Обсуждение: Small DB Server Advice

We have a web application for which we intend to run the database on a
dedicated server.

We hope by the end of 2008 to have 10 companies accessing 10 instances
of the database for this application. The dump file of each database is
likely to be less than 100MB at the end of the year. The databases are
read-heavy.

I'm thinking of something along the following lines:

(https://secure.dnuk.com/systems/r325hs-1u.php?configuration=7766)

    4 x 147GB 15000 rpm SCSI in RAID 10 with 320-1 RAID CARD + 64MB cache BBU
    2x Intel Xeon E5405 / 4x 2.00GHz / 1333MHz FSB / 12MB cache
    6GB RAM

    Cost around 2320 GBP -- it would be great to get it under 2000
    Needs to be in the UK.

I would be grateful for any comments. I'm particularly out of date about
the best processors to go for. DNUK also have Opteron as an option.

Rory

On Wed, 13 Feb 2008, Rory Campbell-Lange wrote:
>    4 x 147GB 15000 rpm SCSI in RAID 10 with 320-1 RAID CARD + 64MB cache BBU
>    2x Intel Xeon E5405 / 4x 2.00GHz / 1333MHz FSB / 12MB cache
>    6GB RAM
>
>    Cost around 2320 GBP -- it would be great to get it under 2000
>    Needs to be in the UK.

> I would be grateful for any comments. I'm particularly out of date about
> the best processors to go for. DNUK also have Opteron as an option.

That sounds pretty good. It should run postgres fairly well, especially if
you have quite a few parallel queries coming in. You won't need a bigger
BBU cache if it's read-heavy. You'll have eight CPU cores, which is good.
And RAID 10 is good.

As for Intel/AMD, I think they're neck-and-neck at the moment. Both are
fast.

Of course, we over here have no idea how much actual read traffic there
will be, so you may be massively over-providing or it may be woefully
inadequate, but this machine looks like a fairly good buy for the price.

Matthew

--
No trees were killed in the sending of this message.  However a large
number of electrons were terribly inconvenienced.

Matthew wrote:
> On Wed, 13 Feb 2008, Rory Campbell-Lange wrote:
>>    4 x 147GB 15000 rpm SCSI in RAID 10 with 320-1 RAID CARD + 64MB
>> cache BBU
>>    2x Intel Xeon E5405 / 4x 2.00GHz / 1333MHz FSB / 12MB cache
>>    6GB RAM
>>
>>    Cost around 2320 GBP -- it would be great to get it under 2000
>>    Needs to be in the UK.
>
>> I would be grateful for any comments. I'm particularly out of date about
>> the best processors to go for. DNUK also have Opteron as an option.
>
> That sounds pretty good. It should run postgres fairly well, especially
> if you have quite a few parallel queries coming in. You won't need a
> bigger BBU cache if it's read-heavy. You'll have eight CPU cores, which
> is good. And RAID 10 is good.

In my experience, battery backed cache is always worth the money. Even
if you're mostly select, you will have some updates. And it'll also pick
up other write activity onthe system...


//Magnus

On Wed, 13 Feb 2008, Magnus Hagander wrote:
>> On Wed, 13 Feb 2008, Rory Campbell-Lange wrote:
>>>    4 x 147GB 15000 rpm SCSI in RAID 10 with 320-1 RAID CARD + 64MB cache
>>> BBU

> In my experience, battery backed cache is always worth the money. Even if
> you're mostly select, you will have some updates. And it'll also pick up
> other write activity onthe system...

Of course. My point was that 64MB should be quite sufficient if most
accesses are reads. We have a few machines here with 2GB BBU caches as we
do LOTS of writes - that sort of thing probably isn't necessary here.

Matthew

--
I suppose some of you have done a Continuous Maths course. Yes? Continuous
Maths? <menacing stares from audience> Whoah, it was like that, was it!
                                        -- Computer Science Lecturer

On Wed, 13 Feb 2008, Rory Campbell-Lange wrote:

> (https://secure.dnuk.com/systems/r325hs-1u.php?configuration=7766)
>    4 x 147GB 15000 rpm SCSI in RAID 10 with 320-1 RAID CARD + 64MB cache BBU

That's running the LSI Megaraid SCSI controller.  Those are solid but not
the best performers in their class, particularly on writes.  But given
your application description (1GB data in a year and read-heavy) that card
running a 4-spindle RAID10 should be overkill.

> I'm particularly out of date about the best processors to go for. DNUK
> also have Opteron as an option.

Current Intel chips benchmark better, occasionally you'll find people who
claim the better multi-CPU memory model in the Opteron systems give them
better performance at high loads but that's difficult to quantify.
There's not a huge difference in any case.  You're probably going to
bottleneck on either disk or how fast DDR2 memory goes anyway and both
sets of products are competative right now.

--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD