[Tarantool-patches] [PATCH v8 2/2] relay: provide information about downstream lag

[Cyrill Gorcunov]

On Thu, Jun 17, 2021 at 12:01:32PM +0300, Serge Petrenko wrote:
> I think I understand what you mean now. But still, this description is
> confusing.
> 
> When you're saying it's "time delta when data is already written to a
> replica's WAL" it sounds like the delta is taken on replica, not on master.
> And that's not true.
> It's also unclear from this description that packet travel time (ack from
> replica to master) is included into downstream.lag
> 
> So I would reformulate the description to something like
> 
> "Downstream.lag is the lag between the main node writes a certain
> transaction to it's own WAL and the moment it receives an ack for
> this transaction from a replica".

Thanks, Serge! I'll update the description.