On Sun, 2011-01-02 at 18:54 +0200, Heikki Linnakangas wrote: > I believe we all agree that there's different use cases that require > different setups. Both "first-past-the-post" and "wait-for-all-to-ack" > have their uses.
Robert's analysis is that "first-past-the-post" doesn't actually improve the durability guarantee (according to his calcs). Which means that 1 primary, 2 sync standbys with first-past-the-post is actually worse than 1 primary, 1 sync and 1 async standby in terms of its durability guarantees. So ISTM that Robert does not agree that both have their uses. > I'm not > sure what the point of such a timeout in general is, but people have > requested that. Again, this sounds like you think a timeout has no measurable benefit, other than to please some people's perceived needs. > The "wait-for-all-to-ack" looks a lot less ridiculous if you also > configure a timeout and don't wait for disconnected standbys Does it? Do Robert, Stefan and Aidan agree? What are the availability and durability percentages if we do that? Based on those, we may decide to do that instead. But I'd like to see some analysis of your ideas, not just a "we could". Since nobody has commented on my analysis, lets see someone else's. > There's no point in arguing over which is better. I'm trying to compare quantifiable benefit of various options to see what goes into Postgres. I don't want to put anything in that we cannot all agree has a measurable benefit to someone (that has the appropriate preference). -- Simon Riggs http://www.2ndQuadrant.com/books/ PostgreSQL Development, 24x7 Support, Training and Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
