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How Many Google Machines, Really?
BoneThugND writes "I found this article on TNL.NET. It takes information from the S-1 Filing to reverse engineer how many machines Google has (hint: a lot more than 10,000).
'According to calculations by the IEE, in a paper about the Google cluster, a rack with 88 dual-CPU machines used to cost about $278,000. If you divide the $250 million figure from the S-1 filing by $278,000, you end up with a bit over 899 racks. Assuming that each rack holds 88 machines, you end up with 79,000 machines.'" An anonymous source claims
over 100,000.
A Pentium 4 dissipates around 85 W of heat. I don't know what the Xeon does, but let's be kind and say 50 W (wild guess). Using the article's "low end" estimate, that brings us to 4.7 MW!
I hope they have good ventilation...
When you can just open "Computer Architecture: A Quantitavie Approach, 3rd Edition" by Hennessy and Patterson to page 855 and find out that in summary: ...
Google has 3 sites (two west coast, one east)
Each site connected with 1 OC48
Each OC48 hooks up to 2 Foundry BigIron 8000
80 Pc's per rack * 40 racks(at an example site)
= 3200 PC's.
A google site is not a homogenous set of PC's instead there are different types of PC's that are being upgraded on different cycles based on the price/performance ratio.
If you want more info get the patterson hennessy book that I mentioned. Not the other version they sell. This one rocks way harder. You get to learn fun things like Tomosulo's algorithm.
If I am violating any copy rights feel free to remove this post.
Mainframes are optimized for batch processing. Interactive queries do not take full advantage of their vaunted I/O capacity.
Moreover, while a mainframe may be a good way to host a single copy of a database that must remain internally consistent, that's not the problem Google is solving. It's trivial for them to run their search service off of thousands of replicated copies of the Internet index. Even the largest mainframe's storage I/O would be orders of magnitude smaller than the massively parallel I/O operations done by these thousands of PCs. Google has no reason to funnel all of the independent search queries into a single machine, so they shouln't buy a system architecture designed to do that.
>>Disks are going to fail at a rate of several hundred or thousand PER DAY
that's a little over the top big guy. i've worked at a 10,000 node corp doing desktop support. We lost ONE disk perhaps a week....if that much. We often went several weeks with no disks lost.
even if you factor in multiple drives per server, say TWO (because they are servers not desktops)
Interpolate for 100,000, that's a max of 20 disks per week...on the high end.
The high-end Sun machines are designed for high availability. Not only will a CPU failure not crash the machine, the CPUs are hot swappable so you can replace a failed CPU without so much as a reboot.
Any of those 64 CPUs fails, and your system will crash.
Doesn't work like that, kid. A CPU on a high-end Sun fails, and the system will keep on running. You can swap the CPU out and replace it with a new one, the system will simply pick it up, assign threads to it, and keep on running. Had a couple of CPUs fail a little while ago... the first we users noticed of it was that the application slowed down slightly. Sysadmin just said yeah, I know, I'll replace 'em when the parts arrive this afternoon. Cool, we said. No data lost, no need to shut down or even restart our app. 'Course you gotta architect your app to deal with that - like don't have just one thread that does a crucial task, 'cos there's a chance that might be on the CPU that fails. But still, it's no big deal.
Dude, big iron is not comparable in the slightest to that dinky little dual PPro Linux 'server' you keep in your closet. A CPU can fail, on a live running system, and the machine and Solaris or AIX won't even hiccup. Your application will notice, because suddenly a couple of its threads will quit, but that's ok, software like Oracle already knows how to deal with failed transations. And if you can schedule a CPU board removal/swap, then there won't be ANY problems at all, as the OS will migrate threads to other CPUs and allow the removal or hardware.
And hey, if you want to mix and match CPU types (uSparc 2 and 3, etc), speeds, etc, no problem either. So if you wanna upgrade your server's CPUs, there will be zero downtime, you just do it a board at a time (board = 2 or 4 CPUs).
His pricing in the summary may be a bit off.
:)
:) Well, not the Asus 1400r, those are built into a 1u case, but other machines we've built for servers are very easy to build into midtowers instead. Those machines don't get gobs of memory, but do get extras like nice sound cards and CD/DVD players. The price would be the same, as they'd probably still be attaching them to the same networking equipment. 132,000 servers, and 2,682 workstations and dev machines is probably fairly close to what they have.
Every article I've read about Google's servers says they use "commodity" parts, which means they buy pretty much the same stuff we buy. They also indicate that they use as much memory as possible, and don't use hard drives, or use the drives as little as possible. From my interview with Google, they asked quite a few questions about RAID0, RAID1 (and combinations of those), I'd believe they stick in two drives to ensure data doesn't get lost due to power outages.
We get good name brand parts wholesale, which I'd expect is what they do too. So, assuming 1u Asus, Tyan, or SuperMicro machines stuffed full of memory, with hard drives big enough to hold the OS plus an image of whatever they store in memory (ramdrives?), they'd require at most 3Gb (OS) + 4Gb (ramdrive backup). I don't recall seeing dual CPU's, but we'll go with that assumption.
The nice base machine we had settled on for quite a while was the Asus 1400r, which consisted of dual 1.4Ghz PIII's, 2Gb RAM, and 20Gb and 200Gb hard drives. Our cost was roughly $1500. They'd lower the drive cost, but incrase the memory cost, so they'd probably cost about $1700, but I'm sure Google got better pricing, buying the quantity they were getting.
The count of 88 machines per rack is a bit high. You get 80u's per standard rack, but you can't stuff it full of machines, unless you get very creative. I'd suspect they have 2 switches, and a few power management units per rack. The APC's we use take 8 machines per unit, and are 1u tall. There are other power management units, that don't take up rack space, which they may be using, but only the folks at Google really know.
Assuming the maximum density, and equipment that was available as "commodity" equipment at the time, they'd have 2 Cisco 2948's and 78 servers per rack.
$1700 * 78 (servers)
+
$3000 * 2 (switches)
+
$1000 (power management)
--------
$139,600 per rack (78 servers)
Lets not forget core networking equipment. That's worth a few bucks.
Each set of 39 servers would probably be connected to their routers via GigE fiber (I couldn't imageine them using 100baseT for this) Right now we're guestimating 1700 racks. They have locations in 3 cities, so we'll assume they have at least 9 routers. They'd probably use Cisco 12000's, or something along that line. Checking eBay, you can get a nice Cisco 12008 for just $27,000, but that's the smaller one. I've toured a few places who had them, and pointed at them citing them to be just over $1,000,000.
So....
$250,000,000 (ttl expenses)
- $ 9,000,000 (routers)
------
$241,000,000
/ $ 139,600
------
1726 racks
* 78 (machines per rack)
------
134,682 machines
Google has a couple thousand employees, but we've found that our servers make *VERY* nice workstations too.
I believe this to be a more fair estimate, than the story gave. They're quoting pricing for a nice fast *CURRENT* machine, but Google has said before that they buy commodity machines. They do like we do. We buy cheap (relatively) and lots of them, just like Google does. We didn't pattern ourselves after Google, we made this decision long before Google even existed.
When *WE* decided to go this router, we looked at many options. The "provider" we had, before we went on our own, leasing space and bandwidth directly from Tier 1 providers, opted for the monolythic sy
Serious? Seriousness is well above my pay grade.