Re: XMin Hot Standby Feedback patch

Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>

From: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
To: Simon Riggs <simon@2ndQuadrant.com>
Cc: Daniel Farina <daniel@heroku.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2011-02-15T16:49:48Z
Lists: pgsql-hackers
On 15.02.2011 18:42, Simon Riggs wrote:
> On Sat, 2011-02-12 at 14:11 -0800, Daniel Farina wrote:
>> This is another bit of the syncrep patch split out.
>>
>> I will revisit the replication timeout one Real Soon, I promise -- but
>> I have a couple things to do today that may delay that until the
>> evening.
>>
>> https://github.com/fdr/postgres/commit/ad3ce9ac62f0e128d7d1fd20d47184f867056af1
>>
>> Context diff supplied here.
>
> Greg just tipped me off to this thread a few hours ago. I saw your other
> work on timeouts which looks good.
>
> I've reworked this feature myself, and its roughly the same thing you
> have posted, so I will just add on to this thread. The major change from
> my earlier patch is that the logic around setting xmin on the master is
> considerably tighter, and correctly uses locking.

It would be wise to also transmit the epoch in addition to xmin, to 
avoid confusion if the standby is > 2 billion transactions behind.

-- 
   Heikki Linnakangas
   EnterpriseDB   http://www.enterprisedb.com