Comair System Crashes; Passengers Stranded

Broerman writes "30,000 people have had their flights cancelled by Comair this weekend thanks to a computer system shutdown. It appears that due to weather and other problems that flights began to be cancelled on Thursday and the backlog choked the system. 1,100 flights have been cancelled so far, including all flights through 12/26. Does anyone know what platform their system was based on? What kind of system just totally crashes? The official statement is that 'There was a cumulative effect with the canceled flights and trying to get crew assigned that caused the system to be overwhelmed.' It seems highly improbable that a system would crash because it had too many reservations. The system should only be able to hold as many reservations as it has flights/seats. It would seem that it's more likely that the system was overloaded with use and that caused a meltdown. When you add in the problems experienced by US Airways, this hasn't been a Merry Christmas for many."

Fire away!

Anybody know what they were running? I'd like to see this flamewar get started as soon as possible.

Re:Fire away!

There recently was a big card problem here, in Europe.
It did not come from a peculiar OS but just because a partition got filled by index tablespace extents.
So, it could just be that they ran out of place and it froze the whole application.

Re:Fire away!

Interesting...

Job postings might give some insight: Comair, Inc. jobs [yahoo.com] into what they are using.

Re:Fire away!

Someone from Comair (who shall remain anonymous) provided me with some details whch people here would be interested in:

The computer system in question runs AIX. The box itself is still up and running just fine; this is purely an application error. This application was not written in-house at Comair, but by another large aerospace company -- SBS (http://www.sbsint.com/ [sbsint.com], owned by Boeing.) This bit of software does not use an external database, it tracks everything itself. It is a dedicated system responsible only for flight crew assignments. (The blather in the original submission about passenger reservations is way off-base. Those functions are handled by a completely different system.)

The great majority of Comair's traffic flows through the midwest, and the central base of operations is in Cincinnati. The midwest was hit by a major snowstorm this week, causing many, many crew reassignments. It appears right now that the application in question has a hard limit of 32,000 changes per month (ouch). Consider that Comair runs 1,100 flights a day and there are usually 3 crew members on each aircraft. A big storm like this can cause problems for days after the snow stops falling. That's a whole lot of crew changes.

In Comair's defense, this has never happened before and is unlikely to happen again. The crew system was already on the chopping block long before this incident, with its replacement scheduled to go live in January. If this freak storm had happened a month later, this likely never would have occurred.

Re:Fire away!

Just to be absolutely clear: I've only ever communicated with this person on-line, and I can't verify who they are in real life or that they actually work for Comair. It seemed credible though, and it seemed worth posting to de-bunk the slashdot knee-jerk reaction of blaming Microsoft. To me, an application using a 16-bit integer for something seems like a very likely explanation.

Yep, you are right!

Your statements are accurate.

I was a unix sys admin there, but left for greener pastures during the dot-com craze. The non-redundant hardware at the time ran AIX, and had a great support contract from IBM. The SBS application however, always had monthly issues, at least at that airline. They were looking for a replacement then, and I'm not suprised they still haven't replaced it.

Re:Fire away!

If it was the crew scheduling system, and it was SBS's Maestro Crew scheduling system, I can fill in some details.

Maestro is delivered on AIX, uses a rather old version of Informix for it's database, and is tied together using the TUXEDO TP monitor from BEA.

The business logic is written in C, and abstracted away using Tuxedo.

In the case of a major schedule disruption, this program isn't responsible for "solving" the problem, but is responsible as being the system of record for holding the new crew schedule.

My guess is that the changes to the crew schedule were large enough that some piece of the system was overwhelmed. ( For example, a transaction that was too large and overran the rollback buffers in Informix ).

Without the system of record in place, a manual process would be very difficult. You would have to figure out:

• Which crews where in which locations
• What aircraft each crew member was qualified on.
• How long they had flown already that day. ( Legalities about how much time you can fly before you need mandatory rest )
• Which routes to send those crews on
• How to get the crews back to a specific city to run the next day's schedule

Of course, any mistakes you made doing this manually would overflow into other systems. For example, you might send an aircraft that's due maintenance to a city with no maintenance facilities.

Also, for those that were critical of the system not being highly availble...this doesn't sound like the kind of problem that HACMP and replicated databases would have helped. The hot standby would have choked at the exact same point.

Re:Fire away!

No. It is the version of SBS that pre-dated Maestro. It was brought into Comair in the early 1980's. It's written in FORTRAN and uses whatever record managment system that came with the compiler.

As such it used some very interesting data representations. For example, it tracked time using julian minutes. There are 44640 minutes in a 31 day month. That's small enough to fit in a 16-bit unsigned variable. This approach, nearly taboo by modern standards, was a God-send during Y2K. The system never needed to know what year it was. It became the running wisecrack, "You can't have a Y2K problem if you don't have a 'Y'".

The Aircraft to Flight assignments is another system [sita.aero], but the two share information.

Re:Fire away!

just to give you an idea, here is the applicable FAA reg for crew scheduling, and the pilots contract may have additional terms that must be met.

121.471 Flight time limitations and rest requirements: All flight crewmembers.
top

(a) No certificate holder conducting domestic operations may schedule any flight crewmember and no flight crewmember may accept an assignment for flight time in scheduled air transportation or in other commercial flying if that crewmember's total flight time in all commercial flying will exceed--

(1) 1,000 hours in any calendar year;

(2) 100 hours in any calendar month;

(3) 30 hours in any 7 consecutive days;

(4) 8 hours between required rest periods.

(b) Except as provided in paragraph (c) of this section, no certificate holder conducting domestic operations may schedule a flight crewmember and no flight crewmember may accept an assignment for flight time during the 24 consecutive hours preceding the scheduled completion of any flight segment without a scheduled rest period during that 24 hours of at least the following:

(1) 9 consecutive hours of rest for less than 8 hours of scheduled flight time.

(2) 10 consecutive hours of rest for 8 or more but less than 9 hours of scheduled flight time.

(3) 11 consecutive hours of rest for 9 or more hours of scheduled flight time.

(c) A certificate holder may schedule a flight crewmember for less than the rest required in paragraph (b) of this section or may reduce a scheduled rest under the following conditions:

(1) A rest required under paragraph (b)(1) of this section may be scheduled for or reduced to a minimum of 8 hours if the flight crewmember is given a rest period of at least 10 hours that must begin no later than 24 hours after the commencement of the reduced rest period.

(2) A rest required under paragraph (b)(2) of this section may be scheduled for or reduced to a minimum of 8 hours if the flight crewmember is given a rest period of at least 11 hours that must begin no later than 24 hours after the commencement of the reduced rest period.

(3) A rest required under paragraph (b)(3) of this section may be scheduled for or reduced to a minimum of 9 hours if the flight crewmember is given a rest period of at least 12 hours that must begin no later than 24 hours after the commencement of the reduced rest period.

(4) No certificate holder may assign, nor may any flight crewmember perform any flight time with the certificate holder unless the flight crewmember has had at least the minimum rest required under this paragraph.

(d) Each certificate holder conducting domestic operations shall relieve each flight crewmember engaged in scheduled air transportation from all further duty for at least 24 consecutive hours during any 7 consecutive days.

(e) No certificate holder conducting domestic operations may assign any flight crewmember and no flight crewmember may accept assignment to any duty with the air carrier during any required rest period.

(f) Time spent in transportation, not local in character, that a certificate holder requires of a flight crewmember and provides to transport the crewmember to an airport at which he is to serve on a flight as a crewmember, or from an airport at which he was relieved from duty to return to his home station, is not considered part of a rest period.

(g) A flight crewmember is not considered to be scheduled for flight time in excess of flight time limitations if the flights to which he is assigned are scheduled and normally terminate within the limitations, but due to circumstances beyond the control of the certificate holder (such as adverse weather conditions), are not at the time of departure expected to reach their destination within the scheduled time.

Happens all the time...

When I lived in Chicago, they would lose their radar system on what seemed like a strong wind. And I got stuck in Denver overnight once because the computer system they use to calculate the weight of departing flights crashed. I have a feeling these kinds of crashes are much more common than most people think.

Re:Happens all the time...

I have a lot of friends working at a large airline.

Yes, but it is mostly recoverable. The heavy iron handles things like backend reservations, checkin and cargo. Smaller systems handle things like weight/balance and fuel and PCs are typically used for the front-ends.

Weight/balance calcs can be done more or less by hand if necessary, however a larger fuel margin is needed. Checkin can be done by hand (you have seen those sticky label systems). However to lose reservations is a major problem.

Re:Happens all the time...

From looking at the various terminals that the airline people use, I suspect that most of those airline systems are held together with duct tape and library paste and no one really understands how the whole system works anymore. We see that a lot in non-IT industries (And a few IT ones, too.) Of course, the folks using the IBM ones are not ever supposed to go down...

I moonlighted as an AS/400 operator for a cruise line for a while. We had the system go down once because the janitor turned off the air conditioner in the closet the AS/400 lived in. They didn't dedicate a more secure facility for the computer because the computer wasn't demonstrably central to how the company made money. Turns out they couldn't launch a ship without it. Oops. I suspect that mentality is also prevalent throughout the non-IT industries. They don't know how important their computers are to their business models until those computers die on them.

Re:Happens all the time...

I used to work with a guy who at one time was an HP3000 operator back when those things were as big as your average washer/dryer combo. His shop had about a dozen of these things, and one night he and a buddy were playing frizbee with the circular write-protect rings that were used on the reel-to-reel tape drives.

Sure enough, his buddy whipped one at his head, and as he ducked out of the way, he fell back and by accident hit the power switch located on the back of one of the HP3000's. In an instant, all the ticket terminals for one airline (I can't recall which one) at O'Hare airport went down, prompting a frantic call from VP's wondering what disaster had struck. So who knows what could have happened this time around...

Official my arse...

Sounds like my Mother wrote the official statement. A techy would never report something in that way.

Besides, it's pretty obvious their OS wasn't digitally signed. :p

System Tracked Crew Location, Not Reservations

Of course, a techie didn't write the PR release. Who in their right mind would let a techie anywhere near a PR release?

BTW, Comair, a Delta feeder headquartered outside Cincinnati, says the system that crashed was used to monitor crew locations and track working hours to ensure no one went over the legal maximum. Comair says the system crashed as a result of massive crew rescheduling following a record snow in their service area on Wednesday. There is no backup.

Re:System Tracked Crew Location, Not Reservations

You know, I have my OWN reservations about flying on an airline when they have no backups and can't keep their computers from crashing. Whats to keep their planes in the air?

The last thing I want to hear at 30k feet is that my current flight has been cancelled...

Re:System Tracked Crew Location, Not Reservations

You know, I have my OWN reservations about flying on an airline when they have no backups and can't keep their computers from crashing. Whats to keep their planes in the air?

The Bernoulli Principle [fiu.edu]. And I don't think computers crashing are going to affect it. This isn't the Matrix, after all.

Someone's gotta say it...

Yep, it was Windows XP. ;)

I don't know. Frankly, it has less to do with the platform than the custom software that runs on it.

Re:Someone's gotta say it...

You would think so. The IT Director is respsonsible for making sure everything IT works. Not to do it himself, but to make sure it is done and done right. I can't see how someone can argue with that. Even if it IS the janitor unplugging the UPS to plug in a floor buffer.

Whether it is the cooling system for the computers, the operating system, the applications or simple hardware issues, it HAS to be the IT Director's responsibility. I mean, who the hell else?

Re:Someone's gotta say it...

Occasionally, however, the head IT guy gets over-ridden by management or by available finances. I've been there, saying "we need to spend money on this" and having to make do with much less money, or even with a cut in funding. You need to document the problem in advance to cover your ass, and get it in print and saved offsite to protect yourself from that kind of mistake. I've done that, too. It helped protect me from a nasty lawsuit because I demonstrated where I had told a consulting client, in print, when the systems would start failing and the resulting legal liabilities, and gotten it signed by the company notary.

Bringing the /. effect to the weary masses.

Linking to their home page will surely help the situation..

My theory?

The janitor pulled out the plug for the mainframe and used it to drive is floor polisher..

Simon.

Re:My theory?

BOFH excuse #38: secretary plugged hairdryer into UPS.

That is where you got the idea for that post, right?

Re:My theory?

Probably not. It's an old story (quickly retold):

Army base computer going down every night. So the grunt in charge of it stayed the night to see what was happening. When the computers went down, he heard the hum of the floor buffer.

The janitor had plugged his floor buffer into the same power as the computers and it caused the crashes. It was quickly fixed by telling the janitor to not do that and putting locking covers on the power outlets.

But they dreaded telling the base commander what the issue was. So they told him it was "a buffer problem."

Re:My theory?

A friend was sysadmin at a manufacturing plant, and the janitor kept plugging into the power conditioned sockets with a very large, power-hungry floor polisher. He was actually blowing power supplies. Every one cost several thousand dollars in service calls to replace the power supply and downtime.

My friend put "COMPUTER USE ONLY" stickers OVER the power-conditioned sockets. The janitor ripped them off to plug in, and blew another power supply.

My friend finally confronted the janitor, who was a really obstinate PITA. He stood there and said "Yeah, I did it, and I'm gonna keep doing it, and I don't give a damn about you or your fu*kin' computers."

This was a automotive union shop, very difficult to get people fired.

But, in a show of karma rarely witnessed by mortals, the VP of the division was standing within earshot but out of sight. When the janitor finished saying he didn't give a damn that he was costing the company $10,000 a week because he was too lazy to go get an extension cord, the VP walked around the corner and said hi. I don't know whether the guy ran to his car or the VP kicked his ass right over the top of it.

stating the obvious

"Does anyone know what platform their system was based on? What kind of system just totally crashes?"

A stab in the dark here but I'm assuming a system without foresight and redundancy?

It's obvouis...

What kind of system just totally crashes?

Oh come on...
That doesn't need answering.

Software.

I blame the software. Sounds like a more likely culprit than the OS, even if it is Windows.

It was running on SCO Unix...

They obviously didn't take mcbride's "license or we will have you shut down" threats seriously enough.

blaming the system can backfire

It's not the OS, it's the people behind who's to blame. Yes, stupidity and MSW often go together but in a few years one will probably occasionally see a massive linux outage due to... similarly stupid people.

Scalability and Twelve Step TrustABLE IT

Sounds like Comair could have used a little virtualized scalability and third party audited builds.
See Twelve Step TrustABLE IT : VLSBs in VDNZs From TBAs [blogspot.com].
and also The ActiveGrid(TM) Grid Application Server [activegrid.com] and Grid Computing [google.com] in general.

Re:Scalability and Twelve Step TrustABLE IT

No, its more difficult in the airline industry. The system by default tries to keep as many planes in the air earning money as possible. If you have an outage which disrupts this choreography, there is a tremendous knock-on effect as passengers/urgent cargo must be rebooked.

I have seen the major hub for an airline closed because of snow for just a couple of hours in the early morning, but the resulting chaos of rescheduling/rebooking caused the reservations system to crash after just a few minutes of uptime. The same would keep happening after restarts.

It is normal to test system up to several times normal load, but they were seeing peaks at over 100x. The old, 3270 emulator based system would have slowly got through it but the newer system died.

This is getting a little to common for them.

Back on May 1st of this year Delta's internal traffic monitoring system grounded them worldwide when it was hit by a worm (forget which one). Yours truly was flying that day. I spent 7 hours on a runway in Cleveland. (Talk about adding insult to injury.) Comair is a regional carrier of Detla's. I wonder who handles Delta's IT needs?

From old information...

According to this article [written in 1995] [cio.com], Dell and AT&T created a new company called TransQuest Information Solutions.

This article [20minutesfromhome.com] outlines how this joint venture re-vamped Delta's IT systems (again remember, this is 1995):

During 1995 and 1996, TransQuest reengineered Delta's systems to migrate them from Hitachi mainframes running Natural, Adabas, and DB2 to an open systems environment. The new systems are written in C++ and access Sybase databases of reusable and distributed objects. The systems run primarily on Sun, HP and AT&T servers under UNIX with clients running under UNIX, MS-DOS, and Windows. The clients are connected to the servers over high bandwidth TCP/IP frame relay networks.

Job titles for the company's 1,100 computer professionals include Systems Engineer and Software Engineer 1 through 8. Staff members recently developed an aircraft weight balance system that can be accessed by pilots to determine how luggage and fuel have been distributed within the aircraft for balance during a flight. This system was developed in C++ on AT&T and HP UNIX servers and will be available on 40,000 devices to 2,000 users.

The trail runs dry here, job postings stopped around 2001.

Which really raises suspicions that all the code is written and maintained offshore. The question now becomes who is handling this for Delta.

One of Tata's spinoffs, Airline Financial Support Services [airlinefinancial.com], is described as

"an example of an external service provider that handles a wide range of back-office functions for the airlines. AFS handles sales, refund, traffic and cargo; performs fare audits; manages yields and revenues by performing departure and post-departure processing checks; books crews; deals with overbooked flights and wait-lists; adminsters frequent flyer programs; draws up flight navigation charts; such as landing or route facility charts; and provides customer care." This according to ebstrategy.com [ebstrategy.com]

Wipro handles some of Delta's inbound reservation calls in India and the Phillipines. [wipro.com]

In conclusion, it would appear that either Tata's AFS arm or Wipro do the IT for Delta airlines.

Travel tip

FAA's Rule 240 says that if your flight gets canceled for any reason other than weather, the airline has to get you on the next available flight to your destination, regardless of carrier. So if you're stuck in an airport bar reading this article go talk to your airline!

Re:Travel tip

From: http://www.fly.faa.gov/FAQ/faq.html

The term "Rule 240" refers to a rule that existed before airline deregulation. There is no longer an actual Rule 240. The term, as it is now used, refers to each airlines "conditions of carriage" policy. You would need to contact the airlines to obtain this.

Failure due to inability/unwillingness to test/QA

It is not easy to do real world extreme situation testing on large systems, but I wish people would at least try.

It is fun to say Windows, blah, blah but given the number of buffer overflow problems found in programs/packages on all platforms, I would say that many programmers of every stripe severely underestimate the real world range/type/size of data their programs will encounter when in non-typical situations.

To whoever wrote/maintains/admins this software:Global "climate change" means weather "events" will be more frequent and more exteme in coming years, another terrorist event on US soil may cause days of air travel disruption. Please "refactor" your shit with those things in mind. You're on the East Coast and Midwest for god's sake you're going to get storms that will shut down regions for days at a time. What happens when the FAA finds some issue with an aircraft part or maint. procedure and grounds your whole damn fleet to have it fixed.

Read the code, Luke (episode II)

Somewhere deep in the code is a comment that says:

// I don't need to check for this condition because
// my asshole manager Steve Johnson says it'll
// never happen


{friggin' slash - When I say plain old text, I mean plain old text!}

BUG!

Now, I could be wrong, but I heard from a lot of people that it is the year 2005 bug... How did we not see this come?

Platform and software?

This [eclipse.co.za] and this [microsoft.com] might offer a clue.

But management saved 13.7% by hiring H1-Visas

Too bad the airline will go bust because of this. But then all airlines lose are loosing billions except for Southwest.

Crew assigment is a hard problem

'There was a cumulative effect with the canceled flights and trying to get crew assigned that caused the system to be overwhelmed.'

I am only trying to make sense out of the above comment from the official statement above.

Crew assigment is a hard problem, it is usually an MILP (Mixed Interger Linear Programming) [anl.gov].

Such problems may be very hard to solve in reasonable time. Maybe (I'm shooting in the dark here) the first delays made the crew assigment problems grow too large for being solved in reasonable time.This would generate a snow ball effect as the assimgment problems would keep on growing maing the system "crash".

We may never know what really happened but this would be a nice example for my classes :-)

Re:Crew assigment is a hard problem

It's far harder than that alone since you also have to get the aircraft back to the right city (many are in the wrong city due to airport shutdowns due to the weather). Obviously you want to optimize the number of passengers carried along for those flights, but at the same time you'll be "burning" allowed worktime for the crew.

Even worse the crew and aircraft are independent variables. Obviously you need a crew to operate a flight, but the crew may end up in the "wrong" city for the usual schedule. It may be better to leave a plane on the ground and fly its crew "deadhead" to the "right" city than to have them fly a load of passengers to the "wrong" city.

There are reasonably efficient algorithms to solve these problems, but we spent most of my entire second-semester graduate-level algorithms class studying them (network flows). The algorithms most developers would come up (including me after a decade of experience and graduate-level algorithm class) are extremely inefficient and scale horribly.

The bottom line is that it's easy to imagine a system that has no problem with pertubations from the regular schedule but is totally overwhelmed when starting from scratch. I hope the bean counter who saved the company a few bucks by insisting on far more modest hardware gets canned for his costly lack of foresight, but we all know that IT will catch the heat.

Can anyone say...

...slashdotted reservations?

30,000?

30,000 passengers? Getting dangerously close to an integer overflow there.

Re:30,000?

"30,000 passengers? Getting dangerously close to an integer overflow there."

That is not a bug but an accurate model of reality. When you strand 32,768 passengers, they will turn negative.

Y2K

With the amount of Y2K 'fixes' I have seen around, (and some of them very dubious), I wouldn't be at all suprised if it was a Y2K problem. Looks like someone didn't have all their test cases written down properly and/or didn't test properly and/or tried to 'fix' the problem.

I don't know about their internal system...

As a preliminary finding that may or may not give us a clue as to what the internet system was running, Netcraft reports that www.comair.com is running Apache on HP-UX.
So don't assume that the internal system was Windows just yet. Then again, don't assume that it wasn't.

whole story?

This comair story is all I'm seeing getting press. I think its a lot bigger than that.
My sister flew Delta on Dec 23rd from Detriot to Atlanta. Plane was 2 hours late, but no big thing. Waited 5 hours for her luggage, with no dice. By the time we got in line for luggage services, there were at least 600 people in the line already.
Talking to other passengers from 10+ different flights from different cities, no one got their luggage that night. Apparently, it wasn't just Atlanta - the local news in Tampa and Detroit had segments on how the airports had taken over parts of taxiways to sort through seas of bags that didn't make it on to planes.
It's been 2 days, and Delta has no idea where the stuff from that flight is. I'm guessing it isn't just Comair that got hit by some computer problems.

Jerry
http://www.syslog.org/ [syslog.org]

Re:whole story?

Personally I think that Delta was being a bunch of assholes about the whole thing...

Seeing that my 7pm flight was cancelled for the 23rd I spent 20 minutes redialing from two different phones until I got past a busy signal. After 50 minutes on hold I got through to a representative who scheduled me for the 24th's 7pm flight. I spent the rest of the time rearranging time off from work, the dog's time to be spent at the kennel, car rental stuff, and phone calls to my fiance who would meet me at the airport, and to family we were supposed to see.

At 7am on the 24th the flight was already cancelled. At this point I didn't give a shit anymore. Delta was saying I would have to use my tickets by the 15th of January because "it wasn't their fault". I knew it wasn't the fucking weather down there as plenty of people were saying it was fine in the area. So I call again and get through after redialing for 65 minutes. I get through to a rep after 50 more minutes in queue. She tells me she can't do anything but schedule me for the 25th at 7pm so I'd have to get in queue for the reissue desk. Fine...

After 2 hours and 11 minutes in queue (with no hold music or sound for that matter) someone calls on my home line at 5:15pm from Delta to tell me my 7pm flight is cancelled (cute, I would have been at the airport by then). I tell that rep to get me into the reissue queue as I've been on hold with them for 2 hours.

I finally get through and tell them I want my money back. They tell me I need to speak to customer service. After waiting on hold (with the reissue rep) for 25 minutes the reissue rep offers to refund my money.

We can't fly out for New Years as the kennel is booked and I'd feel horrible asking someone to watch our dog in our house for me than 1 night. So basically we have to wait quite some time to fly down there again.

It was a little bit of a pain in the ass to wait on hold and be jerked around for two days for something that was their fault when they continually claimed wasn't. BAD WAY TO TRY AND PLEASE A CUSTOMER.

Thanks for ruining our Christmas.

Not surprising, coming from Comair

Some of my co-workers are on contract developing Java software for Comair.

Comair are very tied to particular systems, and don't want to change even when the developers have pointed out problems. Case in point: a J2EE-based employee portal, based on Novell exteNd (Novell Portal Service) and a one-way HPUX server. NPS runs in Tomcat, which is servicing requests (via mod_jk) through Apache. No other application shares the machine, and Comair will only consider vertical scaling, not horizontal.

The application creates at least two threads per connection, and when the thread count goes beyond a relatively low threshold (between 300 and 400), Tomcat deadlocks. It's not because they're running out of space in the allocated JVM heap, and they've tuned mod_jk to allow for heavy load. The current solution is to restart Tomcat when the system locks up.

Novell's support has been less than stellar, so the Java contracting group was informally asked what to do. We had all kinds of useful suggestions, from dumping NPS for another portal implementation, to creating custom thread-pools, to using JDK 1.4 new I/O and a minimally-threaded design, and even using round-robin DNS and a group of independent portal servers to share the load. Comair are wedded to particular minimal cost solutions, however, and it shows.

At least when the portal crashes, it only impacts employees and not passengers.

I'm surprised

that in the name of sensationalism reporters haven't said, "terrorism is probably not to blame but the Dept. of Homeland Security is looking into it." It seems that after Sep. 11th, the news wants to try to connect everything even remotely bad with terrorism, and of course the Dept. of Homeland Security encourages them by using as vague of language as possible. Are people that easily frightened?

Re:I'm surprised

It seems that after Sep. 11th, the news wants to try to connect everything even remotely bad with terrorism

What else do they have to do? They've got this huge ass budget, all those people watching a lot of honest citizens. It was 10 years between the first attempt on the world trade center and the second. We've built and paid for this entire monster agency for an event that might be 10 or 15 years away. What are they going to do in the meantime? Grope women at the airport. They have to do something to justify their existence, Otherwise we'd have admit we over-reacted to 9-11.

It's obvious what happened

http://home.hccnet.nl/jaap.kranenburg/fun/xx/image s/fun20020415.jpg [hccnet.nl]

Exactly

Computers don't freak out or get depressed when work piles up. Backlogs mean nothing; they just keep processing one piece at a time until the pieces run out. I think someone was speaking imprecisely.

I suppose that the system *could* have been built with a rule to detect that the results are becoming more and more untimely, and at some point just say "TILT!" and deliberately exit. I can't imagine why, though; getting there late is better than sitting in the terminal forever.

No manual process?

WTF can't they do it manually? It's just keeping track of seats on planes for fsck's sake. Sure, they may not be able to accomodate everyone right away, but they could certainly do better than "nobody can fly at all because our computer system crashed". If a restaurant loses their computer, they don't stop admitting people. They just go back to paper orders/receipts.

seen it before

It appears that due to weather and other problems that flights began to be cancelled on Thursday and the backlog choked the system. 1,100 flights have been cancelled so far, including all flights through 12/26. Does anyone know what platform their system was based on? What kind of system just totally crashes?

Sounds like Diebold may have been contracted for the job.

I'd like to know

Not just the database platform and front end but who built it. This just has E-D-S stamped all over it. Everybody has a system go down once in a while, but it just seems like EDS has had more than their share.

This is a worst case scenario for a system of that nature because of so many dependent calculations and calls to other systems. It takes more than just having a plane and a crew...which is a lot of work all by itself. It has to have a gate and connecting flights. Then multiply all that by 30,000 people, roughly 120 plane loads, and complicate it by some airports being closed. I bet you could actually watch the lights get dimmer in the server room. Still when you know the potential peak demand you have reserve capacity. Slow is okay, stop is unacceptable.

Bailout

After 9/11, pretty much all of the domestic airlines were bailed out by the government to keep them from going poof (except for Southwest and a couple of others, who didn't have their heads up their asses). So I just want to know how long it will take this Delta affiliate to plead for money. That not only has it screwed over all of those passengers, the taxpayers will collectively pay for it.

Scare thought

Some company refuse to do a complete system over haul. They just keep patching and upgrading. Their decade old software.

I did a little researdh Conair was made Y2k compliant with only mirror changes.
http://budgettravel.about.com/library/weekly/aa101 599.htm [about.com] What i am saying is the software could be a couple decade old and be a rats nest of code. Kobold anyone?

Southwest refuses to drink the Kool-aid

This computer problem of Comair's just demonstrates how unworkable the hub-and-spoke system of flight scheduling is. It's a flawed concept, foisted on a naive public by an industry locked in some sort of mass psychosis. In the pursuit of minor economies of scale, the big airlines treat their passengers like packages (hey! it works for Fedex, and their cargo can't even walk itself to the next gate...), treat airport runways and air traffic controllers like unlimited resources, and waste vast amounts of jet fuel. The fact that Southwest Airlines (which does not use a hub-and-spoke scheduling system) is profitable, and the rest of our major airlines are either in, just out of, or about to go into, bankruptcy doesn't seem to dent their thick skulls.

I have watched the operation at Atlanta for over 21 years, and I've seen how cutthroat the competition for a major hub is, but it feels like watching two dogs fight over two bones--you can't tell if they're fighting out of greed or stupidity. Southwest doesn't even fly into Atlanta--they know that only a pyrrhic victory would be possible under those circumstances. Management at the other airlines has been criminally incompetent ever since airline deregulation, but it's the passengers, employees and shareholders who pay the penalty time and again.

Re:Southwest refuses to drink the Kool-aid

It's isn't that easy, for the longest time Southwest was the hardest to book a flight for because they had no web system that could figure out it's route system (only 5 years later they just released one). Up about about July of this year to book a web flight you needed a route map and schedule to figure out what cities you had to go throuh if there was no direct flight option.

The hub-spoke system is easier to manage, and can be profitable if the airlines relize that they aren't unlimited resources, and decentralize the hubs on a limited basis.

Anyways Southwest doesn't drink anyone's koolaid, they run all their own in house designed systems (I am not sure they are even on Sabre anymore), including web apps. It's an intresting concept, but it probably causes their IT managers to pull their hair out.

Re:Southwest refuses to drink the Kool-aid

Actually, the only thing that makes these sort of problems easier for Southwest is the consolidated fleet types. With nothing but 737's, you don't add complexity to the scheduler for things like pilot and f/a qualifications.

What happened to Comair here could happen to just about any airline. There is no comprehensive suite of software that handles crew scheduling, aircraft scheduling, reservations, and the myriad of other functions that are needed to run an airline.

Reservations, for other than tiny airlines, are still managed by large TPF mainframes. TPF is a very "bare bones" operating system that runs on IBM mainframes, and was written specifically to deal with high volume / high transaction rate systems. Personally, I've seen 5 attempts at 3 different airlines to replace it with something modern. ( like Unix with an RDBMS ). Each attempt failed miserably, and the airline went back to TPF. Note that TPF is not MVS, OS/390, or any other more mainstream Mainframe OS. It's purpose built.

Unfortunately, this means that all of the other applications have to interface with TPF via screen scraping. To further compound the problem, no "suites" exist to handle the following functions, so most airlines have to "sew together" best of breed solutions for these basic functions:

• Crew Scheduling - F/A's and pilots bid on slots to fly, this system takes those bids and turns it into a schedule.
• Aircraft Scheduling - Tracks which tail numbers are flying which flights for the dispatchers
• Optimization - Different optimizers to do things like:
  • Fuel Tankering - Use the jets as "tankers" so that you buy fuel where it's cheapest for flights later in the day
  • Crew Optimization - "Traveling Salesman" type solver to incur lowest labor cost, get crews back to home base, etc
  • Schedule Optimization - Use the aircraft in the most cost efficient way to cover all of your scheduled flights.
  • Maintenence Optimization - Pull aircraft in for Scheduled Maintenance at the optimum time.
  • Reacommodation - When things go wrong ( weather, mechanicals, whatever, pull in all of the above variables to crank out a new schedule, crewing, mx schedule, etc )
• Booking Engines, for the internet and reservations agents
• Point of Sale and Boarding functions for agents, skycaps, and kiosks
• Interline functions where other airlines sell your tickets, and transfers for bagggage, etc

Anyhow, this list isn't comprehensive, but shows enough of the disparate pieces that you can imagine why these "glitches" happen. Very few of the items from the list above come from the same vendor, or even run on the same platforms.

Possible system OS

Judging by www.comair.com and their job ops, it's probably HP-UX or Windows. More than likely the Unix flavor rather than Windows. Why down for a couple of days, probably a database restore. Never happens in TPF. Those mainframe systems crash and are back up with very little database degredation. By the way, in the job ops, if you want to be a crew scheduler, only need HS diploma!

Must Account for Overbooking

The system should only be able to hold as many reservations as it has flights/seats.

Useless commentary. Airlines overbook to fill planes and the system has to accomodate this.

Huh?

What kind of system just totally crashes?

Is that a trick question?

Probably TPF

More than likely it is TPF as Delta is a TPF shop.

TPF (http://www-306.ibm.com/software/htp/tpf/index.htm l) has been around since the '60's and is used by all the major airlines, most of the large hotels and most bizarrely NYC 911.

Here is a clue

Does anyone know what platform their system was based on?

This site [alancoxonachip.com] has a clue: check the link about Alan Cox's Windows 2000 snapshot capabilities. ;-)

Simple Solution

Take Amtrak!

Amtrak receives around $500 million for a total budget, while the airtravel receives around $15 billion in subsidies. Take the train and save everyone money!

_____________

Re:Simple Solution

Sure, that's eminently practical. I can take 48 hours to get from Detroit to LA, or I can take six (including travel time and check-in time at both airports).

p

Delta fuct me and didn't even kiss me!

I got into Boston on the evening of the 24th for the final leg of my HNL-YFC flight. The small gate area for Comair passengers was overflowing with-not-so-happy looking folks. Checking with a few of them I discovered many had been waiting since early afternoon for their flights, with nothing more from the Delta folks but glib, non-informative announcements now and then. The aircraft were on the ground, but there were no crews available to fly them. I waited patiently while my flight got delayed and delayed again. Finally, after many passengers took the only available flights remaining to alternate destinations, did Delta/Comair finally admit our flight was cancelled. They gave us hotel/meal vouchers (well, I got a hotel voucher anyway) and we went our way disappointed but expecting to get to our destinations a day late.

The next morning when we arrived back at Logan, our flight had already been cancelled. The lineup stretched from one end of Terminal C to the doors leading to Terminal B, and then some. While we waited, an airport rep was walking the lines asking where people were going. When our Comair destinations came up, he said "Go home. There'll be no flights out until maybe Monday or Tuesday." I thought people were going to cry right there. Our little band decided to try renting a car and driving. No luck, with no cars available at Logan that day. We tried buses, but no buses were running to our destinations that day. I seized upon the idea of using my Air Canada Aeroplan miles to get a free ticket to my destination (plus booking and taxes, $60).

When I was waiting in the Air Canada line, I saw one of the people I was with earlier. She told me the Delta rep told her to go to other airlines and ask if they would give carriage based on the Delta tickets she had. Basically, Delta was telling people they were on their own. One guy told me he watched a Delta agent tell a lady to fuck off. Anyway, I got to the counter and asked the Air Canada agent if they were doing anything for Delta passengers. She told me unless Delta signed the ticket over to us they were not doing anything special for us. I didnt know what that meant, but I knew Delta was doing fuck all for us, so I went ahead and used my Aeroplan mileage ticket.

The Delta fuck-up was basically all the news on Christmas and Boxing Days. Even the Canadian Immigration guys who never talk or joke around were feeling sorry for us. I dont know what I can get from Delta for the HUGE PITA they caused me, but I dont think Ill ever fly them again.

response from an AA employee

I sent a summary of these Slashdot comments to my cousin who works at American Airlines hq in Dallas. Here's his response!

---

"ugh... I worked 9pm-1am yesterday (xmas day). I spent the first two
hours of my shift calling people to tell them their flight was
cancelled and reschedule them. Most of them were taking flights out to
Miami and the Caribbean to spend New Years Eve partying on the beach.
Honestly, I had little pity telling them they were going to miss out on
one day of tanning especially since they seem to 'blame' the weather on
us.

"One hour into my shift our reference system went down. No IT people
were willing to come in and fix it. I had the system up for booking
flights and making reservations, but I could not look up any of our
rules and regulations. Ah well, enjoy your xmas off IT guys!! Enjoy
the weather in Cabo San Lucas!! Cheers!!

"Fortunately, we have a backup of all our html files saved as text
files. However each text file can only hold serval hundred text
characters. So, when I want to look up our baggage policies the normal
html file is called BAG INFO. In the backup system BAG INFO is
separated into 10 or 20 text files and I have to 'page' through them by
typing BAG INFO P2, BAG INFO P3, BAG INFO P4. The text files are not
indexed and are not searchable. It took me 10 minutes to find and
advise someone how big a bag they can take to Puerto Rico.

"After I started taking incoming calls again, there were people calling
in on Christmas day to book their trips for Spring Break. There were
over 100 calls on hold to talk to us, and there were people sitting on
hold for half an hour to ask me how much it would cost to book a trip
to Fort Lauderdale in March. Couldn't that wait until the day after
Christmas?

"Yes, the airline industry does not prepare for emergencies as well as
it could for the holidays when people want to travel in record numbers.
However, I think the general public could try to have their own backup
plans in place as well and realize that the travel industry in general
does not have the equipment or the staff to handle everyone in the
country wanting to travel all at once in one week. Do people stock
their refrigerators year round with enough food to feed everyone in
their families at one meal like they do at Christmas?

"Even though we try to accommodate everyone as best as we can on the
holidays, we want to to have a holiday just as bad as the rest of
everyone else. Working in the travel industry should not indenture us
to be your slaves over holidays. The public needs to have a little bit
of compassion and realize how much we give up in our own personal lives
just to help you get where you are going. Frankly, the way most people
treat me on the phones I don't think they deserve our help and
compassion. And don't call on Christmas day to book flights in March.
That phone call is making someone work on a day they shouldn't have to.

"anyways.... heh..... guess i had a bad night at work last night, huh

"MERRY XMAS!"

Proof that you guys mean NOTHING to Joe Sixpack

A freak weather event did more damage to a computerized reservation system in one night, than all of the hackers, viruses, trojans, spyware and idiot lusers combined over all of 2004.

Unless you take the overinflated guesstimates of the likes of mi2g at face value, anyway.

Toronto faced a blizard last week. Some two hundred flights cancelled because of bad weather. Air Canada, West Jet, Jetsgo, etc didn't go down even if their planes did. That too, caused more damage to YYZ's fiscal health than all of its computer security woes combined through 2004.

And then I read the letter posted here about the IT guys sunning themselves during all of this.

Merry xmas. I hope you can justify your jobs in 2005.

Surely you know the ditty ...

Time to spare?
Go by Air.

Some clarification

Well... to try and provide a little clarification here, as I work for Comair. Here's the skinny:

Crew and aircraft scheduling is done through a software package called SBS Track. This very same software package is used by many other airlines, including the two I worked for before coming to Comair. I don't know if their systems have the same hard-coded limit that ours does or not. This software package has _nothing_ to do with reservations, or anything concerning passengers whatsoever. It is simply the software we use to schedule our aircraft and crews to fly the list of flights that Delta wants us to fly.

Crew scheduling is done by creating "pairings". A pairing is a sequence of flights that comprise a crewmember's trip. Anytime a change is made, a new pairing is generated, with the new sequence of flights. The system has a hard-coded limit of 32k pairings ("transactions" is the what the IT folks call it) in a calendar month. As of 10:00 pm on 12/24, that limit was reached. Crew Scheduling was unable to create any new pairings, unable to track who would be flying what airplane to where, and basically unable to keep the airline flying at that point.

It was not any kind of a hardware failure, there are backups for that. It is simply a software limitation, that when it was coded many years ago, nobody realistically thought it would ever be reached. Why they hardcoded a limit into it in the first place is beyond my knowledge. :)

A major part of the problem is Comair's concentration in Cincinnati. CVG is our only crew base, and it is the largest single crew base of any airline in the world. Over 1800 pilots and 1100 flight attendants in one base. Not even any of the majors have a single base that large. Several of our software packages are woefully inadequate, and replacements have been sought for some time.

As for getting things up and running on paper, this is a monumental task. Scheduling for 160+ aircraft and 2900+ crewmembers, and compliance with all FAA regulations, maintenance requirements, crew rest requirements, and contractual requirements is incredibly complex. In addition, we have crews and aircraft stranded across the country due to the weather that moved through that caused this whole mess in the first place. Add to that the very limited number of people who actually have the knowledge of all the requirements for scheduling, and coming up with a full schedule for the next day would be nearly impossible.

Jan. 1 starts a new month, and the system will return to full functionality then. Until that date, however, our operations will be very limited.

Oh jesus christ...

Some of you have no clue.

The BS&T quotient on your average travel application is on the relatively nuts scale. Expedia, Travelocity, hotwire, priceline, whatever -- I'd ask that some of you with simple solutions go and speak to the lead travel-server dev for the product.

You'll probably have to change pants after the conversation. Travel is stable, reliable, and generally rock-solid. The algo's for selecting airline flight prices or hotel room block-reservations are known and well-tested. The methods and protocols of communication are well-documented and generally straightforward.

Until recently, it was all on hardware (And i'm speaking generally about the large travel providers -- Worldspan and Sabre come to mind) that was considered arcane. Ancient versions of Netware on an X.25 pad; screen-scrapers on top of it. Have Fun trying to modernize!

This does not suprise me in the slightest. We are stressing our ancient systems more than ever these days, and it should not be a suprise when the occasional ancient application (ctime, folks) gets floor'd and dies a bloody death.

It'll be patched in a month.

Maybe example of too much Horizontal vs Vertical

Vendor A, B, C, ...; package Z, Y, X, ...;
integrator 1, 2, 3 ...; contractor ....

Maybe I'm too old, but it sure was nice when
at least the applications were written in house,
yea we would bitch when the writer of the code
was long gone, but still, we could fix it.

Oh well, I just wish I chould get use to saying
"its the vendors fault" when ever something goes
wrong.

Conair made the descision not to replace/upgrade
before January. End of Year, make the profits look better ? The roll of the dice ?

-pete

Re:The system runs Linux

No, it means they didn't make a big enough swap partition.

Re:The system runs Linux

Yeah, but the real cause for the crash was an Access backend. So there! :)

Re:Slashdot this

Don't smirk; it'll be the next topic on Ask Slashdot.

Re:Outsourcing, of course!

Yep, They will do anything to "cut costs"

Re:Huge earthquake

Okay, nobody's going to read this, because it was yesterday's story and it's been modded into oblivion.

But can somebody please explain to me how this is off-topic? Somebody posted something that wasn't, admittedly, perfectly on topic (but worth a `Flamebait' more than `Offtopic') and I replied to that exact post.

I could cope with being modded Flamebait. Having a read, it probably does qualify. I'd even be happy with a Troll. But I made a perfectly relevant, and thus ontopic, reply to a post.

I could go on, but there's no real point. Metamods, a bit of justice please?