Domain: ethz.ch
Stories and comments across the archive that link to ethz.ch.
Comments · 364
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Re:You don't ship test code
Requiring that all checkins be accompanied by unit test code is ridiculous because two developers working on the same code will need to update not only the code itself but also any test cases that rely on the behavior of the executing code.
The solution to that, of course, is to integrate test definitions into the code itself so that it all gets updated together. As a bonus your API documentation is more precise and gets updated along with the tests and the code. You can then push a button, walk away, and have an automated testing system fully exercise your code. And yes you can have all of that for Java if Eiffel isn't to your taste (though it might be worth having a second look at Eiffel).
In other words, yes if you want software with lower defect rates you should expect developers to update their specification (and documentation) of how they intend code to be used and to work at the same time that they update the actual code. If you want to specify working code by having it pass a separately written unit test, fine; but that's not the only way, nor is it always the most efficient. -
But
Real Men Don't Click anyway...
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Re:Actually, USGS did detect seismic activity
Interesting. But,
...
I wonder why the Taipei, Inchon and Japan stations, which are also quite close, don't show any seismic activity.
Also, the seismographs for the Pakistan test in 1998 look different than the Guangduong station data. -
Re:Easy to write a negative book
Any ass monkey can right a book of criticisms... I would like to see his attempt at a software development methodology that is better.
It is highly unlikely that there will be a particular methodology that magically makes things better, but certainly there are things you can do to make things better. Two major hurdles in software quality are "building the right product" and "building the product right". That is, is what you are planning to build what the users want, and is what you're actually building the same as what you're planning. There's no magic methodlogy, but spending some time thinking how to best answer those questions for your particular piece of software can go a long way toward lifting the quality. The first question, ultimately, is the hardest - working out what you need to build involves wheedling the details out of the customer. You can do things like acceptance testing, or try an agile rapid feedback approach, but that isn't always applicable, and it isn't necessarily going to get you the right answers.
The other side of the issue is a little easier, presuming you're willing to expend a little effort. At the most basic level there is testing - whether that is direct testing from a testing department, unit testing, or automated random testing (like quickcheck or AutoTest). Alternatively you can step up to extended static checking tools like ESC/Java2 or Spec# which use automated theorem provers to try and find potential errors, effectively testing all possible inputs - they can't always find errors, but they can find a great many that testing won't. In the end though all of these, even the most basic testing, require you to be able to specify what it is you are trying to build (see the first paragraph). The more preceisely you can specify that, the more powerful the testing you can do to verify that you're building what you intend. That means the quality of verification is up to the quality of the validation - how well you know whether you are building what you want, depends on how well you know what you want to build. -
The original article (German)
The original article (with some more information, but in German) is here: http://www.ethlife.ethz.ch/articles/neuerantrieb.
h tml -
Re:Still Mechanical Conversion to EnergyFuck you. I, like the story submitter in their summary, refer to the Swiss device as a "turbine" in shorthand for the essentially interesting part of the device:
The matchbox-sized motor generates the equivalent of 100 watts, including the power electronics interface, and has an efficiency of close to 95 percent. Powered by a gas turbine, one tankful of fuel drives the generator
If I didn't read the damned article, where did I get their 95% efficiency claim, or the rest of the details of the device and its limits?
While the original article that article merely excerpts further refers to the device as " These micro-gas turbines".
Why don't you try reading the damned article yourself, and my damned post, to offer some damend useful input, rather than your annoying nitpick? -
Re:Give grey listing a try...
I second greylisting, I've had pretty good spam control but I installed postgrey a couple of weeks ago and spam has come to a near standstill.
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Re:Great article!
To the poster with their "there is only one C"; Horsefeathers. That there is Only One C explains why every C program I have is a twisty little maze of #ifdefs, often for minor differences in machine/compiler combinations, and as likely to break after a compiler upgrade as continue to build. It continues to exist only because it's suitable for assembly-language-type functions, such as OS kernels, which means it ships with every unix out there, and is taught to unsuspecting comp-sci students because it came free with the OS. It's amazing that after the problems of the past few years, including buffer-overrun exploits, memory leaks, etc, caused by C's unsafe, seat-of-the-OS memory handling, that people continue to defends its use as a general purpose language.
The OP may be trying to be funny, but in fact a modern Fortran (F90/95) is easy to do string manipulation in, has dynamic memory, is type-safe, and is arguably a much higher-level language than C. (on the other hand, F90/95 bears a curious resemblence to Ada, but we'll let that slide). Memory aliasing isn't nearly the issue it is for C programs, which is why Fortran still out-performs C/C++ on any modern architecture, as long as you're using a competent compiler. (i.e. I don't want to hear about how slow your G77/GFortran programs are; they're great tools, but they're primarily Fortran Lints (flints)). Where Fortran fails is that is has the same name as a particularly onerous language from the mid-60s, known variously as FORTRAN-IV or FORTRAN66. If it was named differently, such as Cerulean, for instance, you'd complain about its verbose, Python-esque syntax, with Begin and End, rather than { and }, but you'd grudgingly learn it, write interfaces to libraries, start new projects in it, and treat it as an appropriate tool. Flame wars would break out here as the Cerulean programmers made fun of the Java-weenies, because their language is byte-code interpreted, and doesn't have matrix operations built in as primitives (how can you do quick 3d graphics without matrix ops). Because of the antique name, you picture a black and white room full of guys in white shirts with pocket-protectors and crewcuts, smoking while they load pounds of manila cards into the keypunch.
Back when we were in college we used to comment that C was a step backwards, as in terms of being a high-level language it ranked right up there with VAX assembler. Let it go. Use C++/Objective-C/Java if you're obsessed with line-noise syntax, or move on to Eiffel http://eiffelsoftware.origo.ethz.ch/index.php/Down loads/ /Ada or even SmallTalk http://www.squeak.org/ for new work. -
Re:Only ?
These guys got 5385 km/l (that's 12,666 MPG !) in 2005.
Divide by Zero. ERROR! ERROR!
According to their site, that car doesn't run on gas at all: http://www.paccar.ethz.ch/technics/index
Maybe they're doing something crazy, like counting a small ammount of lubrication oil... -
Only ?
http://www.paccar.ethz.ch/news/index These guys got 5385 km/l (that's 12,666 MPG !) in 2005.
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Autotest
A tool not listed is autotest http://se.inf.ethz.ch/people/leitner/auto_test/ which makes use of Eiffels contracts. I did use it to some degree and it can realy help to find some errors.
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Re:Been there done that!
For some reason the thought of throwing a penguin through a window made me chuckle just a little bit.
This is good entertainment, too: http://n.ethz.ch/student/mkos/pinguin.swf -
Java is already fragmented
Java is already fragmented. The result of open sourcing Java will actually be consolidation, i.e. killing of competing VMs. And a huge open source test suite will greatly benefit all surviving JVMs, which is a good thing.
How can you not see this?
Javas problem is not that it might get fragmented, the problem is that it IS fragmented. Do something about it! Let Java free! -
Re:disambiguation
Is it just me, or does this look quite a bit like Nikolaus Wirth's Oberon system, which also mainly consisted of a mouse-driven text editor?
(It's concept and usability also sucked galaxy clusters through nanotubes when I had to use it for doing exercises during my computer science studies, but that's a different story - although I can't believe that ACME would be much better...) -
Postfix + Postgrey + Spamassasin != Lots of spam
People at my company regularly received 80 spam emails per day when I started (Exchange 2000). I promptly installed a Linux mail gateway with Postfix as the MTA, Postgrey and Spamassasin. The very next day I had people coming to ME, asking me if I had changed soemthing on the mail server, because they only had a few messages in thier mailbox, rather than thier usaual dozens.
I'm telling you, you cannot count on AOL, gMail or whoever to control spam, and in my opinion, filters at the client level are stupid. You STILL recieve the spam, no matter what folder it goes to!! Host-based filtering is the ONLY way to go these days.
Works like a CHAMP too! Dns checks, RBL checks, destination controls, greylisting - and the last line of defense, Spamassasin for the heuristics scanning. After all that, there is no need to have client level filtering!
Btw, if you have never heard of Postgrey, it works AWESOMELY!
http://isg.ee.ethz.ch/tools/postgrey/
Contact me if you want some config examples, I'd be happy to help!
-Ponga -
Re:Well
here, you lazy fucker.
http://www.divx.com/divx/mac/playback/
http://n.ethz.ch/student/naegelic/
http://www.3ivx.com/download/index.html
all available as quicktime plugins. -
Re:e:New Mac mini video chipset! Made for Home the
Front Row plays anything Quicktime can. And there are codec plugins for Quicktime on the PowerPC side to handle pretty much everything. Below is a list of codecs I used on my PowerPC Mac Mini to play back pretty much everything I had except an occasional Real Media file. Keep in mind these have to be coded specifically for Intel to work on the new Mini properly.
Divx 6: http://www.divx.com/divx/mac/download/
XVid delegate: http://people.ee.ethz.ch/~naegelic/download/
3vix: http://www.3ivx.com/download/macos.html
AC3/A52 decoder: http://sourceforge.net/project/showfiles.php?group _id=83360
WMV Decoder for Quicktime: http://www.flip4mac.com/wmv.htm
Quicktime MPEG2 decoder, $20: http://www.apple.com/quicktime/mpeg2/ -
Oblig. Answers
I'm involved with a project that is looking to develop an online community for technology oriented business customers.
Sell your idea to ebay, they might like you. (and the highest bidder wins!)
If you could develop an online community to encourage collaboration and information sharing, what features would you want included?
That's easy, BitTorrent.
How would you go about including features that are widely available in other places (weblogging, message boards, wiki) and generating buy-in from customers.
1) Visit homepages of said OSS
2) Get the sources
3) Right-Click Ctrl-V
4) Get headache integrating code from multiple projects^W4) Discover 'magical' missing libraries^W4) Consider rewriting everything with existing code as reference^W4) Give up^W4) ????
5) Profit! -
Photoshop for UNIX
I brought this up last week in a different discussion, but not only did they have a version for SGI at one point, they had a version for "UNIX" in the form of SunOS/SPARC. It was for SunOS 2.x and I think it was around Photoshop 3 or so.
This place has a PDF version of the Adobe product brochure:
http://computing.ee.ethz.ch/sepp/photoshop-3.0.1-s t/photoshopSun.pdf -
Academic skype scare?
I have worked for a Max Planck Institute in the past, and I must say that a society-wide policy on something like Skype is really unusual for the Max Planck Society. First of all, it engages in fundamental research, so the institutes usually have a very easy-going, academic attitude -- don't regulate too much, let the members get away with a lot, as long as they produce results. And the institutes are usually very independent on each other, they do not share any IT services or network connections (internet connectivity is provided by the DFN, the German research network). So what one institute does with its IT doesn't concern any other institute.
So, what might have provoked the MPG into this policy? I could understand a ban on p2p -- the MPIs are usually part of a university, there are lots of student assistants, also in the sysadmin groups, so there is lots of filesharing going on. I could understand them banning filesharing, because (beside being illegal) it sucks an ungodly amount of bandwidth, in addition to the bandwidth the institutes have to use for their work (because have to exchange huge chunks of research data, or operate huge mirrors.)
But why Skype? The only explanation I can find is last year's Skype scare from the Swiss Federal Institute of Technology in Zürich (see this article). They found out, ooops, Skype is a P2P program, it uses our bandwidth for routing calls by other users, quick, shut it down! But would that be enough for a ban on Skype?
I don't really believe the cited reasons (sensitive data, misuse of MPG resources, etc.) It's usually up to the individual institutes (and their sysadmin groups) to devise a security policy and make sure that MPG resources are not misused.
So
... I left the MPI three years ago, so I'm not aware of the current state of the MPG. I'd like for someone to shed more light on this issue. It's really unusual.Regards, Felix.
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Academic skype scare?
I have worked for a Max Planck Institute in the past, and I must say that a society-wide policy on something like Skype is really unusual for the Max Planck Society. First of all, it engages in fundamental research, so the institutes usually have a very easy-going, academic attitude -- don't regulate too much, let the members get away with a lot, as long as they produce results. And the institutes are usually very independent on each other, they do not share any IT services or network connections (internet connectivity is provided by the DFN, the German research network). So what one institute does with its IT doesn't concern any other institute.
So, what might have provoked the MPG into this policy? I could understand a ban on p2p -- the MPIs are usually part of a university, there are lots of student assistants, also in the sysadmin groups, so there is lots of filesharing going on. I could understand them banning filesharing, because (beside being illegal) it sucks an ungodly amount of bandwidth, in addition to the bandwidth the institutes have to use for their work (because have to exchange huge chunks of research data, or operate huge mirrors.)
But why Skype? The only explanation I can find is last year's Skype scare from the Swiss Federal Institute of Technology in Zürich (see this article). They found out, ooops, Skype is a P2P program, it uses our bandwidth for routing calls by other users, quick, shut it down! But would that be enough for a ban on Skype?
I don't really believe the cited reasons (sensitive data, misuse of MPG resources, etc.) It's usually up to the individual institutes (and their sysadmin groups) to devise a security policy and make sure that MPG resources are not misused.
So
... I left the MPI three years ago, so I'm not aware of the current state of the MPG. I'd like for someone to shed more light on this issue. It's really unusual.Regards, Felix.
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Photoshop for UNIX -- Been there...
Not sure if you're aware, but there was, once upon a time, a version of Photoshop for UNIX in the form of Sun Solaris. I think the last version (and maybe the only) was 3.01.
There's a PDF version of the product brochure here. (It's 1.5MB and hosted out of some university's server in Switzerland. If you're feeling kind, here's the CoralCache link of same.)
I'm curious what form it was distributed in -- I assume just binaries ... but if Adobe ever felt like bringing that one back from the dead, even if it was just recompiled as x86 binary-only, if they didn't charge an arm and a leg I think there would be a serious market for it. Even Photoshop version 3 is nothing to scoff at -- it had full CMYK, TWAIN import, and pressure-sensing tablet support, to name a few. And this was designed to run on a SparcStation 2 with 32MB of RAM; I don't care how much optimization you lose by compiling it for x86, you're not going to notice on a modern machine. And given that they had versions for Win, Mac, Solaris, and SGI, I'm betting that the codebase was pretty portable.
Ah, well. A man can dream... -
Re:IronyIt's ironic that in setting out to 'solve' spam, Microsoft all but destroyed the momentum around SPF
I am now seeing SPF records for fully 1/3 of incoming external email on my medium-sized company's mailserver. Of course I also greylist (which virtually eliminates the crap fom zombie PCs), but of the mail that makes it though the filters, the percent using SPF is slowly but surely climbing.
Do you know of some evidence that shows that SPF adoption is slowing?
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Re:Powerwatch is a company, not a nonprofit.
This is without doubt the strongest, and was published in May 2004:
Risk Evaluation of Potential Environmental Hazards from Low Frequency Electromagnetic Field Exposure Using Sensitive in vitro Methods
A project funded by the European Union under the "Quality of Life and Management of Living Resources"The entire report in full is available at this link: www.itis.ethz.ch website
One of the biggest problems with these studies is they often don't look at quite the same thing the second time round... for example with phone exposures sometimes they increase the power beyond that expected for mobile phones, often when not using actual handsets they do not use the exact same waveform of the phone - Maybe this is important, maybe it isn't, but if we are testing phones we need to make tests as accurate as possible, when we don't understand the mechanism we cannot to assume that we know what effects changing these settings will do. A study showing no association, unless it looks at exactly the same thing, does not invalidate a positive association.
Who knows, hopefully all of these positive associations will be a red herring, but a lot of work needs to be done before we'll know!
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Re:Similar to the video game course offered at UCS
And similar to the course at the ETH. (To get used to the Eiffel libraries)
More games here:
http://se.inf.ethz.ch/download/games/04/
http://se.inf.ethz.ch/download/games/05/ -
Re:Similar to the video game course offered at UCS
And similar to the course at the ETH. (To get used to the Eiffel libraries)
More games here:
http://se.inf.ethz.ch/download/games/04/
http://se.inf.ethz.ch/download/games/05/ -
In case you are a Programming Languages Guy
These folks have a formal semantics of C#:
http://www.ti.ethz.ch/rs/
For those who don't see the point in having a computer language if you can't say, precisely what statements in the language mean. -
Re:Love it
"...a high-level garbage-collected language is a step too far..." Why not a systems-level statically compiled typesafe garbage-collecting language? There is such a thing, you know. There is even a modern OS running on x86, all without any C at all. (Ugh! Pointer aliasing!) It is called Bluebottle. And -- you can skin the GUI by editing an XML file! Woohoo! http://bluebottle.ethz.ch/
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Try these tools
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Obligatory screenshots.
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Use MRTG
Can anyone point to a recent study that would support my theory, and help me convince my management that we just plain need more bandwidth?
The only study you need is a report from MRTG. Configure it and have it start graphing your network utilization for your E1. After a week or two you'll have several pretty graphs that can show your management exactly how saturated your connection is. Also, look at installing a caching proxy, such as Squid. -
Automate System Rebuilds?
No, this isn't for every situation. Common hardware is a must (or at least a real help). But, it does neatly solve other common issues, like system builds.
A freind of mine does just this on his home system about once a month (well, and at work...as he says, we're not in the business of installing an OS by hand anymore). I'm going to take the same plunge. Pick an automated system rebuild method, test it, build new systems with it and rebuild your systems on some sort of regular basis. There are lots of caveats to the Microsoft methods (ADS/RIS... single partition systems, you need BOOTP, blah blah blah). And, the image-based methods can be tricky (Ghost? Oh come now). Other options like nLite might help, too.
It may not be what the doctor ordered, but it will simplify your life when you need to build a new workstation. And, if one gets pokey beyond the reach of the other tools mentioned, blow on a new image. Plus, if you're using XP, you can use folder redirection to keep the user files someplace else, so you don't neccesarily have to rely on draconian policies regarding where they should save files (well, you can't let them save files just anyplace, so a few policies may be in order).
Is this the ultimate insult that the best way to manage Windows workstations is to automate reinstalling them? Well, maybe, depending on your viewpoint. But, it is what it is, so we build automated methods to learn to live with the limitations.
Humbly submitted, here are some of my bookmarks on the subject:
http://www.cmu.edu/computing/andrew-windows/andrew -ris-server.html
http://ani.sourceforge.net/
http://www.autoitscript.com/autoit3/
http://support.microsoft.com/default.aspx?scid=kb; en-us;299441
http://www.livejournal.com/users/lotso/1863.html
http://isg.ee.ethz.ch/tools/realmen/
http://www.microsoft.com/windows2000/techinfo/howi tworks/management/remoteover.asp
http://www.microsoft.com/whdc/archive/risover.mspx
http://www.microsoft.com/technet/prodtechnol/windo wsserver2003/library/TechRef/3983c4a4-e6ff-4664-84 25-28ec740474b1.mspx
http://unattended.sourceforge.net/
http://www.windowsitpro.com/Articles/Index.cfm?Art icleID=7109
http://www.microsoft.com/technet/prodtechnol/windo ws2000serv/evaluate/featfunc/intmiror.mspx -
checkout RRDtool
The ability to produce real time plots of the data during logging would be an advantage. Buying a new logger would not be a problem.
In the open source world, I would look for small tools which satisfy your need when setup together in concert.
For producing real time plots, my choice would be RRDtool:
http://people.ee.ethz.ch/~oetiker/webtools/rrdtool /cheers.
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MRTG?
I am not sure if this is entirely what you are looking for but MRTG is an open source SNMP monitor. It may work in your situation if the logger supports snmp. It can be a ittle tricky to use so recomend looking for configuration tools or the configuration file help on the MRTG website. On the plus side it will create 5 real-time graphs updated every x minutes for each variable you monitor, going all the way back to daily averages for the year. It works on windows xp and is easily migratable because it is written in PERL.
Enjoy and i hope it works -
How do I screw up a network?
By touching it. There's always an assistant named Murphy looking over my shoulder, but she usually waits until I'm in the shower or leaving on vacation before "helping".
Your question is really "How do I introduce layer 1 and 2 problems into my home LAN, since all layer 3 routing is limited to a NAT box with a single default route?". The lower layers are a good place to start, since half of all your problems come from there, save the routing problems for a future ask/. question.
Others have already pointed out the joys of having dueling DHCP servers, subtly mis-configured DNS servers, overlength cables and the like. Keep an eye out for others throwing out bad ethernet cables with broken catch-tabs, frayed insulation, sharp kinks or intermittent wiring, and put them into critical places in your network. They may not fail right away, but will wait until you host a lan party at your place or you have a few hours to get a report done. Her name is Murphy, she's a bitch and she'll gladly pay you a visit when you least want her around.
Start to learn what kind of traffic is on your local network. Get ethereal, snort and ntop running, and see what the packets look like. Chances are you'll find some things that look suspicious, you'll learn a lot by figuring out how DHCP handshakes work, how often ARPs happen, what other protocols are on your net besides IP. Since you are running a BSD, you can pretty safely put the box on the outside of the firewall (it probably is the firewall) and watch all the constant crap scanning the internet. That's a great way to learn how to tune firewall rules by hand, and you will break things along the way.
To really start to learn how layer 2 networking almost works, grab some old cisco kit off of eBay. I've seen 2900 switches for US$20. Plug something slightly pro into your network, start simple, just get a cheap used cisco/hp/3com switch off eBay that can do 802.1q vlans, spanning-tree, and snmp. Your BSD ethernet card can be configured to do .1q, so there is a lot of learning there by creating multiple separate vlans, one for each machine. A single router and switch with 802.1q vlans can make some pretty complicated networking topologies without massive amounts of wiring. Then you can break your network by plugging a crossover cable into two ports and watching spanning tree open up one of them. Bonus points if you create a topology where by creating a spanning tree loop, your main gateway or server port is the one that goes into blocking mode (you need a minimum of two switches to do that).
To break things in subtle and non-obvious ways, try changing your address ranges from the usual 192.168.0.0/24 to something unusual like 172.31.255.16/29, doing the netmask/subnet/broadcast calculations in your head for practice. Then misconfigure the netmasks on each device, notice how one machine can ping another, but not the other way around. Try building multiple separate segments rather than multiple subnets on a single wire, this will force traffic to use your router, and really show netmask problems more clearly.
To really break things, instead of using reserved RFC1918 addresses behind your NAT box, use a public network range like 66.35.250.0/24. Sure, it will break one major site, but you shouldn't be wasting your time there :-)
Since you already have a BSD running, do you leave it on 24/24? If so, its time to start loading up the real tools like cacti, nagios, and smokeping. It helps if you have an SNMP capable switch on your network, but configuring your own SNMP can be quite a learning experience as well. With graphs showing what is happening on your net and the internet over time, you will start to see the cycles of congestion every evening and maintenance times every sunday at wee hours. The most frustrating problems in networkin -
This is ok for firefighting, but...
Surely the job of a sysadmin is to get on top of everything, and then to be proactive in managing their systems. So, for me, things like Big Brother ( http://bb4.com/ ) and mrtg ( http://people.ee.ethz.ch/~oetiker/webtools/mrtg/ ) are the most useful. which editor you use is just a matter of preference. Personally I'm with the author ( and with telnet too ), but that's after 20+ years of picking up bad habits
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Re:Parallel Topic: Win32 targets
Actually there is people doing just that. Check these: GNUstep and Gorm on Windows. See the screenshots of train data exchange software and train simulation software.
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Re:Parallel Topic: Win32 targets
Actually there is people doing just that. Check these: GNUstep and Gorm on Windows. See the screenshots of train data exchange software and train simulation software.
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Re:Asgard Shielding Technology
Well, it looks like we will actually be getting some asgard shielding on the ISS afterall! Woohoo!
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POstfix + Mysql
Look at postfix + mysql
http://www.sweeney.demon.co.uk/pfix_imap_virtual.h tml
Mostly, U will need a cluster for everything.
If you are seeking for a all around opensource, start with this link, later, to use LVS, the tool for makeking load balancing clusters go here:
http://www.linuxvirtualserver.org/
And if you really are looking for a opensource cheap software costs (not very cheap tco) also you can build your OWN san with ata over ethernet:
http://sourceforge.net/projects/aoetools/
And for webmail a usefull but also ligth interface:
http://www.squirrelmail.org/
With all the licence cost savings, you can Invest a lot of time, and have a fair amount of flexibility.
Sendmail inc, has high availability solutions:
www.sendmail.com
Also, you can spend a lot of money and buy a very bit IBM machine with lots, and lots of lotus notes licenses, with that kind of money spent, you can put IBM at your knees if a lawer makes a good contract..
Also, to complete the solution you can setup nagios and mrtg for monitoring.
http://www.nagios.org/
http://people.ee.ethz.ch/~oetiker/webtools/mrtg/
I think, to setup the hole thing, U will need, like about 50 good servers, (maybe u can try IBM openpower with virtualization, it IS a risc CPU), and like.. humm.. a month of technical tests...
The mysql backend will give you centralized administration, LVS will provide scalability and good servers will give you uptime...
And if EVEN you like, you can make a Linux Routers using sangoma hardware:
http://wwww.sangoma.com/
Everything can be done with Linux by now... The cuestion is how much responsability do you want to have regarding the stability, and overall functionality of the solution.
IBM, HP, RedHat, SuSe, and ANY Linux Consulting firm would be interested in having you as a success history.
Good Luck, and May the Source be With You -
Re:I knew something was up...
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useful things...
Software:
http://people.ee.ethz.ch/~oetiker/webtools/mrtg/
http://www.nagios.org/
Hardware:
Two high resolution projectors and screens to project them on. -
Re:Word from Chicken Little
Um, I just ran a tiny bit of calculation with info from the top of my head, which indicates that your 500 exaJoules/year is a 0.1% effect compared to solar irradiation. the diameter of the earth is like 12,750 km; that squared times pi/4 (area of a circle) is like 1E14 m^2 (working in orders of magnitude here). lets guess that of the 1300 W/m^2 that hit the earth, all but 100 W/m^2 is reflected, the rest absorbed.
Our calculation now is 100 W/m^2 * 1E14 m^2 = 1E16 J/s. 1E16 J/s * 3600s/hr * 24hr/day * 365days/year = 4E23 Joules/year = 400 zettajoules/year. this makes the the 500 exajoules/year a little more than a 0.1% effect. Humanity's effects are doubtless huge in an absolute sense, but compared to our favorite nuclear furnace, we aren't heating the atmosphere. What we are doing, is adding to the greenhouse effect, which means the energy that the sun irradiates us with, gets lost to space at a slower rate than it did 200 years ago.
Admittedly, I could be off by an order of magnitude in either direction, but my guess is that the Earth's atmosphere is less than 90% reflective of infrared light. Also, I might've done the real calculation of blackbodies exchanging heat across space, but this is meant more as a sanity check than rigourous math. Please tear my thinking apart; I'll think better for it.
diameter of earth: http://www.pubquizhelp.34sp.com/sci/planets.html
solar irradiation intensity: http://www.tfp.ethz.ch/Lectures/pv/irradiation.htm l -
Australia has had "problems" with speed cameras...From Risks Digest (which ought to be mandatory reading for anyone developing software or hardware):
Millions of lost revenue from faulty speed cameras
Bertrand Meyer
Sat, 01 May 2004 14:44:42 +0200Given the attention this story has been commanding in Australia, I was surprised to find no record in RISKS. The country is proud of its strictness in enforcing speed rules, sometimes fining motorists for driving one kilometer above the posted limit (however absurd that sounds). The state of Victoria has numerous speed cameras. Last year their accuracy was questioned after reports that a truck with a maximum speed of 140 km/h was caught traveling at 164 km/h, and other similar incidents. After the first such report the Assistant Commissioner said (Melbourne Age, 11 Nov 2003):
"There's no evidence to support that any of the other cameras are malfunctioning [...] in any other way,"
but he later had to change to:"It's embarrassing for everybody... Technology is technology and I think we have had indications where it doesn't say the right thing."
The state government then ordered tests of all the cameras in the system, and had to suspend fines from all fixed cameras. According to the Age of 29 April 2004, the problems were supposed to "take six weeks to fix" but:almost six months after the State Government suspended the issuing of fines from Victoria's fixed speed cameras, problems with the cameras are still unresolved [...] A State Government spokesman confirmed yesterday that the 47 fixed cameras were still under review. He was unable to say when the issue would be resolved.
More than 40,000 fines notified to motorists have been suspended until the results are in. This represents a total sum of over six million Australian dollars.For details:
http://theage.com.au/articles/2004/04/29/10832245
1 6563.html (30 Apr 2004)http://theage.com.au/articles/2004/04/28/10831035
5 1024.html (29 Apr 2004)http://www.theage.com.au/articles/2003/11/10/1068
3 29487082.html?from=storyrhs (11 Nov 2003)Bertrand Meyer
ETH Zurich / Eiffel Software
http://www.se.inf.ethz.ch/ -- http://www.eiffel.com/ -
Re:AdviceI've set up Postfix, UW-IMAP, and Squirrelmail for my own personal email server and I am by no means an expert sysadmin. Setup was fairly straightforward.
I also installed the Postgrey policy server for Postfix and haven't looked back since.
If you have any Linux experience you ought to be able to handle the configuration. If I can do it anyone can!
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Smokeping
Give Smokeping a try. Smokeping:ping::MRTG:bandwidth.
http://people.ee.ethz.ch/~oetiker/webtools/smokepi ng/
It shows latency, loss, and jitter in a combined easy to read graph. After using it for a while, you can spot many normally invisible network anomolies on these graphs long before they become visible to users. They're also great for post mortem analysis.
They don't have anything to do specifically with VoIP, but I think they're invaluable tools for any network admin. -
Re:Here we go again...
> There is a huge difference here. With Muslims, the religous leaders are not standing up and preaching terrorism is bad.
Hmm. I must have imagined this news report for the other day where "The Fiqh Council of North America (FCNA) released a fatwa, or Islamic religious ruling, against terrorism and extremism last week" -
Image library?
ImageMagick is under its own license, but I don't think you're going to run into any trouble using the ImageMagick library in your application. The 'image library' issue is a red herring.
--grendel drago -
An Entertaining Solution...
You can get a lot more than room temperature monitoring, if you want. I use a Davis Instruments weather station to monitor server room temperature as well as outside temperature, wind speed+direction, humidity, barometer, etc.
I use the Davis Weather Monitor II station, which can be picked up for about $350. Controlling the station from *NIX couldn't be more simple. I use the Device::WxM2 Perl module to pull data from my station. I wrote a small daemon that stores the data in RRDtool data files, as well as Perl Storables (a representation of a Perl data structure stored in a file). Another daemon monitors the current readings from the storables and sends e-mail to my pager if things go awry.
I even wrote an Asterisk AGI that speaks the weather to the caller. Call 1-866-859-7359 for a demo. -
Grey listing..
For anyone using Postfix, I would highly recommend setting it up to work with Postgrey http://isg.ee.ethz.ch/tools/postgrey/.
This reduced the spam at our installation by over 80% overnight, and has so far had no complaints of false positive.
For a detailed explanation of how this works, see here..http://projects.puremagic.com/greylisting/