Slashdot Mirror
What is Mainframe Culture?
An anonymous reader asks: "A couple years ago Joel Spolsky wrote an interesting critique of Eric S. Raymond's The Art of Unix Programming wherein Joel provides an interesting (as usual) discussion on the cultural differences between Windows and Unix programmers. As a *nix nerd in my fifth year managing mainframe developers, I need some insight into mainframe programmers. What are the differences between Windows, Unix, and mainframe programmers? What do we all need to know to get along in each other's worlds?"
Comment removed based on user account deletion
"What do we all need to know to get along in each other's worlds?""
You could try exchanging porno links to one another, that seems to be the way nerds bond. Just a thought.
..Punchcards, ENIAC tattoos and nipple piercings that look and spin like tape reels.
Starsucks
Herding Cats. Some are big, some are small, some aren't cats at all.
Sorry about the writing. Robot fingers, you know? Cliff Steele in DOOM PATROL #23
"Giant Fucking Flamewar on /.: Story @ 11"
https://www.accountkiller.com/removal-requested
The thing that's really preserved the mainframe over the past couple of years has not been performance; it hasn't been throughput, because those things turn out to be terrible. It's been the set of operational practices that have been codified around it. Mainframe culture and rigorous "change control," contrasts with the PC server culture of "whiz kids" who never learned the basic operational rules necessary to avoid costly mistakes.
This "anonymous poster" has been managing mainframers for five years, is a Unix nerd, and doesn't already know how the three cultures are different? Or are they just a Windows troll, stoking the flames of the OS holy wars?
--
make install -not war
Unix and mainframe programmers are more likely to know multiple systems, out of necessity, and consequently have a more general understanding of the commonalities of all computer systems. Windows-only programmers are more likely to know The Microsoft Way, and only The Microsoft Way. They're less likely to know standard terms, and will only know Microsoft's replacement terms. At least in my experience (and these are tendencies with plenty of exceptions).
The difference is one programs Windows, one Unix, and one mainframes. As a fifth-year geek, you should take the rantings of Joel, ESR, and any other pointless windbag and send them to the bit bucket.
The main difference is one of resources. The mainframe folk utilize a shared resource: the Mainframe System. You may have parallel hardware, but from their point of view it's a single system. There's no ability to install a quick machine to use as a test server. Sure you can have test CICS regions or test OS partitions, but if you bring the hardware down you bring the datacenter to a screetching panic. Worse, you can piss off the operators and have 0.00001%CPU for the rest of your tenure. This keeps a certian unspoken level of panic about. Don't worry if you notice it bubble up when one of your coders fucks up. The panic symptoms will pass as it goes back down to it's normal level. It won't go away though. ;-)
Which brings me to scheduling. Remember that production=batch and batch knows no sleep. When code goes to production, it's just as bad for the stress level as a major version release of other software or a website launch. Unfortunately for the MF coder it happens a lot more often. Having to talk to your operators when you can't even see straight (from sleep or other things) takes something that is unique to this kind of coder. On-call programming takes talent and some craziness. If you can find where that is for each of them, you will realate to them well.
One last thing: make your coders work in operations for at least a week. They will have a better understanding of the hardware end and productivity will go up. There's a reason that the best coders are in the computer room a lot.
US Democracy:The best person for the job (among These pre-selected choices...)
I think it's the beards. Windows programmers are usually cleanly shaved, unix programmers are usually bearded, and mainframe programmers usually have gray beards. They probably have a distinct smell, but I'm not going there.
:-]
For Unix devs:
1. Learn to CamlCase your API, variable names, etc.
2. Turn all '-' or '--' into '/' in command line arguments.
3. Use 'dir' instead of 'ls -l'
For Windows devs:
1. Learn to lowercase all your API, variable names, etc.
2. Turn all '/' into '-' or '--' in command line arguments.
3. Use 'ls -l' instead of 'dir'
I once had a signature.
Windows programmers don't know how to program without a GUI.
Linux programmers don't know how to program with a GUI.
Mainframe programmers wonder what a GUI is.
end humor transmission.
I am scientifically inaccurate.
The reasons mainframes are interesting, to the extent that they are, is that they can handle very large databases with very high reliability, which is not the same as being fast (though some of IBM's newer mainframe products are also quite fast.) That means there's a heavy emphasis on building and following processes for deployment and operations so that things won't break, ever, at all, even when the backup system's down for maintenance, and on building processes to feed data in and out of this rather hostile box so every bit gets bashed like it's supposed to. The programming environments have gotten better, but you're looking at a level of flexibility like Debian's Oldest-and-most-stable releases, not like Debian sid.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
The length of the beard?
Mainframers know that you cannot reboot a machine willy nilly, since someone may be running a simulation that takes 6 months to complete, he may be in month 5.5 now and on first name basis with the guy that normally signs your pay cheque...
Oh well, what the hell...
Unix programmers like their code like the old legos. Each piece might be a different size or shape, but the bottom of one snaps onto the top of another and the ordering and number of pieces used is left as an excercise for the reader. With experience, anything can be built with the pieces, and yet each piece is simple and easy to understand.
Windows is like the new lego sets. You get specialized premolded parts suitable for one specific task, plus two or three additional add-on pieces that give the illusion of being fully configurable for any task. You can build anything you want with the new legos, as long as you only want to build what is on the cover of the package.
Yeah, that's it in a nutshell.
As a *nix programmer forced into the mainframe world, I'd have to say that m/f programmers do not look at computers as a hobby or thing of interest. To them, programming and computers are just what they do to get paid. To the m/fers, a computer is just a tool that they have to use to do their job. They take no joy or pleasure in programming, it's just what they do.
On the other side of the coin, I think that *nix and Windows programmers tend to enjoy what they do. To them, programming is not just their job, it's enjoyable.
Honestly, I don't blame them. M/F sucks. As soon as you get your first compile error because your command isn't in the right column, or have JCL spit out a bunch of random nonsense because you didn't allocate the correct blocksize for your file you'll hate your job too.
Dear diary: Today I stuffed some dolls full of dead rats I put in the blender.
The word you're looking for is "user", not "threaded". From my experience, Windows coders are much more knowledgeable about threads than Unix programmers. Back when I was just learning some POSIX programming (I've been doing Windows programming forever) I'd ask even halfway experienced Unix programmers how to create a second thread in my program's process, and the usual response was "why on earth would you ever need to do that?"
You have tried to support your argument with faulty reasoning! Go directly to jail; do not pass Go, do not collect $200!
From the article:
*Unix Programmers* don't like GUIs much, except as lipstick painted cleanly on top of textual programs, and they don't like binary file formats. This is because a textual interface is easier to program against than, say, a GUI interface, which is almost impossible to program against unless some other provisions are made, like a built-in scripting language.
I would disagree with this assesment, instead I would say people who prefer textual interfaces do so beacuse they often offer a much denser display of information. You can get a lot of information packed into text that may be quite spread out in a GUI.
Also I would say that people eventually come to favor programs with scripting interfaces.
It seems to me that as users grow more sophisticated eventually all users become programmers in at least a specific domain, or at least desire to. All users grow used to a tool, and after a while they start wanting more dense an informative displays.
Just look at PhotoShop, probably one of the longest running commercial applcations (i'm sure there are others that elude me but it's just a really good example). Does that even follow any kind of UI guideline? No it does not; there are so many users that have used it for so long, that they demand a richer and more complex interface. Over time they demanded plugins and then of course scriptability (through actions).
Yes Windows was a way to bring many people into computers that could not have come through UNIX. But in the long run users grow into wanting more flexible uses of the computer and they start leaning towards the "UNIX Way" and looking for apps that are pluggable and scriptable.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
Just look at the tools in the trunk of their cars. The Linux and Windoze guys will have a few screwdrivers rolling around there. The mainframe guys have blowtorches.
Don't blame Durga. I voted for Centauri.
That is not the best assumption, as the Windows app is likely to be running alongside Bonzi Buddie and at least 7,000 pieces of malware and virii.
Don't blame Durga. I voted for Centauri.
That IS a good question. In Unix, creating a new process and using IPC is so simple, you almost don't need threads. In fact, before POSIX threads, Linux threads WERE processes. The advantage you got over threads was cleaner separation of memory and variables -- always worth a lot when programming in three-star C. The disadvantage, of course, was that same separation meant that everything you wanted to share had to go through IPC.
I was working with IBM MVS (batch oriented) and VM (interactive) for quite a while. At that time the main choice was between COBOL and Assembly Language (BAL/370). COBOL provided some basic routines, but do to something interesting (like asynch I/O, your own memory management, etc) you had to use BAL.
The following example might be interesting, not sure if helpful. On batch system you have many jobs executing concurrently. MVS (at that time) didn't have anything like preemptive multitasking. COBOL didn't have asynch I/O either, so when it issues I/O it just goes into a wait state, so another task is scheduled. So the bottom line was that your program won't be very efficient (e.g., won't be overlapping I/O and CPU activites), but that would create a nice (from MVS perspective) mix of jobs. Some are doing I/O, some are doing CPU, so MVS can accomodate many concurrent tasks.
Well, at that time I was budding assembly language programmer and even took a course at university where we had to write our own operating system, entirely in BAL/370, including the Initial Program Loader (boot, if you wish). I was working at the same time, and there was a problem at my job. They (John Hancock Insurance) had hundreds and hundreds of COBOL programs, and nothing like cross-referencing dictionary, like which program modifies some common record fields. So when something unexpected happened, they had to search through the source code, to find all the instances of such references and that was taking something like 5-6 hours. I've learned asynch I/O at school and how to overlap I/O and CPU activites, and I've ended up writing fairly efficient program. Program was reading large chunks of disk data into several buffers. As soon as the first buffer was full, that event was detected, and the program starts parsing that buffer for some keywords --- while continuing reading the tracks into other buffers. (it was a circular list of buffers). After some trials I got the execution time down to less than 20 minutes. Everyone in my area was happy.
Everyone except mainframe operators. I've been told they HATED my program to its guts. The problem was that the program didn't behave nice as far as 'good mix' is concerned. It grabbed the resources and hold them for a long time because it went to the wait state only occasionally. But that was a great help for production problems, so they had to let it run.
That was many years ago. I don't know if MVS got changed so to introduce preemptive multitasking. At that time it was a strictly batch-oriented system. All I/O was executed in a separate subsystems (channels). To run something interactive (like CICS) wasn't trivial at all. The best strategy was to dedicate entire mainframe to such task. Mixing CICS and batch jobs int the same machine was suboptimal solution. Of course, MVS scheduler got improved since, to provide better balancing between batch and interactive tasks, and yet, as I understand, MVS fundamentally remains batch operating system.
Mainframe guys don't reboot their system. Unix guys reboot the system occasionally. Windows guys reboot their machine several times a week.
... I have plenty of karma to burn, and this looks to have been posted to start a huge flame war. Why fight fate?
1. Windows is teh bestest, like EVER!
2. Unix is ok, you get good at typing...
3. Linux stole from SCO!
I will now invite retorts. (ducks)
HA! I just wasted some of your bandwidth with a frivolous sig!
And...
The Windows Dev need a P4 with a gig of ram.
The Unix Programers can do it on a P4, but it'll work just fine on a Mot 68K or a 486.
The Mainframe Programmers think a Ti-92 has too much horsepower.
You could try exchanging porno links to one another, that seems to be the way nerds bond. Just a thought.
You are sooooo right, and if you handn't posted as an AC, I would have sent you this sweet link, called goatse.cx, to cement our friendship.
HA! I just wasted some of your bandwidth with a frivolous sig!
Windows programmers work from the assumption that their job is to protect users from the machine.
Mainframe programmers work from the assumption that their job is to protect the machine from users.
Unix programmers work from the assumption that they're the users and the only protection they or anyone else needs is knowing enough about what they're doing. They also work from the assumption that "enough" means "as much as I know", no matter how much or little they know.
2/3 of Macintosh programmers think the same as Windows programmers. The other guy doesn't think about it.
I'm still an Apple II programmer. I still think it's a good idea, and necessary, for everyone to be able to program down to bare metal, because it's only for showing off what you can do since everyone is going to do their own programming anyway. At this point I believe that the only way I'll ever see any Apple II op code coming from anybody else would be if that's what they decode from the SETI signals.
"I may be synthetic, but I'm not stupid." -- Bishop 341-B
Have you ever written a program in an environment where if it malfunctions once during operations, the incident will be investigated by a review board? The board will want to know why it failed, and what is being done to prevent it from happening again. Then there is configuration control, requirements traceability, test plans, software build procedures, security audits, etc.
Mea navis aericumbens anguillis abundat
1. Windows programmer: There are two sub-phyla of Windows programmer:
A) Fanatic Windows programmer: Refuses to use any software not made by Microsoft or an approved Microsoft partner; openly mocks Linux, unix, Firefox, and you when you suggest any of the three; programs exactly the way Microsoft tells him to in MSDN articles, and is deeply distrustful of any different approaches; loves IE and is laden with spyware and viruses, but refuses to admit it, saying things like "it's the hardware; I need a new machine".
B) Normal Windows programmer: Uses Windows because it's what everyone else has (and he wants to sell them things); uses Firefox and generally avoids IE; understands that Windows is limited and imperfect, but finds it useful for some subset of tasks; is interested in Linux but vaguely irritated by Linux fanatics calling him a sell-out. Secretly wants to eat spicy Schezuan with the Linux geeks, but not that fanatic with the blue hair (she's too freaky);
2. Linux (2 sub-phyla):
A) Fanatic Linux user: despises Windows users, seeing them as the zombie hordes following Bill Gates, his Satan; throws things at Windows users when they're within range, shouting "Shoo! Shoo! Get back on your short bus and go home!"; compiles everything from scratch to install, because otherwise he'll feel unworthy; generally only uses "Free" software, eschewing anything even remotely non-free, which seriously limits him. Secretly feels betrayed by the moderate Linux users, wants to eat Schezuan with them but knows that Windows guy will be there, so goes for pizza instead.
B) Normal Linux user: Uses Linux because he doesn't have to worry about spyware and viruses (much) and can simply use and enjoy his machine without having to put up with a lot of annoyances; is intrigued by Windows but dislikes the Windows fanatics, who make fun of him (he suspects they live in a town with lead water pipes, and forgives them in pity); he generally doesn't care what other people use as long as his Slackware instance is running well; he occasionally uses Knoppix to rescue one of his Windows-using coworkers when their registry gets corrupted; Secretly enjoys the look they give him after he recovers all their data, it makes him feel Wizardly. LOVES Schezuan food.
3. Mainframe users: Aren't sure what all this "Linux" and "Windows" nonsense is about, and suspect it's a fad the kids are following; Are very fond of their new VT-100 terminal (2400 baud! Kick ass!); Are starting to suspect they might be in for some trouble -- they've had to page all their data off disk to tape a THIRD time this month, how can their disks keep getting full? They're 40MB!!! SOMETHING funny's going on... Are secretly nervous about the boss and that young intern kid and the new box they've been setting up in the corner; those two keep giving us significant looks, what IS that, some kind of new networking thing? Bill over in tech support said it had "blades" in it...; and they still laugh about how "Emacs Makes A Computer Slow". Ha ha ha! Snort!
Farewell! It's been a fine buncha years!
When a mainframe becomes loaded with spyware, you do not throw it in the dumpster!
Unix is process-centric. Windows is thread-centric. This is also an artifact of GUI programming. For example the GUI should never stall by processing a request. Instead it should fork off a thread
:-)
This has nothing to do with GUI programming and everything to do with the cost of creating a process on NT. People began abusing threads because it was so painful to use processes.
Most unix apps don't use threading. This is not for lack of threading or knowledge of how to use threads. It's simply that processes are as cheap as threads and offer more protection.
Nearly all Windows development involves a GUI. This is usually done with an event-driven API. On the other hand, many Unix geeks probably never program in the event-driven paradigm.
Long before Windows existed, X-Windows had a callback, event driven mechanism for GUI programming. This resulted in considerably better performance than the message mechanism used in Win16 (which was carried over to Win32).
The reason for using messages in Win16 was simple--there was no real multitasking. Context switches didn't exist so there was no difference in having a process handle events it cared about verses every possible event (with a standard default handler).
The problem with most Windows developers is that they don't understand the history of Windows. They pick up things like "event-driven paradigm" as if it was some great innovation that makes their lives easier. That my friend, is the power of marketing
I've done a lot of mainframe development and a lot of Unix/Linux development; scarcely any Windows.
The main difference I see between mainframe development and *ix development culture is respect. With the mainframe you have to book time days in advance and work in the wee hours to make any changes. And you make damned sure that, when you're done, things work as they should.
With *ix development, things are laissez-faire. You send out a message a few hours/days/minutes in advance of some monumental change. Then you blame the users when they can't sign on to their system in the morning. Quote some recently-adopted standards if they argue.
Of course, I'm speaking of the early days of *ix. These systems are more and more critical, and the admins are trying to learn respect. But they're playing catch-up. There's nothing like the fear of taking down a $500/minute system to make you careful.
Windows development follows a similar pattern. The whole culture is so "personal computer" based that the concept of a year's continuous uptime is foreign.
[ ] Unix
[ ] Mainframe
[ ] Windows
beard #2
[ ] Unix
[ ] Mainframe
[ ] Windows
beard #3
[ ] Unix
[ ] Mainframe
[ ] Windows
But I bet you'll notice a core psychology that's pretty familiar to most geeks...
I've also had the opportunity to train mainframers in shops where MVS platforms were displaced by *nix based platforms. So, here is a subject that, no doubt, I can speak about:
The major factors/differences:
First, most of the mainframer programmer contingent has been moved offshore or is being done by NIV programmers. Really not much of a career path here, but OTOH, a great deal of critical systems (charge card processing, airline reservations, utility company systems) are still coded in MVS COBOL/DB2 (or IMS, a hierarchical mainframe database platform for IBM MVS). To convert these systems means you need to be able to understand these systems, and please don't give me a business analyst -- the days of their expertise are long gone, and the metamorphisis of systems over time means business knowledge is embedded in the code.
Mainframers don't get GREP. I've tried so many ways to impart this wonderful tool, but all I get back is puzzled stares and bewilderment, for anything more complex than what could be accomplished with a non-regex, or simple wildcard search.
Globals. This is something that put me aback 6-7 years ago, when I made the leap into Unix programming, and traded C/REXX/CLIST for C/Perl/etc... COBOL is structured into divisions and all your data declarations are laid out and globally accessible. Though many COBOL systems are quite complex, with a "program" actually being a driver for a whole hierarchy of 20-40 sub-programs, and the necessity to restart at a given point in processing can make things quite complex.
Approvals, checkoffs, signoffs, and procedures. They're largely absent in the Unix (and most webdev work) world, but mainframers have grown accustomed to reams of authorization and approvals for even simple changes. Lead times of a week or more, along with VP signoff, QA signoff, user group signoff, fellow developer signoff, etc.... Even getting a downstream system to agree to test changes may take a formal request process and budgetary allocation of thousands of dollars. This is probably the biggest divide, and future schisms will be prevalent, as data center leadership trys to impose this kind of checks and balances on developers not accustomed to these obstacles. IBMs trouble and difficulty in the web server world offer a prime example -- business being told that it'll take 3-4 months to get a server online, and folks who know better just can't understand that.
Lack of user tools. A big part of what I did as a mainframer was building tools, using BTS and File-Aid to allow developers and testers to create their own test bed and automate the test process. On Unix side, the tools come with the OS, and awk, Perl, and all the other CLI goodies make automating testing a snap.
File in/File out vs. piping. Mainframers have a tendency to see everything as file-in/file-out. In a way so do *nix coders, but a seasoned *nix programmers sees the tools all being able to feed eachother. Rather than step1 filein fileout, step 2 sort filein, out fileout, step 3 filein, reportout, etc...
On the age thing, most of the really skilled mainframers now, like myself, do Unix or migrated to Java. Others are awaiting retirement, or head over to six sigma teams, business analyst roles, or seek refuge in management, escaping the axe that clears the way for the offshore coder.
Paper over softcopy. Got to have that printed listing, and the sticky notes (and before that, paper clips). I still remember a senior manager telling me when I first broke in how his appraisal of a programmer was how many fingers he needed to act as placeholders when he perused a program listing.
AZspot
First, I am not your typical Mainframe admin / programmer, as I am 27 and a relitave expert on mainframe constructs like JES, JCL, SMF, SMS, and RACF. From my 5 years of experience working in the mainframe operations group I've noticed the following differences and similarities from Linux (I'm a home user) and Windows (my work laptop):
- The mainframe is highly structured in it's change management procedures. This is an artifact of how long mainframes have been around. The procedures support the mainframe's goal of 24x7x365 uptime.
- Due to the high level of structure, there are usually at least 3 groups (often times many more depending on the size of the orginization) that are responsible for the mainframe: System programmers, Operators, and Application programmers. Each fills a very specific role in the operation of a mainframe system.
System programmers are typically responsible for the health of the operating system, and installing new system wide applications from vendors. The nearest match for system programmers is a Unix admin or windows admin.
Operators provide the 24x7x365 support aspect, making sure that the hardware is healthy, jobs are running, and important business applications remain available or come up on schedule. Operators may also be responsible for the scheduling package, and security. Again in the Unix world, this is equivalent to the system administrator. The operator position originated because mainframes at one time required people to run around and physically mount tapes and disk drives, and to spite automation that takes care of these tasks, the position remains.
The final group, application programmers, are what are most frequently though of when talking about a mainframe. They tend to work in languages like COBOL, CICS, DB2 stored procedures, and on occasion Asembly. Their role is to produce the online and batch applications that process the transactions that make the company money. App deveopers on the MF tend to be very carefull about testing code to ensure the proper result because first it could hurt the bottom line, but mroe importantly the operations group won't let it run in production with out assurances that it will run smoothly.
- Mainframes have been built from the begining for reliability, availability. scaleability, and performance. IBM accomplished this by virtualizing everything. This virtualization allowed IBM to have duplicate pieces of hardware internally double checking each other. For example, every instruction is run thru two physical CPU's at the same time, and if the result is different, the diagnostic code kicks in, disable the CPU that's incorrect, and calls IBM to replace it. This method of RASP is very different from what you see in the windows and unix world where multiple machines are load balanced with geographic redundancy, and if 1 box fails, the others pick it up.
- Operationally, in a windows or Unix/Linux world if you need to run sumething you just run it. In the mainframe context you submit it in a job to JES. JES (Job Execution Stream) is a resource manager that manages all the mainframe resources for executing jobs and tasks. The biggest difference is that on a mainframe yor job or task may not start running immediately if resources are not available, unlike Unix or Windows where it will start taking time away from already running tasks.
- Development on the mainframe is usually given very low priority for resources, in order to ensure that the production onlines and batch get everything that they need. Where Linux and Unix have 40 levels of priority (20 to -20) The mainframe has virtually unlimited priorities, because the system programmer jugles CPU, DASD (disk to the uninitiated), tape, and resource wait information to determine the real time priority of a particular task using relitavely sophisticated algorithms to do so. Because of this the system can be tuned very specifically to give the most resources to the tasks which earn the company the most money.
Like this?
The truth about Scientology, Xenu, and you: Operation Clambake
> Linux programmers don't know how to program with a GUI.
> Mainframe programmers wonder what a GUI is.
Corollary for end users - and yes, my Dad's first email message to me was indeed sent in all caps:
MAINFRAME USERS THINK THAT USING ALL CAPS WHEN SENDING MEMOS IS PERFECTLY NORMAL
Linux users think that using all caps in email is YELLING.
windows users dont no how 2 use nething but there im proggy
1) While most programs today should probably not be written in C, I think it's still an important language to learn and understand as a beginner programmer. Most applications today use C at some level. If you understand it, you get a chance to understand how the application/framework/library you are using works which make you able to use it better. See Joel Spolski's "Back to Basics" for more on this.
3) More on this in Robert L. Read's How to be a Programmer.
No GNU has been Hurd during the making of this comment.
Oooh.. touch a nerve did we?
You missed the point (and the humor) of the OP.
Firstly, was that a question? Secondly, nothing. Yes, you can do it all in Windows. The point you originally missed is that (s)he was referring to the whiz-bangetry of
Bottom line is, older UNIX folks are much more likely to have written the mass majority of their own code where today we see CASE tool technicians masquerading as software engineers. I see this at work all the time with the "new generation" of IS/IT types rolling through the door who couldn't code a b-tree save to save their lives and rely on prebuilt everythings to give the illusion that they do something "difficult".
Got news for ya folks, my Subaru tech has more skill than most of these chumps.
Isn't the whole point of an operating system to allow programmers to make that assumption?
No, the whole point of an operating system is to provide a stable programming target and perform resource management.
I didn't get into the industry until 10 years ago, and I was amazed at this difference between the windows kids and the mainframe guys. I was a Windows/Oracle developer, but luckily I learned good practices from old MVS/greenscreen guys who taught me things that hold true no matter what kind of computer platform you're working with. I'm blown away to see some of the stupid things that new programmers/admins do. Blown away
I feel the same way whenever I look at the SMTP spec, the MIME spec, the SMTP email format spec, pretty much any on-the-wire specs actually...
At the very least people could prefix strings they're transmitting with the # of bytes in them, so that memory access is efficient.
Look at HTML - all ASCII. ASN.1 was invented so that you didn't have to use all ASCII for this kind of data (look at the SNMP spec if you want more details). But does anyone use it for the on-the-wire format? No.
Unixheads seem to claim that it's perfectly admirable to hack around the ASCII format for everything because it makes it easier to debug, whereas all I see is wasted entropy and bandwidth.
Anyway...
Coming soon - pyrogyra
I am a *nix padawan, but, crocky technology asside, I'm frequently impressed by my Mainframe elders, their ability to deploy code to Production environments that works *the first time* nearly every time, and their ability to communictate technical changes necessary to fix broken code in the middle of the night in the 0.1% of cases where they failed to get it working first time.
Key values that I have picked up from my masters, and which should be inherrited by both *nix and PC/Mac enclaves are focused around Engineering principles. Mainframe guru's program like a civil engineer builds a bridge. No shortcuts are taken unless it can be proven that it is safe to do so. Testing is carried out in stages and test results must be submitted with the change request before a program migrates to Production. If a program must "abend" (Abnormal End) then it should do so noisily and with as much information as possible. If it finishes cleanly, little information is needed other than this fact.
These closely follow the advice Raymond has encoded in his book, but there is probably much more that your Mainframe gurus know that you should cherrish and extend to your newer team members.
Forget about the religious wars, the technology changes and the "focus" of your programmers on users or other programmers. Get the real truth from your Mainframe masters who have seen it all pass before them but have learned the hard way how to make a stable computer environment that stays up, even on cruddy mainframe technology. If their attitudes were adopted by people fluent in today's fantastic systems, all people would benefit.
“Our opponent is an alien starship packed with nuclear bombs. We have a protractor.” — Neal Stepnenso
Wow, what a post! I typed the whole thing into teco and it played the Star Spangled Banner on my DECwriter III !
MAN SHOOTS ROVER!
Most of the mainframers that I have worked with are nine to fivers and many didn't have a PC at home or do much more than check emails when they do. They don't code routines at home to expand their work capabilities and many think that if it doesn't weigh 6 tonne and need 10 keepers and an air conditioning plant, you can't call it a computer. Most depend on the fact that their arcane skills aren't taught any more and that's all the job security they need.
Too lazy to create a sig...
I even worked with two Mac guys with beards
No, no... those are called "goatees".
No sig
Whatever. Unix has been on 64+ CPUs for a long time now. Is anyone selling an NT machine that comes close?
"A language that doesn't affect the way you think about programming, is not worth knowing" - Alan Perlis
The Windows admin washed his hands, then pulled out twelve paper towels and thoroughly dried both hands up to the wrists in two seconds flat.
The Unix admin took out one paper towel and very carefully, using every bit of dry towel, dried his hands perfectly in under one minute.
The Mainframe admin breezed through without stopping to wash his hands at all.
"Somewhere along the line" he said, "we learned not to piss on our fingers..."
Do not mock my vision of impractical footwear
Unisys sells 32 CPU windows boxes, HP sells up to 128 CPU Superdomes capable of running Windows 2003 Datacenter edition, and there's probably some others I'm not aware of. Since quite a few companies have high end systems using Itanium 2 processor's there's very little reason not to support windows server, it just might sell some more units =)
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
... in windows that is true, threads are better period. That is NOT because of process vs threads its bceause of how windows handles process and threads. threads are efficent and multiple processes aren't.
3 .0/0935.html
as said by someone who knows more then i do:
"There are no threads in Linux.
All tasks are processes.
Processes can share any or none of a vast set of resources.
When processes share a certain set of resources, they have the same
characteristics as threads under other OSes (except the huge performance
improvements, Linux processes are already as fast as threads on other OSes). "
read
http://www.uwsg.iu.edu/hypermail/linux/kernel/010
the one that is faster and better for a task depends on: programmer skill, style and design. Do you want shared memory, harder debugging, for a bit of a speed increase, or a clean modular design, simple processes working togeather. smaller project sizes, at possibly a bit of speed cost. Its all about trade offs and in linux you can pick either so its all comes down to the programmer usualy, in windows threads are the only way to go,
Now to you last paragraph, windows is was NOT designed to be SMP, and if it was it sucked ass at it. linux has had SMP support for a long long time. And the fact windows is 4CPUs at most, and linux is running on 64+ CPU machines all the time, and on huge clusters of 1000s of boxes shows me that linux was designed pretty well.
And as always linux is ahead of the curve overall then windows (in the kernal) at all times. and runs on more system.
and the other reply so far is from a total idiot.
In NT4 and earlier, those systems weren't there (WSH came out around Option Pack 2, right? It's been a while). However, up until recently, the majority of Windows Network systems were NT 4.0. The W2K+ Scripting environment is quite impressive (I've been doing my first Windows work in a while recently, although mostly Excel/VBA programming, but played with the scripting capability for fun), and it has come a long way.
When I worked a decent sized MS Partner, the MS Way was "point-and-click." They were going to do a 10,000 user migration by hand, because that was the MS Way. I grabbed the NT 4 Resource Kit and whipped up some Batch scripts to do the parsing, and the Windows guys were amazed.
Windows has some very intelligent scripting, buts its somewhat hidden because the NT 4 Days, which weren't short, but caused a problem. Older PC guys knew Batch scripting, which kinda disappeared in the NT 4 days because the tools weren't readily available (buried in the Resource Kit meant that you couldn't count on them being on the machine). The newer object-oriented programing method is cool (and absolutely preferable to parsing text streams, which as you said depends on an unchanging text output from a program, which is very constraining), but you need a new generation of Windows Geeks.
Unfortunately, hacking on Windows is about as "cool" as a Mac was 10 years ago, so your computer geeks just aren't learning it. This doesn't change the fact that good admins are critical, but there is a perception problem. Just like Novell became perceived "dead" because nobody saw it because the machines didn't crash.
The WMI/AppleScript approach (as in, thick self contained apps that are callable) is perfectly legitimate.
The other problem you have here is what happened to the MCSE in the late NT 4.0 days. When I was just finishing my MCSE, all the MCSE study guides were coming out... teaching to the test, and MS didn't upgrade the tests fast enough. Stuff that took me weeks reading the NT 4 Resource Guide was available in a condensed 4 hour book. Combine that with the MCSE Courses, that taught to the test, and the whole industry get messed up. People hired cheap "paper" MCSEs, and people got used to Admins not being able to program. Finding a Windows Admin that truly gets it is rare, because there is too much dependance on unknowledgable paper-admins, so people assume all Windows Admins suck.
Alex
Later that afternoon, the Mainframe admin got a horrific case of E.Coli poisoning from the handle of the urinal.
No, I don't trust in god. He'll have to pay up front, like everybody else.
What do we all need to know to get along in each other's worlds?"
What is needed is open specs on anything that enters or leaves the machine whether it be a file, protocol, or hardware handshake.
The biggest area's of contention are printers that won't work, this sound card, video card, input device, etc won't work because of no published standard of how to talk to it. We need the end of closed drivers, files and secret drivers.
Open standard items work great on all platforms. Take for example Ethernet and TCP/IP. The cable is standard as well as the low level signals. Plug in a cable, follow the spec for the address and it works.
Anything that uses TCP/IP on Ethernet also just works.
Plugging in my printer into a Centronics port takes care of the low level hardware connection, but there are big problems after that. The printer box should not require anyting beyond a Centronics, USB, or other standard connection. The idea of Requires Windows 2000 or Windows XP is for the birds. Saying it is Postscript is 100% OK. I can connect that to anything with the proper hardware port (Centronics, USB, Ethernet, Firewire, etc.) that supports Postscript.
The truth shall set you free!
I'm a mainframe sysprog but I've coded on Unix & Windows. I'm also rather young (33) for a mainframe sysprog. Here are the differences.
The first difference is the difference of work running on a system. Unix & Windows development typically takes place on dedicated machines. The changes are then applied to a separate production machine. On a mainframe development & production are often the same LPAR (Logical Partition) or the same physical box. Because of this development gets the low priority. If you run out of juice on a Unix/Windows box you either get a bigger one or you cluster them together. In the mainframe you either redesign it to run more efficiently or you start shelling out $$$ for a bigger machine. Normally your only choice is the redesign.
Software on a mainframe is horribly expensive and the faster the machine the more it usually costs. This is an old way of spreading the pain of software development. The big guys pay more because their machines are faster but the smaller guys get to pay less. Imagine if MicroSoft decided to charge a lot less for Office if you ran it on a P5 instead of the newest processor? Some software on Windows is licensed by the CPU, but I've never heard of the speed of the CPU being a factor. Do you think you'd get that fancy new PC if the software would cost 10x as much?
On a mainframe software development is a slow process with lots of checks along the way. Nobody just "slams in a change" unless they are either 100% sure it will work and it fixes a critical problem that is impacting business, or they want to be fired. Banks frown heavily on downtime. Unix & Windows systems seem to be more tolerant of this (with the odd exception being email - how email became the most important application is beyond me).
Once you develop, debug, and get a mainframe program running you can usually forget about it. There are programs running on mainframes today that haven't changed in 30 years. That is a pretty good return on investment. I've dealt with both and it seems to boil down to "pay me now or pay me later". Installing stuff on a mainframe take a lot of up front work but if you do it correctly you can expect it to work well when you are done. Windows programs are easier to install and develop but you have the constant reboot issues, memory leaks, and just plain annoying mysteries to deal with.
Mainframes (in my opinion) have far far far superior system diagnostic tools. If a program is running slow I can determine if it is CPU, disk, database contention, or any other resource shortage. This is mainly because there is so much running on any given mainframe that system diagnostic tools need to be very good. The tools on Unix and Windows are good but they don't need to be as complete because the environments are far less complex.
Program debugging tools on a mainframe can be awful. Interactive debuggers are the exception, not the norm. They tend to take up CPU which drive up software costs which the finance department hates. I've seen good interactive debuggers but they suck CPU and make the finance department hate you.
Batch controls on a mainframe are far superior to Unix or Windows. This is mainly because the mainframe started life as a batch system. Once you understand and master JCL it is really a good system. Batch on Unix and especially Windows is more of an after thought. You can run batch, but the tools to monitor failures, schedule dependencies, and validate results are not as good.
A programmer must know how a program is going to run on a mainframe long before you run it. You need to know how much disk, CPU, and memory you need and how man lines of output you are going to use. If you exceed this by too much your program will be automatically canceled. This is because you are not the only one using the system and if you exceeded what you said you needed your program could have a problem. That can be painful but it stops program loops if done properly.
The "just reb
http://www.straightdope.com/classics/a4_220.html
Keep washing those hands, kids!
Unixheads seem to claim that it's perfectly admirable to hack around the ASCII format for everything because it makes it easier to debug, whereas all I see is wasted entropy and bandwidth.
Wait until you have to troubleshoot issues with SMTP, POP3 and the like, then you will absolutely love the fact you can simply fire up telnet, connect to a server and manually test things by typing the protocol handshakes in. Not only are they all ASCII, they are easy to remember and make lots of sense.
Take it from this SysAdmin/Programmer, you'll never want to go back to a binary protocol again.
Years ago, I worked with a grizzled old mainframe veteran. Let's call him Dan. Earlier in his career, Dan ran the datacenters at American Express and FedEx. Dan knew big iron.
One day, a few of us were ooh-ing and ahh-ing over the latest whiz-bang quad-Alpha box. Dan just laughed, shook his head, and said: