Thread: Hardware spec

Hardware spec

From
Willo van der Merwe
Date:
Hi guys,

I'm have the rare opportunity to spec the hardware for a new database
server. It's going to replace an older one, driving a social networking
web application. The current server (a quad opteron with 4Gb of RAM and
80Gb fast SCSI RAID10) is coping with an average load of ranging between
1.5 and 3.5.

The new machine spec I have so far:
    2 x Intel Xeon 2.33 GHz Dual Core Woodcrest Processors
    4 Gb RAM
    5x73 GB Ultra320 SCSI RAID 5 (288 GB storage)

I've heard that RAID 5 is not necessarily the best performer. Also, are
there any special tricks when partition the file system?

Regards,

Willo


Re: Hardware spec

From
Richard Huxton
Date:
Willo van der Merwe wrote:
> Hi guys,
>
> I'm have the rare opportunity to spec the hardware for a new database
> server. It's going to replace an older one, driving a social networking
> web application. The current server (a quad opteron with 4Gb of RAM and
> 80Gb fast SCSI RAID10) is coping with an average load of ranging between
> 1.5 and 3.5.
>
> The new machine spec I have so far:

What's the limiting factor on your current machine - disk, memory, cpup?

--
   Richard Huxton
   Archonet Ltd

Re: Hardware spec

From
Willo van der Merwe
Date:
Richard Huxton wrote:
> Willo van der Merwe wrote:
>> Hi guys,
>>
>> I'm have the rare opportunity to spec the hardware for a new database
>> server. It's going to replace an older one, driving a social networking
>> web application. The current server (a quad opteron with 4Gb of RAM and
>> 80Gb fast SCSI RAID10) is coping with an average load of ranging between
>> 1.5 and 3.5.
>>
>> The new machine spec I have so far:
> What's the limiting factor on your current machine - disk, memory, cpup?
I'm a bit embarrassed to admit that I'm not sure. The reason we're
changing machines is that we might be changing ISPs and we're renting /
leasing the machines from the ISP.

Re: Hardware spec

From
Jean-David Beyer
Date:
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Willo van der Merwe wrote:
> Richard Huxton wrote:
>> Willo van der Merwe wrote:
>>> Hi guys,
>>>
>>> I'm have the rare opportunity to spec the hardware for a new database
>>>  server. It's going to replace an older one, driving a social
>>> networking web application. The current server (a quad opteron with
>>> 4Gb of RAM and 80Gb fast SCSI RAID10) is coping with an average load
>>> of ranging between 1.5 and 3.5.
>>>
>>> The new machine spec I have so far:
>> What's the limiting factor on your current machine - disk, memory,
>> cpup?
> I'm a bit embarrassed to admit that I'm not sure. The reason we're
> changing machines is that we might be changing ISPs and we're renting /
> leasing the machines from the ISP.
>
Before you get rid of the current ISP, better examine what is going on with
the present setup. It would be good to know if you are memory, processor, or
IO limited. That way you could increase what needs to be increased, and not
waste money where the bottleneck is not.

- --
  .~.  Jean-David Beyer          Registered Linux User 85642.
  /V\  PGP-Key: 9A2FC99A         Registered Machine   241939.
 /( )\ Shrewsbury, New Jersey    http://counter.li.org
 ^^-^^ 07:10:01 up 28 days, 10:32, 4 users, load average: 5.48, 4.77, 4.37
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Version: GnuPG v1.4.5 (GNU/Linux)
Comment: Using GnuPG with CentOS - http://enigmail.mozdev.org

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vmXnoJO0vm/A/f/Ol0TOy6o=
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Re: Hardware spec

From
Willo van der Merwe
Date:
Jean-David Beyer wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Willo van der Merwe wrote:
>
>> Richard Huxton wrote:
>>
>>> Willo van der Merwe wrote:
>>>
>>>> Hi guys,
>>>>
>>>> I'm have the rare opportunity to spec the hardware for a new database
>>>>  server. It's going to replace an older one, driving a social
>>>> networking web application. The current server (a quad opteron with
>>>> 4Gb of RAM and 80Gb fast SCSI RAID10) is coping with an average load
>>>> of ranging between 1.5 and 3.5.
>>>>
>>>> The new machine spec I have so far:
>>>>
>>> What's the limiting factor on your current machine - disk, memory,
>>> cpup?
>>>
>> I'm a bit embarrassed to admit that I'm not sure. The reason we're
>> changing machines is that we might be changing ISPs and we're renting /
>> leasing the machines from the ISP.
>>
>>
> Before you get rid of the current ISP, better examine what is going on with
> the present setup. It would be good to know if you are memory, processor, or
> IO limited. That way you could increase what needs to be increased, and not
> waste money where the bottleneck is not.
>
Good advice. After running a vmstat and iostat, it is clear, to my mind
anyway, that the most likely bottleneck is IO, next is probably some
more RAM.
Here's the output:
procs -----------memory---------- ---swap-- -----io---- --system--
----cpu----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in    cs us sy
id wa
 0  0  29688  80908 128308 3315792    0    0     8    63    6     8 17
2 80  1


avg-cpu:  %user   %nice    %sys %iowait   %idle
          17.18    0.00    1.93    0.81   80.08

Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
sda              14.57        66.48       506.45   58557617  446072213
sda1              0.60         0.27         4.70     235122    4136128
sda2              0.38         0.77         2.27     678754    2002576
sda3              2.37         0.49        18.61     429171   16389960
sda4              0.00         0.00         0.00          2          0
sda5              0.71         0.66         5.46     578307    4807087
sda6              0.03         0.01         0.24       6300     214196
sda7              0.02         0.00         0.19       2622     165992
sda8             60.19        64.29       474.98   56626211  418356226


Re: Hardware spec

From
Florian Weimer
Date:
* Willo van der Merwe:

> Good advice. After running a vmstat and iostat, it is clear, to my
> mind anyway, that the most likely bottleneck is IO, next is probably
> some more RAM.

> Here's the output:
> procs -----------memory---------- ---swap-- -----io---- --system--
> ----cpu----
> r  b   swpd   free   buff  cache   si   so    bi    bo   in    cs us
> sy id wa
> 0  0  29688  80908 128308 3315792    0    0     8    63    6     8 17
> 2 80  1

You need to run "vmstat 10" (for ten-second averages) and report a
couple of lines.

> avg-cpu:  %user   %nice    %sys %iowait   %idle
>          17.18    0.00    1.93    0.81   80.08

Same for iostat.

Your initial numbers suggest that your server isn't I/O-bound, though
(the percentage spent in iowait is much too small, and so are the tps
numbers).

--
Florian Weimer                <fweimer@bfk.de>
BFK edv-consulting GmbH       http://www.bfk.de/
Kriegsstraße 100              tel: +49-721-96201-1
D-76133 Karlsruhe             fax: +49-721-96201-99

Re: Hardware spec

From
Florian Weimer
Date:
* Willo van der Merwe:

> Florian Weimer wrote:
>> You need to run "vmstat 10" (for ten-second averages) and report a
>> couple of lines.

> 2 80  1
> 5  0  61732  37052  28180 3431956    0    0    14   987 2320  2021 38

> sda3              3.30         0.00        26.40          0        264
> sda8             97.90         0.00       783.20          0       7832

These values don't look I/O bound to me.  CPU usage is pretty low,
too.

--
Florian Weimer                <fweimer@bfk.de>
BFK edv-consulting GmbH       http://www.bfk.de/
Kriegsstraße 100              tel: +49-721-96201-1
D-76133 Karlsruhe             fax: +49-721-96201-99

Re: Hardware spec

From
Willo van der Merwe
Date:
Florian Weimer wrote:
> You need to run "vmstat 10" (for ten-second averages) and report a
> couple of lines.
>
procs -----------memory---------- ---swap-- -----io---- --system--
----cpu----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in    cs us sy
id wa
 1  0  61732  47388  27908 3431344    0    0    10    65    1     4 17
2 80  1
 5  0  61732  37052  28180 3431956    0    0    14   987 2320  2021 38
4 56  2
 1  0  61620  43076  28356 3432256    0    0     0   367 1691  1321 28
3 67  1
 3  0  61620  37620  28484 3432740    0    0     0   580 4088  6792 40
5 54  1
 2  0  61596  33716  28748 3433520    0    0    24   415 2087  1890 44
4 49  2
 3  0  61592  45300  28904 3416200    3    0    61   403 2282  2154 41
4 54  1
 7  0  61592  30172  29092 3416964    0    0    19   358 2779  3478 31
6 63  1
 1  0  61580  62948  29180 3417368    6    0    27   312 3632  4396 38
4 57  1
 1  0  61444  62388  29400 3417964    0    0     6   354 2163  1918 31
4 64  1
 2  0  61444  53988  29648 3417988    0    0     0   553 2095  1687 33
3 63  1
 1  0  61444  63988  29832 3418348    0    0     6   352 1767  1424 22
3 73  1
 1  1  61444  51148  30052 3419148    0    0    50   349 1524   834 22
3 74  2
 1  0  61432  53460  30524 3419572    7    0     7   868 4434  6706 43
6 49  2
 1  0  61432  58668  30628 3420148    0    0     0   284 1785  1628 27
3 69  1

iostat sda8 is the where the pg_data resides, sda3 is /var/log
avg-cpu:  %user   %nice    %sys %iowait   %idle
          17.36    0.00    1.96    0.82   79.86
Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
sda3              2.38         0.49        18.71     432395   16672800
sda8             62.34        74.46       491.74   66345555  438143794

avg-cpu:  %user   %nice    %sys %iowait   %idle
          30.50    0.00    3.57    1.70   64.22
Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
sda3              5.60         0.00        44.80          0        448
sda8            120.20       134.40       956.00       1344       9560

avg-cpu:  %user   %nice    %sys %iowait   %idle
          20.68    0.00    3.43    1.35   74.54
Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
sda3              3.30         0.00        26.40          0        264
sda8             97.90         0.00       783.20          0       7832

avg-cpu:  %user   %nice    %sys %iowait   %idle
          22.31    0.00    2.75    0.68   74.27
Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
sda3              2.10         0.00        16.78          0        168
sda8             60.34         0.80       481.92          8       4824

avg-cpu:  %user   %nice    %sys %iowait   %idle
          11.65    0.00    1.60    1.03   85.72
Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
sda3              1.70         0.00        13.61          0        136
sda8             59.36         0.00       474.87          0       4744


Re: Hardware spec

From
Decibel!
Date:
On Thu, Sep 06, 2007 at 11:26:46AM +0200, Willo van der Merwe wrote:
> Richard Huxton wrote:
> >Willo van der Merwe wrote:
> >>Hi guys,
> >>
> >>I'm have the rare opportunity to spec the hardware for a new database
> >>server. It's going to replace an older one, driving a social networking
> >>web application. The current server (a quad opteron with 4Gb of RAM and
> >>80Gb fast SCSI RAID10) is coping with an average load of ranging between
> >>1.5 and 3.5.
> >>
> >>The new machine spec I have so far:
> >What's the limiting factor on your current machine - disk, memory, cpup?
> I'm a bit embarrassed to admit that I'm not sure. The reason we're
> changing machines is that we might be changing ISPs and we're renting /
> leasing the machines from the ISP.

Get yourself the ability to benchmark your application. This is
invaluable^W a requirement for any kind of performance tuning.
--
Decibel!, aka Jim Nasby                        decibel@decibel.org
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)

Attachment

Re: Hardware spec

From
Willo van der Merwe
Date:
Decibel! wrote:
> On Thu, Sep 06, 2007 at 11:26:46AM +0200, Willo van der Merwe wrote:
>
>> Richard Huxton wrote:
>>
>>> Willo van der Merwe wrote:
>>>
>>>> Hi guys,
>>>>
>>>> I'm have the rare opportunity to spec the hardware for a new database
>>>> server. It's going to replace an older one, driving a social networking
>>>> web application. The current server (a quad opteron with 4Gb of RAM and
>>>> 80Gb fast SCSI RAID10) is coping with an average load of ranging between
>>>> 1.5 and 3.5.
>>>>
>>>> The new machine spec I have so far:
>>>>
>>> What's the limiting factor on your current machine - disk, memory, cpup?
>>>
>> I'm a bit embarrassed to admit that I'm not sure. The reason we're
>> changing machines is that we might be changing ISPs and we're renting /
>> leasing the machines from the ISP.
>>
>
> Get yourself the ability to benchmark your application. This is
> invaluable^W a requirement for any kind of performance tuning.
>
I'm pretty happy with the performance of the database at this stage.
Correct me if I'm wrong, but AFAIK a load of 3.5 on a quad is not
overloading it. It also seem to scale well, so if application's demand
increases I see a minimal increase in database server load.

I was just looking for some pointers as to where to go to ITO hardware
for the future, as I can now spec a new  machine. I mean is it really
worth while going for one of those RAID controllers with the battery
backed cache, for instance. If so, are there any specific ones to look
out for? Which is better RAID 5, a large RAID 10 or smaller RAID 10's?
Should I bother with RAID at all?



Re: Hardware spec

From
"Claus Guttesen"
Date:
> > Get yourself the ability to benchmark your application. This is
> > invaluable^W a requirement for any kind of performance tuning.
> >
> I'm pretty happy with the performance of the database at this stage.
> Correct me if I'm wrong, but AFAIK a load of 3.5 on a quad is not
> overloading it. It also seem to scale well, so if application's demand
> increases I see a minimal increase in database server load.
>
> I was just looking for some pointers as to where to go to ITO hardware
> for the future, as I can now spec a new  machine. I mean is it really
> worth while going for one of those RAID controllers with the battery
> backed cache, for instance. If so, are there any specific ones to look
> out for? Which is better RAID 5, a large RAID 10 or smaller RAID 10's?
> Should I bother with RAID at all?

These issues have been covered before. You may want to search the
archives and get the relevant pointers.

--
regards
Claus

When lenity and cruelty play for a kingdom,
the gentlest gamester is the soonest winner.

Shakespeare