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Ask Slashdot: Building a Cheap Computing Cluster?
New submitter jackdotwa writes "Machines in our computer lab are periodically retired, and we have decided to recycle them and put them to work on combinatorial problems. I've spent some time trawling the web (this Beowulf cluster link proved very instructive) but have a few reservations regarding the basic design and air-flow. Our goal is to do this cheaply but also to do it in a space-conserving fashion. We have 14 E8000 Core2 Duo machines that we wish to remove from their cases and place side-by-side, along with their power supply units, on rackmount trays within a 42U (19", 1000mm deep) cabinet." Read on for more details on the project, including some helpful pictures and specific questions.
jackdotwa continues: "Removing them means we can fit two machines into 4U (as opposed to 5U). The cabinet has extractor fans at the top and the PSUs and motherboard fans (which pull air off the CPU and remove it laterally — (see images) face in the same direction. Would it be best to orient the shelves (and thus the fans) in the same direction throughout the cabinet, or to alternate the fan orientations on a shelf-by-shelf basis? Would there be electrical interference with the motherboards and CPUs exposed in this manner? We have a 2 ton (24000 BTU) air-conditioner which will be able to maintain a cool room temperature (the lab is quite small), judging by the guide in the first link. However, I've been asked to place UPSs in the bottom of the cabinet (they will likely be non-rackmount UPSs as they are considerably cheaper). Would this be, in anyone's experience, a realistic request (I'm concerned about the additional heating in the cabinet itself)? The nodes in the cabinet will be diskless and connected via a rack-mountable gigabit ethernet switch to a master server. We are looking to purchase rack-mountable power distribution units to clean up the wiring a little. If anyone has any experience in this regard, suggestions would be most appreciated."
A beowulf cluster of these! FP
throwing gear away or giving it away. Just because you have it doesn't mean to have to, or should use it. If energy and space efficiency are important, you need to carefully consider what you are reusing. Sure, what you have now may have already fallen off the depreciation books, but if it's going to draw twice the power and take double the space that newer used kit would, it may not be the best option, even when the other options involve purchasing new or newer-used gear.
Not saying you need to do this, just recommending you keep an open mind and don't be afraid to do what needs to be done if you find it necessary.
I work for the Department of Redundancy Department.
You'll need to consider how you're going to provision and maintain a collection of systems.
Our company currently uses the ROCKS cluster distribution, which is a CentOS-based distribution that provisions, monitors and manages all of the compute nodes. It's very easy to have a working cluster set up in a short amount of time, but it's somewhat quirky in that you can't fully patch all pieces of the software without breaking the cluster.
One thing that I really like about ROCKS is their provisioning tool which is called the "Avalanche Installer". It uses bittorrent to load the OS and other software on each compute node as it comes online and it's exceedingly fast.
I installed ROCKS on a head node, then was able to provision 208 HP BL480c blades within an hour and a half.
Check it out at www.rockclusters.org
Don't anthropomorphize computers, they don't like it.
Slashdotters only imagine building Beowulf clusters. This is the first time anyone's been serious about it.
I've been working in academic HPC for over a decade. Unless you are building a simple 2-3 node cluster to learn how a cluster works (scheduler, resource broker and such things), it's not worth your time. What you save in hardware, you'll lose in lost time, electricity, cooling, etc.
If you're interested in actual research, take one computer, install an AMD 7950 for $300, and you will almost certainly blow the doors off a cluster cobbled from old Core 2 Duo's, and you'll save more than $300 in electricity.
Seriously, it isn't worth your effort - especially if you want something reliable. People who set out to make homemade clusters find out the hard way about design issues that reduce the life expectancy of their cluster. There are professionals who can build you a proper cluster for not a lot of money if you really want your own, or even better you can rent time on someone else's cluster.
If the goal of this is reliable performance, you're absolutely right. But if the goal is to teach yourself about distributed computing, networking, diskless booting, all the issues that come up in building a cluster, on the cheap - then this is a great idea. Just don't expect much from the end product - you'll get more performance a modern box with 10s of cores on a single MB.
It's 2013 don't build your own cluster just use AWS EC2 spot instances.
An EC2 "High CPU Medium" instance is probably close to his Core 2 Duo's (it has 1.7GB RAM + two cores of 2.5 EC2 compute units each (each ECU is equivalent to a 2007 era 1.2Ghz Xeon).
Current spot pricing is $0.018/hour, so a month would cost him around $12.96. (not including storage, add about a dollar for 10GB of EBS disk space).
If his computers use 150W of power each, at $0.12/KWh, they'll cost exactly $0.018 -- the same price as an EC2 instance excluding storage.
However spot pricing is not guaranteed, so he'll have to be prepared to shut down his instances when the spot price rises above what he's willing to pay -- full price for the instance is $0.145/hour, but he could get that down to $0.09/hour if he's willing to pay $161 to reserve the instance for 3 years.
SPECfp2006 rate results:
...sell the E8xxx series PC's in boxes for$100 a peice with windows licence
e8600 34
i7-3770 130
x4 the performance
and use the $1400 towards buying Qty.4 lga1155 motherboards (4x$80), 4 unlocked K series i7's (4x$230) and 4x8Gb of DDR3 RAM (4x$40), 4x ~3-400W budget power supplies (4x $30) = $1520
Use a specialized clustering OS (linux) and have a smaller, easier to manage system, with lots more DDR 3 memory and lower electricity (and AC electricity) bill....