Re: Benchmark: Dell/Perc 6, 8 disk RAID 10 - Mailing list pgsql-performance

----- Original Message -----
From: "Greg Smith" <gsmith@gregsmith.com>
To: <pgsql-performance@postgresql.org>
Sent: Thursday, March 13, 2008 4:27 PM
Subject: Re: [PERFORM] Benchmark: Dell/Perc 6, 8 disk RAID 10


> On Thu, 13 Mar 2008, Joshua D. Drake wrote:
>
>> Greg Smith <gsmith@gregsmith.com> wrote:
>>>>> wal_sync_method = open_sync
>>>
>>> There was a bug report I haven't had a chance to investigate yet that
>>> suggested some recent Linux versions have issues when using
>>> open_sync. I'd suggest popping that back to the default for now
>>> unless you have time to really do a long certification process that
>>> your system runs reliably with it turned on.
>>
>> Well the default would be ugly, that's fsync, fdatasync is probably a
>> better choice in that case.
>
> I haven't found fdatasync to be significantly better in my tests on Linux
> but I never went out of my way to try and quantify it.  My understanding
> is that some of the write barrier implementation details on ext3
> filesystems make any sync call a relatively heavy operation but I haven't
> poked at the code yet to figure out why.
>
> There are really some substantial gains for WAL-heavy loads under Linux
> just waiting for someone to dig into this more.  For example, I have a
> little plan sitting here to allow opening the WAL files with noatime even
> if the rest of the filesystem can't be mounted that way, which would
> collapse one of the big reasons to use a separate WAL disk.
>
> --
> * Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD
>
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I'm ran pgbench from my laptop to the new server

My laptop is dual core with 2 gigs of ram and 1 gig enthernet connection to
server.   so i don't think the network is going to be a problem in the test.

When i look at the server memory its only consuming  463 megs.   I have the
effective cache set at 12 gigs and sharebuffer at 100megs and work mem set
to 50megs

transaction type: TPC-B (sort of)
scaling factor: 100
number of clients: 1
number of transactions per client: 10
number of transactions actually processed: 10/10
tps = 20.618557 (including connections establishing)
tps = 20.618557 (excluding connections establishing)

transaction type: TPC-B (sort of)
scaling factor: 100
number of clients: 10
number of transactions per client: 10
number of transactions actually processed: 100/100
tps = 18.231541 (including connections establishing)
tps = 18.231541 (excluding connections establishing)

transaction type: TPC-B (sort of)
scaling factor: 100
number of clients: 10
number of transactions per client: 100
number of transactions actually processed: 1000/1000
tps = 19.116073 (including connections establishing)
tps = 19.116073 (excluding connections establishing)

transaction type: TPC-B (sort of)
scaling factor: 100
number of clients: 40
number of transactions per client: 1000
number of transactions actually processed: 40000/40000
tps = 20.368217 (including connections establishing)
tps = 20.368217 (excluding connections establishing)