On Sun, 2011-01-02 at 11:11 -0600, Kevin Grittner wrote: > Simon Riggs wrote: > > > Do you agree that requiring response from 2 sync standbys, or > > locking up, gives us 94% server availability, but 99.9992% data > > durability? > > I'm not sure how to answer that. The calculations so far have been > based around up-time and the probabilities that you have a machine up > at any moment and whether you can have confidence that if you do, you > have all committed transactions represented. There's been an implied > assumption that the down time is unplanned, but not much else. The > above question seems to me to get into too many implied assumptions > to feel safe throwing out a number without pinning those down a whole > lot better. If, for example, that 2% downtime always means the > machine irretrievably went up in smoke, hitting unavailable means > things are unrecoverable. That's probably not the best assumption > (at least outside of a combat zone), but what is?
Not really relevant. There's no room at all for downtime of any kind in a situation where all servers must be available. -- 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
