The Navy’s newest warship is powered by Linux

http://arstechnica.com/information-technology/2013/10/the-navys-newest-warship-is-powered-by-linux/

by PLenz • 13 years ago

191 162 13 years ago

cweaver• 13 years ago

Does anyone know how those EMEs compare in size with existing control systems? They seem quite large for what I assume they do.

X45• 13 years ago

I don't know the exact measures, but does a D-Wave Quantum Computer fit into the EME? Here's a larger picture: http://www.wired.com/wiredenterprise/wp-content/uploads/2013...

Or they needed very heavy shielding, for whatever reason? I'm curious why that is too, does someone know it?

ChuckMcM2• 13 years ago

This will be interesting (it takes containerized data centers to an interesting place). Given that naval engagements seem to be either 'unsophisticated Somali pirate' level or 'super sonic ship-killer cruise missile' there isn't a whole lot of middle ground in terms of reaction space.

I can say this though, I'd love to see the insides of one of these ships.

gk12• 13 years ago

They look just about the same as ships in the current fleet. Much of the new tech is not easily recognizable, even from the inside. For example, high-tech materials, C4I systems, etc.

ChuckMcM2• 13 years ago

So living in Las Vegas in the 70's there was an amazing place called 'Buck's War Surplus' that had all sorts of stuff [1] end up there, it will be interesting if the self contained data center units do. Since they are designed to take "regular" gear instead of mil spec gear they could make for a heck of a doomsday data center backup :-)

[1] The top bubble dual 50 cal from a B25 Mitchell showed up once (demilitarized) and I could not convince my Dad to loan me the money to install it in my 1970 Pontiac Bonneville :-(

undoware• 13 years ago

Great -- now the fragment of code I wrote for the kernel make s me potentially party to killing.

The long-term ethics of producing open source are fascinating -- you know we're all pretty gross if the NRA is wrong, don't you? About X not killing people, people killing people. 'Cause we brought a whole lot of X, and gave it away, puffed with pride, to people who can name something a 'dreadnought' without it being weird.

nickff• 13 years ago

By that measure, one might be complicit in a bombing strike if the aluminum cans they recycle are used to build aircraft, missiles, or other weapons (, much like your code was recycled by the navy contractors).

If we live in a society where any measure of cooperation with others is subject to such a high level of scrutiny, we are all guilty of every moral indiscretion committed by anyone. Individual responsibility is almost a requirement for the complex and interdependent world in which we exist.

JonFish85• 13 years ago

Not to mention that if you pay taxes to a government that has a military presence anywhere you're much more directly supporting killing, if you want to look at it that way.

robin_reala• 13 years ago

Reminds me of JSON’s licence: https://news.ycombinator.com/item?id=4762035

camus2• 13 years ago

Yeah , FOSS projects should add "The Software shall be used for Good, not Evil." to their licenses ! though it is not clear how one would define evil ;)

krapp4• 13 years ago

And of course IBM's having to get a waiver because of what happened that one time they sold a ton of adding machines to the Nazis...

X45• 13 years ago

The container design is heavily inspired from Google's Datacenters. This will continue happening and cannot be prevented, even a new license for the Kernel prohibiting a military use won't help. Because they can fork an "old kernel" and continue their secret development on it. It's better to know what the government is doing rather than just trusting on a "license". We've been shown often enough in the past and present that people can't blindly trust a Government's actions and ethics.

Do the containers shield against strong EM fields? Otherwise an enemy could detonate a mini em-/atom-bomb close to the target, in order to destroy their operative computer systems. Is that the reason for the heavy metal casing? In that case they probably also used Fiber cables with the lastest known modulation techniques to get (n-)Terabit/s per container. Maybe they even have radiation shielding [1] to protect from inner and outer radiation. This beast doesn't look like it solely runs on diesel, but on an atom-reactor.

aaronem• 13 years ago

I doubt she has a nuclear plant, actually; there's a Raytheon paper [1] which spends some time talking about the need for fuel efficiency to maximize operational availability, which isn't often a concern for nuclear-powered ships whose rate of fuel "burn" is constant and whose refueling intervals are best measured in years.

[1] https://www.navalengineers.org/SiteCollectionDocuments/2010%...

drzaiusapelord• 13 years ago

Err, any nuclear attack be it "mini" or regular is provocation to nuclear war. The US won't sit back and watch the Chinese blast our navy to bits with airburst nuclear weapons causing EMP. More than likely the US would strike back with nukes.

You don't get to avoid the whole balance of power/MAD card because your nukes were used for EMP only.

protomyth2• 13 years ago

"Do the containers shield against strong EM fields?"

from article: Each EME has its own shock and vibration damping, power protection, water cooling systems, and electromagnetic shielding to prevent interference from the ship's radar and other big radio frequency emitters.

I would imagine that would include EMP given the modern threats and US Navy's general understatement of capabilities.

rtkwe2• 13 years ago

Straight from the article:

"Each EME has its own shock and vibration damping, power protection, water cooling systems, and electromagnetic shielding to prevent interference from the ship's radar and other big radio frequency emitters."

The military is no stranger to EM hardening their systems. They've been doing it since the cold war after all.

X45• 13 years ago

That's not your fault, but if you have a bug in there and the ship sips, can they sue you?

takluyver• 13 years ago

Most open source licenses explicitly say that the software is provided with no warranty. IANAL, but I think that's intended to prevent people suing you if they use your code and something goes wrong.

npsimons• 13 years ago

DoD employee here - maybe it's just me assuaging my conscience, but I always like to think that in the case of working on software for weapons systems, I've merely helped make them more accurate - I have absolutely no control over what they are aimed at, and that's a bigger problem than I can solve. To put it more succinctly: all Americans are responsible for the leaders they elect, and what they do.

These days, I'm fortunate enough to work on training sims for demining. I'd have to recommend that if you are really concerned about being a potential party to killing, don't worry about it - until you vote. Or maybe even write a letter or do some activism. But the last thing you should do is cripple the tools you make for others to use in some sort of ignoble bid to be moral. That's not moral, it's unprofessional.

rayiner2• 13 years ago

As someone who has done DOD work (though not on anything "pointy") I've never felt the need to justify myself in this way. Throughout history, countries have lived and died by the strength of their military.[1] America's global supremacy would not be possible without its military domination, and our standard of living would not be possible if we had to worry about falling under some other power's thumb. Also, while we're at it, we subsidize defense for nearly all the liberal democracies in the world. I feel quite positively about my contributions to all these things.

[1] The study of history is, to a first approximation, the study of war. I am not conceited enough to believe that my generation is the first one that is living outside of history.

DerpDerpDerp2• 13 years ago

But the last thing you should do is cripple the tools you make for others to use in some sort of ignoble bid to be moral. That's not moral, it's unprofessional.

I could just stop making tools.

I don't think I'm okay with making wars a clean, professional thing. It should be brutal and bloody and messy at every stage, so we can't isolate ourselves from what we're doing.

If you're making weapon systems and going "Well, I'm not responsible, I just helped make a technology" and the guy firing them is saying "Well, I'm just following orders and pressing some buttons, I'm not really killing them" and the guy in charge is saying "I'm just implementing what the politicians/people want" (depending on how high up the command), who exactly is left actually carrying the price of it?

No, I think I should do everything I can to make sure that we are forced to viscerally feel the terribleness of war when we decide to wage it - not pretend it's a video game.

archagon2• 13 years ago

Maybe there should be an open-source software license with a clause that prevents your inventions from being used in instruments of war and violence.

gpcz2• 13 years ago

Such a license would violate Clause 6 of the Open Source Definition (src: http://opensource.org/osd-annotated ), which states that you cannot restrict use based on fields of endeavor. Therefore, you could make the license, but you could not call it open-source.

wtbob2• 13 years ago

I'd be pretty annoyed if I couldn't use open source software to defend my home.

croikle• 13 years ago

One license offered for Phil Rogaway's OCB block-cipher mode explicitly prohibits military use. (although, as I read it, the military could use still open source implementations under the other license)

http://www.cs.ucdavis.edu/~rogaway/ocb/license.htm

vacri3• 13 years ago

No worse than a farmer whose produce gets sold further down the chain to the military, or the soup kitchen volunteer who doles out soup to a man who later murders someone.

wtbob2• 13 years ago

Great -- now the fragment of code I wrote for the kernel makes me potentially party to killing.

In much the same way that the food one grew might make one party to killing, should it nourish a killer, sure. But that's a bit of a dorm-room realisation: nothing any of us does can be wholly good or wholly evil; rather, we must each strive to do the most good and the least evil within our ability.

you know we're all pretty gross if the NRA is wrong, don't you?

And elephants are spherical if ducks are constructed of silicon and finely-shredded buts of the Rubaiyat. Fortunately, the NRA's not wrong: it's not the technology, but the people who wield it, which can be a problem.

celticjames• 13 years ago

"It should be noted that no ethically-trained software engineer would ever consent to write a DestroyBaghdad procedure. Basic professional ethics would instead require him to write a DestroyCity procedure, to which Baghdad could be given as a parameter. " -- Nathaniel Borenstein

gizmo686• 13 years ago

That is a horrible approach to take. Eventually you will end up with a DestroyCity, DestroyBuilding, DestroyBridge, ETC procedures. You should create a simple Destroy procedure that can take any valid target.

unfamiliar• 13 years ago

You're part of a system/society which depends on force to maintain its existence. If you don't like that fact and don't want to be part of that system, stop paying taxes and go live in the woods. After all, your tax money is contributing just as much as your source code to the military.

milliams• 13 years ago

The article seems to mention that they are running LynxOS, not Linux. Can anyone clarify?

richardwhiuk• 13 years ago

LynxOS is Linux compatible, which I suspect is where the deviation has come from.

disc2• 13 years ago

As I understand it, the DAPs run LynxOS, while the TSCEI networking and processing is done in Red Hat.

shavenwarthog2• 13 years ago

LynxOS is hard-real-time, unlike Linux, but is Linux-compatible.

http://en.wikipedia.org/wiki/LynxOS

Scramblejams2• 13 years ago

This made me wonder what the state of the art is in open source realtime operating systems these days. RTLinux is one of the options, but I've forgotten many of the rest by now. Anybody had any positive or negative experiences with any of the RT flavors?

Shish2k• 13 years ago

more than 235 equipment cabinets (racks) in total

I wonder what they're doing that needs that much processing power? Or is it that every part of every subsystem has a dedicated server assigned to it no matter how little power it needs, just to stop the possibility of interference?

morrad2• 13 years ago

Seeing as this is the military, I would guess that they have triple redundant systems for some things, but that still is a decent amount of computing power there.

X45• 13 years ago

Is the "James Kirk" part a joke, or is that the real name of Zumwalt's Captain? Sorry, if this looks blue-eyed, I can't tell that from sarcasm.

DannyBee• 13 years ago

I once interviewed a guy whose resume implied he played a large part in designing some of these redundant systems for carriers/whatever.

I asked him how he dealt with failover/etc, and said they used master election, and that it was guaranteed to work, and then proceeded to describe exactly a system guaranteed to fail. He had never heard of paxos, and when i described it to him, he was sure it wouldn't work.

ninjac0der• 13 years ago

I wonder if this has applications relevant to countries trying to ween from our technical infrastructure.

andor• 13 years ago

I wonder what they're doing that needs that much processing power?

Java EE?

protomyth2• 13 years ago

They are trying to find, track, and compute a shot at lots of things that can be very stealthy or go very, very fast. They would also like some redundancy since a server fail gets very costly.

FLUX-YOU• 13 years ago

It's a mission designed to run Crysis 1 at 60FPS. I hear rumors that if they reach 61, the full fury of an uncontrollable lens flare reaction takes place, so they can only do this mission in the Mariana Trench for safety reasons.

bane• 13 years ago

plus, being on a Navy ship gives them virtually unlimited water to use as a coolant for the overclocked systems.

ihsw• 13 years ago

It's probably a command & control vessel that does real-time stuff (flight/listening post telemetry, intelligence gathering).

robertfw• 13 years ago

We'll just have to cross our fingers that they don't run into any cylons...

More realistically, I wonder what the attack surface of a highly computerized, networked ship like this is? What kind of separation can you achieve between the layered networks - would there be systems that are essentially air gapped from one another?

sigzero• 13 years ago

"designed for stealth, survivability, and firepower"

I imagine that would take a bit. I also imagine there is a LOT of redundancy.

rtkwe2• 13 years ago

Traditionally they might have been air gapped but from the description of anyone being able to use any station that would not longer possible. They might run on isolated servers, almost definitely since the Armed forces are religious about separation of classified and non-classified systems and data. (This is one reason why sites hosting the Wikileaks and Snowden documents are banned from networks. If classified data, which the leaks still are despite being leaked, appears on an unclassified system there's hell to pay.)

As for the attack surface incoming communication is encrypted a lot these days which severely limits an attackers ability to even get a hook in the system to start with. They also probably isolate the communication systems from an other systems requiring users to input any order, eg vm000123 is running on the gun controllers station relaying firing authorization and targeting which is entered into vm0002020 which manages the gun systems.

mbreese• 13 years ago

From the article, it sounded like each of the systems was running on a stripped down Linux VM, so each of the stations would be logically isolated from each other, running in the same "data center".

kibwen• 13 years ago

"Almost all of the ship's internal communications are based on Voice Over IP (with the exception of a few old-school, sound-powered phones for emergency use)."

Interesting, I'd never heard of sound-powered phones before:

https://en.wikipedia.org/wiki/Sound-powered_telephone

cobrausn3• 13 years ago

Well, that brought back some memories. Shouting into sound powered phones over the din of the engine room of a submarine is one thing, but trying to actually hear what the other person is shouting back... it must be the audio equivalent of learning to read doctor's prescriptions.

michaelwww2• 13 years ago

Were you on a diesel boat? Because I was on a nuclear sub and it was pretty quiet and the sound powered phones worked great.

gk12• 13 years ago

I, too, had to shout into a sound-powered phone in the very center of a ship's plant. Often it was with the bridge crew. The bridge is very quiet at night, so the crew up there would almost whisper into the phone, completely oblivious to the fact that I can't hear a damn thing over the turbines.

mpyne5• 13 years ago

Ah yes, the 8-step method conducted in accordance with the Doctrine for Submarine Interior Communications Manual (w/ Change 1). Fun times, especially if you were the phone talker.

eru4• 13 years ago

Why don't they fit hand cranks to the sound powered phones to provide for some electricity?

blhack2• 13 years ago

Commander Adama is spinning in his grave over that one.

awongh• 13 years ago

It's almost a tin can and string!

jstalin• 13 years ago

I wonder what an EMP would do to it.

disc2• 13 years ago

Modern warships are designed for EMP threats. It's mentioned in MIL-STD-464.

X45• 13 years ago

wow, I didn't know that! That's really crazy.

stcredzero6• 13 years ago

Military spec processors are specially made to be "hardened" against that kind of thing. Back in the late 90's military spec Intel chips were almost one chip generation behind consumer cpus, but the packaging was considerably different.

EDIT: In the competition between EMP nuclear weapons and Faraday cages, Faraday cages win. They're fundamentally cheaper tech.

polskibus• 13 years ago

where's the source code though?

claudius2• 13 years ago

You get it when you buy one, I’d presume.

hrjet• 13 years ago

Which means every tax payer should have access to it?

outworlder• 13 years ago

Unless it is GPL 3 with it's anti-tivoization clause, you get nothing.

Either that, or we'd need a GPL 4 with an anti-warship clause.

TallGuyShort• 13 years ago

More accurately, you get it when one is distributed to you and you request it.

makerops• 13 years ago

Was curious as to who the ship was named after:

"As the coffin passed each SEAL, they slapped down the gold Trident each had removed from his own uniform and deeply embedded it into the wooden coffin. For nearly 30 minutes the slaps were audible from across the cemetery as nearly every SEAL on the West Coast repeated the act.[8]"

http://en.wikipedia.org/wiki/Michael_A._Monsoor

reustle• 13 years ago

And here is a picture of the coffin [1]

[1] http://storiesofusa.com/images/us-navy-seal-michael-monsoor-...

mrbill• 13 years ago

And a video of them doing so - start at 8:45. http://www.youtube.com/watch?v=CfK2BQCIIes

auctiontheory• 13 years ago

It's James "A." Kirk. Boo hiss. Source: http://www.public.navy.mil/surfor/ddg1000/Pages/bio1.aspx#.U...

njharman• 13 years ago

An improvement in OS choice over http://gcn.com/articles/1998/07/13/software-glitches-leave-n...

backprojection• 13 years ago

I don't know if my perspective is just so heavily biased or impractical at this point, but I'm almost embarrassed that my country's Navy would use windows for such a critical system.

anigbrowl3• 13 years ago

I always find this phrase 'powered by...' a bit sad when used in relation to computer software. I'm pretty sure the ship is powered by a large diesel engine or a small nuclear reactor. It's managed or controlled by Linux...well, technically via Linux but that's beside the point. A trivial objection, but I don't care for my news reporting to read like a breathless press release complete with meaningless marketing-speak.

rjohnk• 13 years ago

I get your point, but that's just semantics. You go down on the list of definitions in Webster and you could find that "power" means exactly what the Title eludes.

anigbrowl3• 13 years ago

I'm coming to the conclusion that when citing a dictionary or other reference work, the probability of an unforced language error in the same sentence asymptotically approaches 1.

saraid216• 13 years ago

But it's not actually Linux that's managing or controlling the ship. It's Linux that's managing or controlling the software that's actually managing or controlling the ship.

I mean, if we're getting into a semantic argument.

anigbrowl3• 13 years ago

Ultimately, ship is being managed/controlled by humans, for the time being. But I take your point, this is why I mentioned 'via Linux'.

lelandbatey• 13 years ago

Yes, we can only really accurately say:

    "Linux is playing a role of some significance in the latest 
    ship for the US Navy."

vacri3• 13 years ago

You could also argue the semantics that the ship is powered by its sailors. Without them, it's not going to go anywhere; it's their actions that are the root cause of moving the thing.

Kiro• 13 years ago

So what OS is the software that is controlling the ship?

LeChuck• 13 years ago

It's powered by two Rolls-Royce gas turbines, actually.

http://en.wikipedia.org/wiki/Rolls-Royce_Marine_Trent

ma2rten• 13 years ago

I would argue that it is the captain that is managing/controlling the ship.

jdubs2• 13 years ago

A few software licenses restrict the use of software in use of nuclear weapons & other WMD. I'm sure this vessel is capable of launching nuclear weapons, but it makes me wonder if the government will honor those license agreements or even if they were apart of the consideration.

azernik3• 13 years ago

Which licenses exactly? I've never seen such a clause, and I'm pretty sure it would be against the FSF's definition of Free Software, and definitely against the OSI's definition of Open Source.

btown• 13 years ago

I recall that there was a Java reference site that was highly ranked on Google that placed all of its examples under such a license.

claudius2• 13 years ago

While some software has such strange licenses, most ‘free’ software is truly free and e.g. Debian even makes it a strict requirement for inclusion that there are no restrictions on how software can be used.

So I’d say the question whether the USG will honour such licenses is somewhat moot, as there is plenty of software around without such restrictions.

a3n2• 13 years ago

Ah, but will they publish their nuke-enabling mods to GPL software?

antsar• 13 years ago

The CDS workstation uses common USB interfaces for its peripheral devices (such as trackballs and specialized button panels)

This could open up some interesting potential vulnerabilities, but I'm assuming/hoping that they've thought of that.

wslh• 13 years ago

Imagine a science fiction story where someone introduces a backdoor in the Linux kernel or in some known command...

VladRussian22• 13 years ago

first episode of [modern] Battlestar Galactica.

Amadou3• 13 years ago

Anybody remember the USS Yorktown? The one that ran Windows NT 4.0 and had the apocryphal story about blue-screening and having to be towed back to shore?

https://en.wikipedia.org/wiki/USS_Yorktown_%28CG-48%29#Smart...

wnevets2• 13 years ago

From your link:

In 3 August 1998 issue of Government Computer News, a retraction by DiGiorgio was published. He claims the reporter altered his statements, and insists that he did not claim the Yorktown was towed into Norfolk. GCN stands by its story.[7]

Atlantic Fleet officials also denied the towing, reporting that Yorktown was "dead in the water" for just 2 hours and 45 minutes.[6] Captain Richard Rushton, commanding officer of Yorktown at the time of the incident, also denied that the ship had to be towed back to port, stating that the ship returned under its own power.[8]

Even though the problem was caused by programming error in the Remote Data Base Manager application and not by problems with the operating system itself, criticism of operating system choice ensued. Ron Redman, deputy technical director of the Fleet Introduction Division of the Aegis Program Executive Office, said there have been numerous software failures associated with NT aboard the Yorktown.

stcredzero6• 13 years ago

I've also read that NT 4 servers on AEGIS cruisers once had to be rebooted weekly.

Amadou3• 13 years ago

From Merriam-Webster:

apocryphal: of doubtful authenticity

hackula1• 13 years ago

I can see it from my window as I type this over the Charleston Harbor :)

lispm• 13 years ago

Wonderful, just what the US needs: more weapons.

dhimes• 13 years ago

This is the year of the Linux warship.

Nux• 13 years ago

Guess it's not first time when Linux facilitates mass murder and misery, or of course, ahem national defense.

What a shame. GPL should have a clause "do no evil".

rosser• 13 years ago

The GPL will never have a "do no evil" clause. Such a thing is un-enforceable, and directly conflicts with "Freedom 0".

For example, the JSON license is deemed to be non-Free by the FSF because "The Software shall be used for Good, not Evil."

Source: https://www.gnu.org/licenses/license-list.html#JSON

vacri3• 13 years ago

Such a clause is trivial to get around, and is exactly how the US argues for its massive military budget: "This is for defense, not offense. Therefore good". Who do you then appeal to in order to stop them?

chatman• 13 years ago

Wow, what a surprise!!! Incredibly surprising, but you know what, even most mobile phones and most servers in the world are powered by Linux too!!

Jokes apart, almost any organization or commercial project out there which requires a new OS to be built from scratch prefer to use the Linux kernel.

ck2• 13 years ago

Hopefully it will reduce the cost, albeit slightly.

Why exactly do we need so many warships and aircraft carriers?

I mean what exactly are we doing with thirteen aircraft carriers that cost a small fortune to run?

rayiner2• 13 years ago

Because the ocean is big and we want to be able to dominate all the key areas of it.

grecy• 13 years ago

Need to find a way to use up the excess produced in this world. You could just dig big ditches in the ground and dump lots of new goods in there, but the general public wouldn't get behind that the same way they do a war.

mpyne5• 13 years ago

10 aircraft carriers, not 13 (though it will be 11 again in a couple years).

The reason extends from matters of strategic planning though. Carriers provide "power projection" capabilities to about 90% of the populated earth.

Power projection is inherently needed for the DoD planning assumptions (which are now, IIRC, to be able to fight and win 1 major conflict while responding to at least one other military contigency). The expected military requirements for those worst-case plans probably involve having at least 3-4 carriers.

However, this is a worst case plan, which means those 3-4 carriers must be available, and on station (or nearby to respond), at all times.

When you include the requirement to maintain/repair/overhaul the vessels, handle training periods for embarked aircrew, training and certification workup periods for the embarked ship's crew, you quickly end up multiplying the ship count you need by at least 3-4.

In this case when they crunched the number I believe that they came to 9-10 to handle defense requirements. And then Congress told them to keep an 11th carrier anyways...

Scramblejams2• 13 years ago

mpyne and rayiner have hit all the high points, but if you're interested there's more detail here:

http://www.forbes.com/sites/quora/2012/07/17/why-does-the-un...

mpyne5• 13 years ago

The Navy has actually used Linux within warships for awhile now (via its defense contractors). The boat I served on a few years ago used Linux for at least two different subsystems. And before Linux they've used UNIX so it's not as if the Navy is completely new to all this.

chris_wot3• 13 years ago

To hell with Linux, the US Military use CORBA?

platz• 13 years ago

That's the real story here. The military has control of the allowed corba implementations so they don't suffer from different runtimes, and get all the typed benefits and speed benefits.

FrojoS• 13 years ago

I once heard that the Navy has a electronics phobia and relies as much as possible on mechanical and physical human control because EMP (e.g. du atomic bombs) are such a big thread. Maybe this is untrue or only true for key vessels like air craft carries. Does anyone know?

INTPenis• 13 years ago

Well it's more likely a mix of both. That is to say, if your computer crashes you should always have a manual backup.

mpyne5• 13 years ago

I wouldn't say a phobia, as much as an acknowledgment that historical experience has shown that electrical-type facilities are the most susceptible to damage, and that the conversion from analog electrical to digital electronic didn't always help matters.

I've served on a ship where we had to keep a "fake" target entered into the fire control system at all times, since it would crash if the last target was dropped. That system was our only interface to the torpedoes, so in that scenario we'd be left in the situation of having to wait minutes for the system to reboot before we could launch weapons again. Peacetime or not, it's not a good feeling.

Top all of that with the fact that we have to survive damage from accidents and casualties and not just battle damage. E.g. what happens if a fire breaks out in the port turbine generator and fries the connector wires to the solenoid for an important valve needed to control ship's list and trim? Without the possibility of manual backups we'd possibly be in for a very bad time.

The Navy has a lot of experience with how the oceans and the enemy will conspire against a ship. However well you design your circuits, it's still better to have something available which always Just Works.

tytso• 13 years ago

The Zumwalt is using Real-Time Java, using a JVM from IBM that has an incremental GC with real-time guarantees (unlike the real-time Java spec, which essentially works by disabling the GC for real-time threads, so their NonHeapRealTime threads were essentially an architected memory leak). IBM's Real-Time Java, with their real-time Metronome GC, is running on real-time Linux, for which I was the tech lead at the IBM Linux Technology Center.

It was a fun project; since we were able to use the real-time Linux code base which Ingo Molnar and Stephen Rostedt worked on upstream, we spent most of our time stablizing the patches, and fed quite a few patches back upstream to get it into a production-ready state. Anyway, we had 50 microsecond interrupt and scheduler latency using real-time Linux, which allowed millisecond level real-time guarantees using garbage collected java threads.

VladRussian22• 13 years ago

which allowed millisecond level real-time guarantees using garbage collected java threads.

an anti-ship missile at 2 Mach would move 0.7m during an ms and it wouldn't be a lateral move - sounds like Java has reached the level of getting into fire control systems :)

The Navy’s newest warship is powered by Linux

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