On Sat, Feb 11, 2023 at 07:06:45AM +0100, Pavel Stehule wrote: > pá 10. 2. 2023 v 23:01 odesílatel Justin Pryzby <pry...@telsasoft.com> napsal: > > On Fri, Feb 10, 2023 at 09:23:11PM +0100, Pavel Stehule wrote: > > > pá 10. 2. 2023 v 21:18 odesílatel Andres Freund <and...@anarazel.de> > > > napsal: > > > > On 2023-02-10 21:09:06 +0100, Pavel Stehule wrote: > > > > > Just a small note - I executed VACUUM ANALYZE on one customer's > > > > > database, > > > > > and I had to cancel it after a few hours, because it had more than > > > > > 20GB RAM > > > > > (almost all physical RAM). > > > > > > > > Just to make sure: You're certain this was an actual memory leak, not > > > > just > > > > vacuum ending up having referenced all of shared_buffers? Unless you > > > > use huge > > > > pages, RSS increases over time, as a process touched more and more > > > > pages in > > > > shared memory. Of course that couldn't explain rising above > > > > shared_buffers + overhead. > > > > > > > > > The memory leak is probably not too big. This database is a little bit > > > > > unusual. This one database has more than 1 800 000 tables. and the > > > > > same > > > > > number of indexes. > > > > > > > > If you have 1.8 million tables in a single database, what you saw might > > > > just > > > > have been the size of the relation and catalog caches. > > > > > > can be > > > > Well, how big was shared_buffers on that instance ? > > 20GB RAM > 20GB swap > 2GB shared buffers
Thanks; so that can't explain using more than 2GB + a bit of overhead. Can you reproduce the problem and figure out which relation was being processed, or if the memory use is growing across relations? pg_stat_progress_analyze/vacuum would be one thing to check. Does VACUUM alone trigger the issue ? What about ANALYZE ? Was parallel vacuum happening (are there more than one index per table) ? Do you have any extended stats objects or non-default stats targets ? What server version is it? What OS? Extensions? Non-btree indexes? BTW I'm interested about this because I have an VM instance running v15 which has been killed more than a couple times in the last 6 months, and I haven't been able to diagnose why. But autovacuum/analyze could explain it. On this one particular instance, we don't have many relations, though... -- Justin
