Editing 1737: Datacenter Scale

{{comic
| number    = 1737
| date      = September 23, 2016
| title     = Datacenter Scale
| image     = datacenter_scale.png
| titletext = Asimov's Cosmic AC was created by linking all datacenters through hyperspace, which explains a lot. It didn't reverse entropy--it just discarded the universe when it reached end-of-life and ordered a new one.
}}

==Explanation==
This comic expands, to the limit, the strategy that it's a net cost saving to allow cheap hardware to fail and simply replace it than to have robust but much more expensive systems to start with. The technique was made famous by [https://books.google.com/books?id=zdlZ2rrcZWEC&pg=PA19&lpg=PA19#v=onepage&q&f=false Google circa 1999,] when its successful cost-effective server designs were actually using sub-consumer, nearly junk, hardware. 

{{w|RAID}} ("redundant array of independent disks") is a technology that splits data across several hard drives as if they were one. RAID comes in several levels (varieties) which have different applications, but one of the big applications of RAID is creating mirrored hard disks that back each other up. If one disk drive in such a RAID fails, no data is lost.

However, RAID is complicated to configure, so you don't want to be constantly setting it up. An alternative technique for data centers is, therefore, to simply send the data to several servers at once. This makes maintenance easier, but without RAID, one hard disk crash basically breaks the server. However, this is what [[Hairbun]] is doing since their scale is so large that fixing individual servers actually more expensive than simply buying a new one for replacement, and instead of fixing the drive they throw away the machine. (More about this approach will be explained later on)

From here, the comic starts to exaggerate. Nowadays, servers can be made extremely small ("{{w|Blade server}}s") and dozens of servers can be attached to one {{w|19-inch rack}} in a data center. Rather than going to the effort of unplugging and unscrewing one blade from the rack, when a blade fails at [[Cueball]]'s data center they just throw away the rack, and [[Ponytail]] agrees and mildly mocks Hairbun for replacing one server.

[[Hairy]]'s data center goes one step further - they have so many servers that they would constantly have to be throwing away and replacing racks, so instead they just build a new room when one rack fails. This would be currently possible with small modular data centers that are built in shipping containers for easy transport and can be linked together to expand capacity. Here the cargo-container "room" with the failure would be quickly swapped with a fresh one. Cueball adds "like Google!" - [[Randall]] previously mentioned {{w|Google}}'s approach to hard drive failures in the ''[[what if? (blog)|what if?]]'' article ''{{what if|63|Google's Datacenters on Punch Cards}}''. Back in [http://static.googleusercontent.com/media/research.google.com/de//archive/disk_failures.pdf 2007] they had one failure every few minutes, which might have increased hugely since then.

Finally [[Megan]] appears and her company, of course, breaks the scale of silliness in exaggeration. She says that they don't have any fire extinguishers (neither {{w|Fire sprinkler system|regular sprinklers}} nor the systems that deploy gasses like FM-200 which alter the room air's ability to sustain a fire). Rather, they just rope the center off, thus letting the data center burn down. Then they simply move a town over and build a new one. This may indicate they are so big that the entire town will burn down if their center catches fire, or else they did not have to skip town. Alternatively, they just leave the center burning and this may cause problems in that town, so they simply flee the premises. 

Most big internet companies do have multiple redundant data centers around the world, in order to increase speeds for users in different countries, but Megan's idea would be very expensive, result in increased {{w|Latency (engineering)|latency}}, possibly kill people (either in their company, or other people in the town, since they do not try to put out the fire), and cause severe destruction of properties in addition to their own.  These last two items would result in additional litigation and fines, and potentially jail sentences for the people charged with implementing the policy.  They may also result in other towns being unwilling to take their business, out of fear they will wind up burning too.

Hairy still thinks that it makes sense, while Cueball wonders what difference the roping off does. This could again be a reference to the fact that they just let the buildings burn without bothering about the local consequences, and the next step is just one more step towards the extreme of the title text. Or, he's contemplating that they're just wasting more time by roping it off.

This comic references how, as data requirements expand, the cost of time eventually outweighs the cost of hardware at ever increasing scales (drive, rack, room, building). While this comic takes this to the extreme, with whole buildings being destroyed for simple flaws, the concept is not as far-fetched as it seems if "thrown out" is taken to include being sold to equipment refurbishers. It could indeed be cost effective for a large data services provider to resell racks or even whole data center modules at some significant fraction of their "as new" price as opposed expending the time and effort to attempt a repair. The equipment refurbisher would then rely on a {{w|competitive advantage|cost advantage}} like cheaper labor to repair the flaw and sell it back to Google or another company with less demanding requirements.  Equipment rental firms already operate on this model and with the added incentive customers preferring to rent newer models, this means that the equipment is often ''preemptively'' replaced before failures even occur.

The title text refers to {{w|Isaac Asimov}}'s science-fiction short story ''{{w|The Last Question}}'' ([http://imgur.com/gallery/9KWrH comic version]), where humanity asks, at different stages of its spatial and technological development, the same question to increasingly advanced computers: "How can the net amount of {{w|entropy}} of the universe be massively decreased?". At each point, the computer's answer is that it does not yet have sufficient data for a meaningful answer. Ultimately, the computers are all linked through hyperspace, outside the physical boundaries of the universe, and make up a single computing entity named AC which keeps pondering the question even as the {{w|heat death of the universe}} occurs and time and space cease to exist. When AC finally discovers the answer, since there is nobody left to report it to, it decides to demonstrate it and says "{{w|Let there be light|LET THERE BE LIGHT!}}", which are the first words said by God during the Creation, according to the {{w|Book of Genesis}}. Here, the title text implies that, as the universe died, AC no longer had a use for it as a physical support and, taking the comic's logic to the next extreme, chose to discard it and get a brand-new one instead of bothering to "fix" it by reversing its entropy. This short story was also referenced in [[1448: Question]].

This comic's concept of taking a real-world phenomenon and exaggerating it to levels currently considered implausible for comic effect closely mimics an earlier comic which describes progressively more "hardcore" programmers in [[378: Real Programmers]]. This comic might be related to [[1567: Kitchen Tips]] which suggests not throwing away your dishes but washing them.

==Transcript==
:[Zoom in on Hairbun holding her hand palm up in front of her taking to people off-panel right.]
:Hairbun: RAID controllers don't make sense at our scale; everything is redundant at higher levels. When a drive fails, we just throw away the whole machine.

:[In this frame-less panel it is revealed that Hairbun talked to Cueball and Ponytail who is looking her way.]
:Cueball: Machine? We throw away whole racks at a time.
:Ponytail: Yeah, who replaces ''one server''?

:[Hairy has appeared from the left and holds one hand palm up towards the other three where also Hairbun has turned towards him.]
:Hairy: We just replace whole rooms at once. At our scale, messing with racks isn't economical.
:Hairbun:  Wow.
:Cueball: Like Google!

:[Megan walks in from the left, and everyone including Hairy now looks towards her. Cueball has taken a hand up to his chin. The replies to Megan are written with clearly smaller font.]
:Megan: We don't have sprinklers or inert gas systems. When a datacenter catches fire, we just rope it off and rebuild one town over.
:Hairy: Makes sense.
:Cueball: I wonder if the rope is really necessary.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Hairy]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Hairbun]]
[[Category:Computers]]
[[Category:Fiction]]