On Wed, Jan 15, 2014 at 5:17 AM, Tomas Vondra <t...@fuzzy.cz> wrote: > On 14.1.2014 00:38, Tomas Vondra wrote: > > On 13.1.2014 18:07, Alexander Korotkov wrote: > >> On Sat, Jan 11, 2014 at 6:15 AM, Tomas Vondra <t...@fuzzy.cz > >> <mailto:t...@fuzzy.cz>> wrote: > >> > >> On 8.1.2014 22:58, Alexander Korotkov wrote: > >> > Thanks for reporting. Fixed version is attached. > >> > >> I've tried to rerun the 'archie' benchmark with the current patch, > and > >> once again I got > >> > >> PANIC: could not split GIN page, didn't fit > >> > >> I reran it with '--enable-cassert' and with that I got > >> > >> TRAP: FailedAssertion("!(ginCompareItemPointers(&items[i - 1], > >> &items[i]) < 0)", File: "gindatapage.c", Line: > 149) > >> LOG: server process (PID 5364) was terminated by signal 6: Aborted > >> DETAIL: Failed process was running: INSERT INTO messages ... > >> > >> so the assert in GinDataLeafPageGetUncompressed fails for some > reason. > >> > >> I can easily reproduce it, but my knowledge in this area is rather > >> limited so I'm not entirely sure what to look for. > >> > >> > >> I've fixed this bug and many other bug. Now patch passes test suite that > >> I've used earlier. The results are so: > > > > OK, it seems the bug is gone. However now there's a memory leak > > somewhere. I'm loading pgsql mailing list archives (~600k messages) > > using this script > > > > https://bitbucket.org/tvondra/archie/src/1bbeb920/bin/load.py > > > > And after loading about 1/5 of the data, all the memory gets filled by > > the pgsql backends (loading the data in parallel) and the DB gets killed > > by the OOM killer. > > I've spent a fair amount of time trying to locate the memory leak, but > so far no luck. I'm not sufficiently familiar with the GIN code. > > I can however demonstrate that it's there, and I have rather simple test > case to reproduce it - basically just a CREATE INDEX on a table with ~1M > email message bodies (in a tsvector column). The data is available here > (360MB compressed, 1GB raw): > > http://www.fuzzy.cz/tmp/message-b.data.gz > > Simply create a single-column table, load data and create the index > > CREATE TABLE test ( body_tsvector TSVECTOR ); > COPY test FROM '/tmp/message-b.data'; > CREATE test_idx ON test USING gin test ( body_tsvector ); > > I'm running this on a machine with 8GB of RAM, with these settings > > shared_buffers=1GB > maintenance_work_mem=1GB > > According to top, CREATE INDEX from the current HEAD never consumes more > than ~25% of RAM: > > PID USER PR NI VIRT RES SHR %CPU %MEM COMMAND > 32091 tomas 20 0 2026032 1,817g 1,040g 56,2 23,8 postgres > > which is about right, as (shared_buffers + maintenance_work_mem) is > about 1/4 of RAM. > > With the v5 patch version applied, the CREATE INDEX process eventually > goes crazy and allocates almost all the available memory (but somesimes > finishes, mostly by pure luck). This is what I was able to get from top > > PID USER PR NI VIRT RES SHR S %CPU %MEM COMMAND > 14090 tomas 20 0 7913820 6,962g 955036 D 4,3 91,1 postgres > > while the system was still reasonably responsive. >
Thanks a lot for your help! I believe problem is that each decompressed item pointers array is palloc'd but not freed. I hope to fix it today. ------ With best regards, Alexander Korotkov.
