atsaloli.t...@gmail.com (Aleksey Tsalolikhin) writes: > Situation: Disk usage on production server root filesystem is at 68% > utilization (80 GB used), on DR is at 51% (56 GB used). We use > SlonyII-1.2.x to keep the DR up to date. I would like to account for > the 24 GB difference.
It's more than likely a result of transactions failing on the origin, leaving dead space around, where replication doesn't bother trying to do any work for the "failed stuff," with the consequence that there's no corresponding "clutter" on the replica. I'm talking here about cases of failures that are expected. Look to what activities you have that tend to lead to tranactions that ROLLBACK. Slony-I makes no attempt to replicate activity that is terminated by ROLLBACK (explicit or implicit), so all that activity won't be processed on replicas. For instance, in our applications, operating domain registries, intentionally failed database transactions occur heavily *common* whenever customers are 'fighting' over domain names - one and only one customer can win the name, while all others lose, and each losing request leaves a certain amount of mess in its wake. Common patterns of this sort include transactions that fail because: - Customer has insufficient funds on account to pay for the transaction - Inventory request fails because there are insufficient items in stock - Attempt to insert a second instance of an object that is required to be unique - Rejection of partially processed transaction due to violation of some business policy (which is mighty open-ended!) It's likely, as well, that there is some set of tables that you are not vacuuming heavily enough. Probably a table or three needs to have CLUSTER run on it to bring them down to size, and you may need to fiddle with autovacuum parameters to vacuum more frequently. -- (reverse (concatenate 'string "moc.liamg" "@" "enworbbc")) http://linuxdatabases.info/info/lisp.html "Microsoft has world class quality control" -- Arthur Norman -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
