postgresql-performance using sysbench

Kris Kennaway kris at FreeBSD.org
Mon Jan 28 12:34:39 PST 2008


Claus Guttesen wrote:
>>>> Ubuntu 7.10:
>>>>
>>>> grep "transactions:" sysbench-clients-24|sort
>>>> transactions:                        10000  (2354.49 per sec.)
>>>> transactions:                        10001  (2126.28 per sec.)
>>>> transactions:                        10001  (2215.52 per sec.)
>>>> transactions:                        10001  (2236.03 per sec.)
>>>>
>>>> FreeBSD 7.0 stable as of Jan. 28'th:
>>>>
>>>> grep "transactions:" sysbench-clients-24|sort
>>>> transactions:                        10001  (1600.36 per sec.)
>>>> transactions:                        10002  (1963.95 per sec.)
>>>> transactions:                        10005  (1973.17 per sec.)
>>>>
>>>> In other runs FreeBSD also seems to trail Ubuntu. Are there any knobs
>>>> I could try on FreeBSD?
>>> I think the excellent results Kris got with FreeBSD were significantly
>>> helped by patching postgresql to remove setproctitle().
>> You don;t need to patch postgresql for that, all you need to do is turn that
>> off.
>>
>> update_process_title = off in postgresql.conf and then restart the daemon.
> 
> I found the setting and set it to off but no real difference in performance.
> 
>>>   from the sysbench line I see this is OLTP benchmark which should mean
>>> a lot of write transactions, and I've consistently seen much better file
>>> system write performance on Linux than on FreeBSD. No tuning can help here.
> 
> Yes, that is correct. I wanted to conduct a r/w test. But if it's down
> to the fs itself I will just leave it atm. I will probably deploy the
> server on FreeBSD anyway since we probably won't reach that many
> writes in the foreseable future and FreeBSD is what I do best.
> 
> Will zfs be able to achieve better performance? I guess that ufs2 will
> remain more or less in the state it is in now.
> 

I went through this in detail in a thread on -stable recently (Subject: 
Performance!).  Rather than me going over all of this again, can you 
please read that thread in detail and get back to me once you have 
applied all of the discussion there to your case.

Kris



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