Prepared transactions that are sitting still do the same thing, and show no connections.
On Fri, Jul 12, 2013 at 2:25 PM, Scott Marlowe <scott.marl...@gmail.com>wrote: > Idle in Transaction? Or plain Idle? Idle in Transaction stops vacuum from > reclaiming space and is indicative of a broken application. > > > On Fri, Jul 12, 2013 at 9:39 AM, Bradley McCune > <bradley.mcc...@noaa.gov>wrote: > >> The only transactions present were "<IDLE>" for current_query. I even >> stopped the remote services, restarted the PostgreSQL server (assumingly, >> there should be no transactions occurring now), and performed another >> VACUUM FULL followed by REINDEX due to known fullvac index bloat in pre-9 >> pgsql version. >> >> >> On Fri, Jul 12, 2013 at 11:28 AM, Scott Marlowe >> <scott.marl...@gmail.com>wrote: >> >>> Did you have a long running trasnaction? Especially a prepared >>> transaction, blocking the vacuum from reclaiming the space? >>> >>> On Fri, Jul 12, 2013 at 8:10 AM, Bradley McCune <bradley.mcc...@noaa.gov> >>> wrote: >>> > David, >>> > >>> > (As a preface, I have already gone forward with completely rebuilding >>> the >>> > database which seems to have finally fixed the problem. Rebuilding the >>> > table itself had no effect, and I couldn't wait much longer to move >>> > forward.) >>> > >>> > Yes, this seems similar, however, the key difference being that VACUUM >>> FULL >>> > did not alleviate the problem. The extra "bloated" disk space was >>> still >>> > considered "in use" by the data server, and so it was never returned >>> to the >>> > system. I have a suspicion that the server was storing the table data >>> in >>> > pages in an inefficient manner (by unknown means) because we had >>> roughly ~5x >>> > the number of pages used on that TOAST table to store the same number >>> of >>> > tuples compared to other similar databases. >>> > >>> > Depending on how often you have to use VACUUM FULL, you might want to >>> > consider tweaking the autovacuum to be more aggressive on that hot >>> table to >>> > keep it in check more often. (Recycling the disk space more >>> efficiently >>> > rather than sending it back to the server only to be reallocated to the >>> > database again.) >>> > >>> > >>> > On Fri, Jul 12, 2013 at 4:09 AM, David Welton <dav...@dedasys.com> >>> wrote: >>> >> >>> >> Hi, >>> >> >>> >> I have a very similar problem... details below. >>> >> >>> >> On Wed, Jul 3, 2013 at 5:19 PM, Paul Tilles <paul.til...@noaa.gov> >>> wrote: >>> >> > Recently, I've had a PostgreSQL 8.2.11 server upgraded to 8.4 in >>> order >>> >> > to >>> >> > take advantage of autovacuum features. This server exists in a very >>> >> > closed >>> >> > environment (isolated network, limited root privileges; this >>> explains >>> >> > the >>> >> > older software in use) and runs on RHEL5.5 (i686). After the >>> upgrade, >>> >> > the >>> >> > database has constantly been growing to the tune of 5-6 GB a day. >>> >> > Normally, >>> >> > the database, as a whole, is ~20GB; currently, it is ~89GB. We have >>> a >>> >> > couple >>> >> > other servers which run equivalent databases and actually >>> synchronize >>> >> > the >>> >> > records to each other via a 3rd party application (one I do not have >>> >> > access >>> >> > to the inner workings). The other databases are ~20GB as they >>> should be. >>> >> >>> >> Our machine is an Ubuntu 12.04 system running on AWS, so it's a 64 bit >>> >> system: >>> >> >>> >> PostgreSQL 9.1.9 on x86_64-unknown-linux-gnu, compiled by gcc >>> >> (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3, 64-bit >>> >> >>> >> > Running the following SQL, it's fairly obvious there's an issue >>> with a >>> >> > particular table, and, more specifically, its TOAST table. >>> >> >>> >> Same thing here: we have a table with around 2-3 megs of data that is >>> >> blowing up to *10 gigs*. >>> >> >>> >> > This TOAST table is for a table called "timeseries" which saves >>> large >>> >> > records of blobbed data. ASUM(LENGTH(blob)/1024./1024.) of all the >>> >> > records >>> >> > in timeseries yields ~16GB for that column. There should be [b]no >>> >> > reason[/b] >>> >> > this table's TOAST table should be as large as it is. >>> >> >>> >> Similar situation: it's a bytea column that gets "a lot" of updates; >>> >> in the order of 10's of thousands a day. >>> >> >>> >> > I've performed a VACUUM FULL VERBOSE ANALYZE timeseries, and the >>> vacuum >>> >> > runs >>> >> > to completion with no errors. >>> >> >>> >> VACUUM FULL fixes the problem for us by recouping all the wasted disk >>> >> space. I don't have the knowledge to investigate much further on my >>> >> own, but I'd be happy to try out a few things. The database is, >>> >> unfortunately, sensitive data that I can't share, but I could probably >>> >> script a similar situation... >>> >> >>> >> -- >>> >> David N. Welton >>> >> >>> >> http://www.dedasys.com/ >>> > >>> > >>> > >>> > >>> > -- >>> > Bradley D. J. McCune >>> >>> >>> >>> -- >>> To understand recursion, one must first understand recursion. >>> >> >> >> >> -- >> Bradley D. J. McCune >> NOAA/OCWWS/HSD >> Community Hydrologic Prediction System - Support >> CHPS FogBugz Administrator >> Office phone: (301) 713-1625 x160 >> >> >> > > > -- > To understand recursion, one must first understand recursion. > -- To understand recursion, one must first understand recursion.
