Hello We plProxy to split our database into partitions. See Kristo's blog's about that at http://kaiv.wordpress.com/.
For replication we use Londiste in SkyTools package. SkyTools contains several more scripts that are useful when buildin large and complex systems running on large number of servers. Asko On 9/9/07, novnov <[EMAIL PROTECTED]> wrote: > > > OK, this has been very informative and I'd like to thank the three of you. > > Asynchronous replication to readonly slaves is something I will look into. > I've never touched posgtres replication; and Scott mentioned that he was > not > familiar with PGCluster, so there must be some other replication system > he's > referencing, maybe Slony-I? > > > Trevor Talbot-2 wrote: > > > > On 9/8/07, novnov <[EMAIL PROTECTED]> wrote: > > > >> But basically, it seems that the answer to one of my questions is that > >> there > >> is currently no way with postgres to spread a single database over > >> multiple > >> servers, ala a loadbalanced apache cluster, where requests are > forwarded > >> to > >> different boxes. > > > > Actually, that's essentially the same thing. Whether it's the front > > end or middleware, something splits the requests apart before they're > > processed. > > > > The asynchronous replication to readonly slaves Scott mentioned > > earlier would be roughly equivalent to having several identical apache > > boxes that have their own local copies of files that you periodically > > rsync/ftp/whatever to them from a single place. Partitioning data > > would be roughly equivalent to having one apache box for images, one > > for ads, etc. > > > > From what I've seen people mention of RAC, it provides strong > > guarantees about server consistency -- all of them have the changes or > > none of them do -- but you need to go to great effort to achieve the > > same thing on a set of apache boxes too. I mean, you don't have each > > box accepting file uploads via the web and assume the others will > > magically see the same file at exactly the same time, right? Unless, > > of course, you're using them purely for CPU reasons and have a single > > shared storage pool. > > > > Whatever is splitting the requests may do it on a "session" level too, > > which makes it easier for the backend clusters. E.g. if a given user > > always hits a given apache box, that file upload situation isn't a > > problem as long as you can rsync faster than the sessions time out. > > Often you need to load balance this way anyway if you have a web app > > using an internal notion of sessions -- session data isn't replicated > > to other apache boxes. (If you need it to be replicated, you're > > already in special design territory, not just easy load balancing.) > > > > It all varies depending on the details of what you're doing. Even > > that seemingly straightforward question isn't specific enough :( > > > > ---------------------------(end of broadcast)--------------------------- > > TIP 6: explain analyze is your friend > > > > > > -- > View this message in context: > http://www.nabble.com/Scalability-Design-Questions-tf4406693.html#a12580273 > Sent from the PostgreSQL - general mailing list archive at Nabble.com. > > > ---------------------------(end of broadcast)--------------------------- > TIP 6: explain analyze is your friend >
