In the last exciting episode, Leonardo.Francalanci@xxxxxxxxxxxxx (Leonardo Francalanci) wrote: > In other words: how can asynchronous replication be used in an > application??? Yes, this is an issue. Asynchronous replication is NOT suitable in cases where you point applications that need forcibly up-to-date information to a replica that is (even just a little) behind. We *have to* point all of the applications that need up-to-the-instance balance information to the "master" system. But there are doubtless plenty of places where you could use data that isn't *forcibly* up to date. - For instance, running temporal reports against a replica should turn out fine. - We run the WHOIS service against replicas; we don't promise instantaneous propagation, and nobody worries too much if they get information that, in a few cases, is a few seconds out of date. - In a web sales system, I'd be inclined to run "normal" queries against a replica for the portion of the workflow that involves users assembling their "basket" of products. And move to pointing to the "master" when it comes time to "check out" the order, so that the final order gets the most up-to-date data. Asynchronous replication isn't good for *everything*, but you'll generally find ways to use replicas, when you have them... -- let name="cbbrowne" and tld="ntlug.org" in String.concat "@" [name;tld];; http://linuxfinances.info/info/lsf.html "The best design is not predicated on how brain-dead you can be and still operate it." -- David C. Wright
