> "Vadim Mikheev" <vmikheev@sectorbase.com> writes:
> > Anyway, deadlock in my tests are very correlated with new log file
> > creation - something probably is still wrong...
> 
> Well, if you can reproduce it easily, seems like you could 
> get in there and verify or disprove my theory about where
> the deadlock is.

You were right - deadlock disappeared.

BTW, I've got ~320tps with 50 clients inserting (int4, text[1-256])
records into 50 tables (-B 16384, wal_buffers = 256) on Ultra10
with 512Mb RAM, IDE (clients run on the same host as server).

Vadim

Mon, 19 Mar 2001 16:59:57 -0800
"Mikheev, Vadim" <vmikheev@SECTORBASE.COM>
RE: Stuck spins in current 
"Mikheev, Vadim" <vmikheev@SECTORBASE.COM> writes:
>> "Vadim Mikheev" <vmikheev@sectorbase.com> writes:
> Anyway, deadlock in my tests are very correlated with new log file
> creation - something probably is still wrong...
>> 
>> Well, if you can reproduce it easily, seems like you could 
>> get in there and verify or disprove my theory about where
>> the deadlock is.

> You were right - deadlock disappeared.

Okay, good.  I'll bet the correlation to new-log-file was just because
the WAL insert_lck gets held for a longer time than usual if XLogInsert
is forced to call XLogWrite and that in turn is forced to make a new
log file.  Were you running with wal_files = 0?  The problem would
likely not have shown up at all if logfiles were created in advance...

> BTW, I've got ~320tps with 50 clients inserting (int4, text[1-256])
> records into 50 tables (-B 16384, wal_buffers = 256) on Ultra10
> with 512Mb RAM, IDE (clients run on the same host as server).

Not bad.  What were you getting before these recent changes?

			regards, tom lane

Mon, 19 Mar 2001 20:08:38 -0500
Tom Lane <tgl@sss.pgh.pa.us>
Re: Stuck spins in current 
> > BTW, I've got ~320tps with 50 clients inserting (int4, text[1-256])
> > records into 50 tables (-B 16384, wal_buffers = 256) on Ultra10
> > with 512Mb RAM, IDE (clients run on the same host as server).
> 
> Not bad.  What were you getting before these recent changes?

As I already reported - with O_DSYNC this test shows 30% better
performance than with fsync.

(BTW, seems in all my tests I was using -O0 flag...)

Vadim



Wed, 21 Mar 2001 01:46:23 -0800
"Vadim Mikheev" <vmikheev@sectorbase.com>
Re: Stuck spins in current 
> > > BTW, I've got ~320tps with 50 clients inserting (int4, text[1-256])
> > > records into 50 tables (-B 16384, wal_buffers = 256) on Ultra10
> > > with 512Mb RAM, IDE (clients run on the same host as server).
> > 
> > Not bad.  What were you getting before these recent changes?
> 
> As I already reported - with O_DSYNC this test shows 30% better
> performance than with fsync.
> 
> (BTW, seems in all my tests I was using -O0 flag...)

Good data point.  I could never understand why we would ever use the
normal sync if we had a data-only sync option available.  I can imagine
the data-only being the same, but never slower.

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Wed, 21 Mar 2001 08:25:00 -0500 (EST)
Bruce Momjian <pgman@candle.pha.pa.us>
Re: Stuck spins in current