Skip site navigation (1) Skip section navigation (2)

Re: Core team statement on replication in PostgreSQL

From: Josh Berkus <josh(at)agliodbs(dot)com>
To: Bruce Momjian <bruce(at)momjian(dot)us>
Cc: Marko Kreen <markokr(at)gmail(dot)com>, David Fetter <david(at)fetter(dot)org>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: Core team statement on replication in PostgreSQL
Date: 2008-05-29 16:18:44
Message-ID: 483ED764.7050804@agliodbs.com (view raw or flat)
Thread:
Lists: pgsql-advocacypgsql-hackers
Bruce,

> Another idea I discussed with Tom is having the slave _delay_ applying
> WAL files until all slave snapshots are ready.
> 

Well, again, that only works for async mode.  I personally think that's 
the correct solution for async.  But for synch mode, I think we need to 
push the xids back to the master; generally if a user is running in 
synch mode they're concerned about failover time and zero data loss, so 
holding back the WAL files doesn't make sense.

Also, if you did delay applying WAL files on an async slave, you'd reach 
a point (perhaps after a 6-hour query) where it'd actually be cheaper to 
rebuild the slave than to apply the pent-up WAL files.

--Josh Berkus


In response to

Responses

pgsql-hackers by date

Next:From: Andrew DunstanDate: 2008-05-29 16:19:48
Subject: Re: Core team statement on replication in PostgreSQL
Previous:From: Aidan Van DykDate: 2008-05-29 16:16:15
Subject: Re: Core team statement on replication in PostgreSQL

pgsql-advocacy by date

Next:From: Andrew DunstanDate: 2008-05-29 16:19:48
Subject: Re: Core team statement on replication in PostgreSQL
Previous:From: Aidan Van DykDate: 2008-05-29 16:16:15
Subject: Re: Core team statement on replication in PostgreSQL

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group