Re: Re: [COMMITTERS] pgsql: Send new protocol keepalive messages to standby servers.

On 6/2/12, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> On the other hand, if we simply say "PostgreSQL computes the
>> replication delay by subtracting the time at which the WAL was
>> generated, as recorded on the master, from the time at which it is
>> replayed by the slave" then, hey, we still have a wart, but it's
>> pretty clear what the wart is and how to fix it, and we can easily
>> document that. Again, if we could get rid of the failure modes and
>> make this really water-tight, I think I'd be in favor of that, but it
>> seems to me that we are in the process of expending a lot of energy
>> and an even larger amount of calendar time to create a system that
>> will misbehave in numerous subtle ways instead of one straightforward
>> one. I don't see that as a good trade.
>
> Well, okay, but let's document "if you use this feature, it's incumbent
> on you to make sure the master and slave clocks are synced. We
> recommend running NTP." or words to that effect.

What if the two servers are in different time zones?
--
Mike Nolan