Re: Vacuum Problems

Maybe Could be Check-Points? I have changed the parameters sometime ago.
Follow:
effective_cache_size = 200MB

checkpoint_segments = 40 # in logfile segments, min 1, 16MB
each
checkpoint_timeout = 3min # range 30s-1h

#bgwriter_delay = 200ms # 10-10000ms between rounds
bgwriter_lru_percent = 16.0 # 0-100% of LRU buffers
scanned/round
bgwriter_lru_maxpages = 170 # 0-1000 buffers max written/round
bgwriter_all_percent = 7.0 # 0-100% of all buffers
scanned/round
bgwriter_all_maxpages = 400 # 0-1000 buffers max written/round

Now I'm having the following problem on vacuum:
vacuumdb: vacuuming of database "Postgres" failed: ERRO: multiple active
vacuums for index "PartInd_replicacao_historico_sl_log_2-node-1".

But there's no anymore vacuum running.

2008/12/8 Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com>

> On Mon, Dec 8, 2008 at 10:17 AM, Rafael Domiciano
> <rafael(dot)domiciano(at)gmail(dot)com> wrote:
> > Here's the output. While the process was running my database get sometime
> > without doing anything.
> > You said that I probably get low numbers, but what numbers?
>
> We're looking for MB/s and the bi/bo fields in bmstat (blocks in / blocks
> out)
>
> > [root(at)postgres banco]# time dd if=/dev/zero of=/banco/testfile
> bs=1000000
> > count=500
> > 500+0 records in
> > 500+0 records out
> > 500000000 bytes (500 MB) copied, 85,4485 seconds, 5,9 MB/s
> > real 1m25.451s
> > user 0m0.003s
> > sys 0m1.617s
> > [root(at)postgres banco]# time dd of=/dev/null if=/banco/testfile
> > 976562+1 records in
> > 976562+1 records out
> > 500000000 bytes (500 MB) copied, 47,5025 seconds, 10,5 MB/s
> > real 0m47.543s
> > user 0m0.457s
> > sys 0m1.470s
> > And the vmstat output:
> >
> > procs -----------memory---------- ---swap-- -----io---- --system--
> > -----cpu------
> > r b swpd free buff cache si so bi bo in cs us sy
> id
> > wa st
> > 0 8 111760 56432 19812 1305692 0 0 744 832 2488 1518 5 3
> 46
> > 46 0
>
> Here, the bi/bo numbers are 768 in and 832 out. That's k/second we're
> looking at.
>
> Lots of the same numbers cut out.
>
> > procs -----------memory---------- ---swap-- -----io---- --system--
> > -----cpu------
> > r b swpd free buff cache si so bi bo in cs us sy
> id
> > wa st
> > 0 6 111760 55452 18528 1296412 0 0 88 25040 1843 1436 2 3
> 34
> > 61 0
> > 1 7 111760 52352 18540 1296472 0 0 36 15220 1467 944 3 2
> 27
> > 68 0
> > 0 6 111760 54152 18552 1296568 0 0 88 42296 1609 822 1 2
> 38
> > 59 0
> > 1 8 111760 52412 18580 1296752 0 0 172 27052 1567 950 2 3
> 27
> > 69 0
> > 0 6 111724 53904 18632 1297008 320 0 580 1504 1902 2320 5 6
> 23
> > 66 0
> > 1 6 111724 54280 18660 1297200 4 0 200 1060 2014 1783 5 3
> 44
> > 48 0
> > 1 7 111676 51388 16340 1302348 8 0 156 1212 1684 848 2 2
> 53
> > 42 0
> > 1 6 111668 55040 14864 1301048 0 4 152 46328 1595 5108 1 5
> 40
> > 54 0
>
> Now we're showing that we can write to the disk at 25 to 42 Megs a
> second, not too bad. But it looks really bursty, like it can sustain
> this throughput for only a few seconds. Try writing a larger file
> and run vmstat 10 or 60 as well and see what the average over a longer
> time with a larger file is. I get a feeling your machine has a hard
> time sustaining throughput for some reason.
>