Forum OpenACS Q&A: Hardware Configuration for an ACS Site

1: Hardware Configuration for an ACS Site

Posted by Hamilton Chua on 11/12/01 07:34 AM

Hello,

I am some what ready with my application and have gotten to the point of deciding which production hardware to use with OpenACS4.

Can anyone give recommendations of the hardware configs that would comforably allow be to support 50K to 100K users.

I have the following configs in mind.

Dual Processor Intel Pentium III- 1.13Ghz w/512k cache
512MB SDRAM memory
2x 18GB 10k rpm Hot Plug Hard Drive
Add-In RAID 1 card
1x Internal 20/40GB DDS-4 Tape drive w/39160 SCSI Controller
Red Hat Linux 7.1 Operating System
2 U chassis size

What do you guys think ?

2: Response to Hardware Configuration for an ACS Site (response to 1)

Posted by Patrick Giagnocavo on 11/12/01 08:46 AM

Single Athlon 1800+ XP cpu would be my preference, since a single faster CPU is generally zippier than 2 slower CPUs. While the Athlon is hotter, I doubt that it is any hotter than 2 x P3s.

1GB RAM (memory is cheap)

the rest sounds good.

3: Response to Hardware Configuration for an ACS Site (response to 1)

Posted by S. Y. on 11/12/01 09:14 AM

About processors, I note that Hamilton is selecting CPUs with 512K caches, which is a good thing. Intel is not marketing their PIII parts with the larger L2 caches, although they are really supposed to perform rather well. If I understand correctly, web servers tend to thrash cache and having larger L2 caches makes a substantial difference.

I'm rather surprised that you can cram a DDS-4 internal tape drive into a 2U chassis, but if you can, well, that's a great solution. If your drives are also going to be on a RAID controller, I am wondering why you've selected a 2-channel Ultra160 SCSI controller for the tape drive. Also, I'm a little more tempted to keep a rather expensive peripheral like a DDS-4 tape drive as an external device, simply because a fine resource isn't utterly tied down to one machine. But that's just me.

Personally I'd be more tempted to stick with a bunch of 9GB Ultra160 drives, but I don't know how many drives your 2U chassis can hold.

Red Hat Linux 7.2 is out. You can pick up a set of installation CDs for $4 at www.cheapbytes.com. RH 7.2 has ext3 support in the kernel. If you compile your own from a recent version, it's pretty darned easy to patch in ext3 support (the ext3 code was merged in 2.4.14-pre2 apparently).
Patrick's right about RAM. It's cheap now, so you should think about a gig of quality ECC stuff. If there's anything you should consider losing, it's the hot-pluggability of your hard drives.

4: Response to Hardware Configuration for an ACS Site (response to 1)

Posted by Roberto Mello on 11/12/01 04:32 PM

Are your Hard Drives SCSI? Your application is going to be I/O bound, so getting fast, more reliable disks will help you.

5: Response to Hardware Configuration for an ACS Site (response to 1)

Posted by Jun Yamog on 11/12/01 05:12 PM

Hi Guys,

Yup Sean I have to cram in a DDS-4 drive there. I am the one who picked the hardware. Although I am trying to get the higher ups to buy an autoloader for God sake. Those are 18G 10K rpm SCSI disks that holds 4MB cache, although the 15K is really good but it does cost a lot. I am also gunning for a 128MB RAID controller. This is basically a Dell PowerEdge 2550. This should initially give me RAID 1 then RAID 10 when I add 2 more hardisk to fill up 4 bays. The fill up the 2 DIMM slots left with all the memory that money can buy when its upgrade time. Although the IBM x330 looks good too.

Now that I have seen it, I think I made a typo Hamilton. We are trying to reach the 4K budget mark. I am sure that the server can not be at 4K with dual procs. Please make it a Single processor.

Any ACS 4.x platform (OpenACS 4.2, ACS 4.2, ACS Java, etc.) has this complex permission system. Given the choice of OpenACS 4 can the hardware that is written by Hamilton above be enough for 20 simultaneous users? From what I have read on some threads around here the ACS permissions is really a heavy query since it involved acs_objects. Does anyone have any hard numbers how fast is a page load for an OpenACS site that has 300K acs_objects, 100K for users objects and 200K for other ACS objects?

Has any one done some benchmarking on OpenACS 4 already? Can someone get give the details on how the permissions was tested, hardware specs etc. So maybe it might help me estimate how much hardware beef I would need.

Hmmmm now that I am thinking of it 300K rows... that should be long enough for a non modem user to notice.
I believe that there is already a patch for the permissions where in a view is used rather the acs_objects table. Will OpenACS 4.2 permission queries be better then ACS 4.2? Or be exactly the same. I think optimizing the permissions system will be top priority for Don once OpenACS 4.2 is released. I am I right will the optimization of ACS permission is high on the list after the release of OpenACS 4.2?

6: Response to Hardware Configuration for an ACS Site (response to 1)

Posted by Jon Griffin on 11/12/01 05:28 PM

You need at least a gig of memory. I would fill it up. 1 gig sticks are only $130 and 512's are almost free.

Dual CPU is fine and is better than a single slightly faster single CPU. Remember 2 cpus can do 2 tasks at once. Try that on your single board.

I wouldn't bother with RAID 1. If you are going to buy the hardware get a card that supports RAID 10 (or 0+1). Of course you need double the drives for that but in reality I am getting rid of my RAID and sticking (in Oracles case) logs and etc on 3 or more different drives. Add swap space to all of them and you are flying.

If this is a life or death, lose your job if you have any downtime then by all means use RAID. If not, drives are so reliable today that you will, most likely, outgrow your drive before it fails.

Having things on 2 or more physical drives adds reliability (and of course cuts your MTBF, but I am willing to take that risk) and lets your controller work much better.

Of course, this is my opinion and I am sure someone will tell me I am full of %^&* but ....

7: Response to Hardware Configuration for an ACS Site (response to 1)

Posted by Don Baccus on 11/12/01 07:33 PM

I'm with the others - fill 'er up with RAM. Buying the Tualatin (512K L2 cache) is a good move if you're going with a Dell box. Penguin Computing sells Athlon solutions, check this out:

http://www.penguincomputing.com/store/configurator.php

With 2x1.2HZ Athlon XPs, 256MB RAM and 4 18GB 10K SCSI drives and a network card, you're out $3800 and change. Their memory prices are high, so you could buy three 256MB DDRs from Crucial (registered, ECC) for about $45/each and still hit 1GB RAM on your $4K budget. I think MuseaTech's bought from Penguin before and are happy but don't take my word for it, you might want to email Talli Somekh.

Solving general performance issues will certainly be of very high priority once we get a solid release out the door...

8: Response to Hardware Configuration for an ACS Site (response to 1)

Posted by Jun Yamog on 11/13/01 03:28 AM

Yup I agree with John. But putting up another CPU in the initial purchase will go beyond 4K. I have removed some RAM and will save that up on the upgrade phase, since adding RAM does not require any reconfiguration on software. I had to save some bucks there. Pretty bad decision but that is the only area that I can save some bucks initially. I will try to spend more money on things that must be purchased initially like HD, RAID controller and backup device. This components must be in the box since if I where to adde them after I would probably need to backup restore the box.

I will also forgo the Penguin Computing option, its really nice especially the AMD. There is also Pogo Linux. But this vendors seems to have in the same price range of Dell, I guess I now under stand why VA Linux had to go. I am looking at http://www.fnordsystems.com, they look techincal enough and cheap. Anybody have opinions about fnord?

Anybody had benchmarked an OpenACS site?