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

On Sat, Jun 2, 2012 at 12:01 PM, Michael Nolan <htfoot@gmail.com> wrote:
> On 6/2/12, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Robert Haas <robertmhaas@gmail.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?

NTP shouldn't have any problem; it uses UTC underneath.  As does
PostgreSQL, underneath.
--
When confronted by a difficult problem, solve it by reducing it to the
question, "How would the Lone Ranger handle this?"