. Ok, perhaps now I understand the idea of why do you discard
>>> chunks without any checks if they are in use. Looks cool.
>>>
>>> But it means, that if a relay sends data too slow, it will fall
>>> from the in-memory replication down to disk. Being fallen to a disk,
>>> how can it return back? Isn't it a problem, that the chunks will
>>> be being written to wal so many and fast, that the relay will never
>>> return back to in-memory replication?
>> If it is a temporary slowdown and a relay will process data faster than a 
>> master writes then the relay will return to in-memory replication. In the 
>> opposite case, if the relay is lower that the master, then the relay will be 
>> discarded because of collected wall file - in this case there is nothing we can 
>> do.
> 
> Have you asked Alexander Tikh. to bench you branch? I think
> we need to test how realistic is the case, when WAL writes much faster
> than replicates, and the replicas just never can keep master's pace.
> Is it correct, that relay doesn't send a next transaction until a
> previous is ACKed?

Any news here?