From: Tomas Vondra <tv@fuzzy.cz>
To: pgsql-performance@postgresql.org
Subject: Re: Slow queries / commits, mis-configuration or hardware issues?
Date: Wed, 16 Nov 2011 02:16:53 +0100
Message-ID: <4EC30F05.6010901@fuzzy.cz> (raw)
In-Reply-To: <CAPVp=ga6CkO8vXJJs5PswKv0Cf3R3SpUK+KmQXY8edpc84CddA@mail.gmail.com>
References: <CAPVp=gYs7uYF_hy0MDBkpRCxNbWQHPSyP6sXO-6SJZ_TvaU=XQ@mail.gmail.com>
<87e450fd65045c328f41e1b99a4029d5.squirrel@sq.gransy.com>
<CAPVp=ga6CkO8vXJJs5PswKv0Cf3R3SpUK+KmQXY8edpc84CddA@mail.gmail.com>
Dne 14.11.2011 22:58, Cody Caughlan napsal(a):
> I ran bonnie++ on a slave node, doing active streaming replication but
> otherwise idle:
> http://batch-files-test.s3.amazonaws.com/sql03.prod.html
>
> bonnie++ on the master node:
> http://batch-files-test.s3.amazonaws.com/sql01.prod.html
>
> If I am reading this right, this is my first time using it, the
> numbers dont look too good.
I've done some benchmarks on my own (m1.xlarge instance), and the
results are these (http://pastebin.com/T1LXHru0):
single drive
------------
dd writes: 62 MB/s
dd reads: 110 MB/s
bonnie seq. writes: 55 MB/s
bonnie seq. rewrite: 33 MB/s
bonnie seq. reads: 91 MB/s
bonnie seeks: 370/s
raid 0 (4 devices)
-----------------------------
dd writes: 220 MB/s
dd reads: 380 MB/s
bonnie seq. writes: 130 MB/s
bonnie seq. rewrite: 114 MB/s
bonnie seq. reads: 280 MB/s
bonnie seeks: 570/s
raid 10 (4 devices)
-----------------------------
dd writes: 90 MB/s
dd reads: 200 MB/s
bonnie seq. writes: 49 MB/s
bonnie seq. rewrite: 56 MB/s
bonnie seq. reads: 160 MB/s
bonnie seeks: 590/s
So the results are rather different from your results (both master and
slave).
What surprises me a bit is the decrease of write performance between
sigle drive and RAID 10. I've used bonnie++ 1.03e, so I'm wondering if
the 1.96 would give different results ...
All those benchmarks were performed with ext3.
Tomas
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To: pgsql-performance@postgresql.org
Cc: tv@fuzzy.cz
Subject: Re: Slow queries / commits, mis-configuration or hardware issues?
In-Reply-To: <4EC30F05.6010901@fuzzy.cz>
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