All valid points. Again, I'm not deriding the legal profession - just pointing out the difference between a technical discipline and a philisophical / sociological discipline.
Actually, the study of the law is the study of how our society chooses (by common, if tacit, agreement) to enforce internal regulations on its constituents.
Therefore, since it is one particular society versus another, it is arbitrary. I don't believe that a bunch of old guys got around one day and wrote up the laws that govern our society, putting forth such sillyness as "One shall not bother a squirrel" (ref www.dumblaws.com) in one shot. I completely understand that any group of laws is a changing set of rules, practices and standards - and *must* be in order to survive.
That being said, the laws of *ANY* society are a product of that group's experiences. The functioning of said laws within that group will be entirely based on its origins. For example, in American culture, it is not only taboo, but *illegal* to have more than one spouse. It is an arbitrary line that has been drawn. If I went to my family lawyer and said, "I wish to marry a second wife" (presuming the first is still around) he would likely laugh or be confused by my legally impossible request. However, in another culture the practice of polygamy is perfectly acceptable and even encouraged. Consulting a lawyer from that culture would yield different results.
Anyway, the whole point is that since the Law is a living entity and adapts to the culture surrounding it, it is not out of line for us armchair lawyers to question things line vertical property lines. In contrast, there are the objective laws of physics governing things such as computers.
Therefore, I can laugh all I want at the lawyer that doesn't know the difference between RAM and a hard drive while telling me how each should work, but he does not have solid ground to laugh at me for questioning the logic of the current crop of laws.
For the record, I don't think my property line needs to, nor should, implicity extend to low orbit. It was merely an example of an arbitrary decision.
While I agree that I know less of the law than, say...a meter maid, and agree with 90% of your statement, I find one fundamental difference in the two fields.
Engineering is a learned, *technical* discipline while the study of the law is absorbing the arbitrary rules set forth by our predecessors.
Asking someone to "install Windows on his RAM" is laughable because it is simple not possible (don't give me ramdisk arguments, either - I doubt windows will work that way). That action is limited by technical barriers.
The fact that my property line should extend to low orbit but does not is an arbitrary desgnation made for politcal, commercial and/or societal reasons. That "fact" can change based on geographic borders, political climits, etc. The study of law is therefore a study of how one particular, arbitrary system functions now and has functioned in the past (precedent).
Again, I agree that there are a number of armchair lawyers that spout on about things they know nothing about (like me;) ) and I think most lawyers are very intelligent. I just think these are very different disciplines at their base.
Actually, oh ye who art misinformed... The contributions of Christians to the rise of Science in the 1500 and 1600's is vastly documented
Only if one ignores the 1,100 years that Christianity practically (and in some cases, actually) banned rational thought and reason...Science and reason were doing just fine with the Greeks and Romans until the "I know better than you" religion gained political favor
I'll have to second that. I picked up a Lifebook P2120 just under a month ago. The thing rocks. 6 hours of battery life with the high cap batt - 12 hours if I swapped out the DVD/CDRW for another batt. Integrated wireless. 5.1 channel digital audio. To top it off, it only weighs 3.4lbs. Makes my 12" ibook look like a big, bloated beast.
Yes, I have, on a friend's old first-gen Sony DVD player. Worked perfectly. Disc was a DVD-R burnt from an Apple SuperDrive (Pioneer drive).
The first-gen sony's actually were more compatible w/ burned media than the second-gen. In a strugle to reduce the price and gain market penetration, they used cheaper laser assemblies.
My second-gen sony will *not* play *any* burned media.
Places like Yahoo will globally distribute their servers.
Services provided by Digital Island, Mirror Image and Akamai will distribute your content to a node as close to the client as possible. We use those services for our images (only static content we have), but Akamai (at least) is pushing a new distributed processing model. You give them a Java WAR file or a.Net app and they'll push the *app* out to the edge. Expensive, but interesting.
Well, this a problem with any cache system. With ours, you adjust the TTL to an acceptable value of "staleness" down to the second.
When optimising any system, relaxing granularity is something that you should look at. Do I really need the latest version of the news story up to this very second - or can I deal with one that's a minute or more old. In our case, the news stories are edited and reviewed before they're published, so it doesn't matter if the story is 1 minute old or 10 days old.
In an emergency, we can forceably expire an element.
There are cases on our site where we can't cache the data - we *need* the live data. Those cases are scrutinized thoroughly before we actually make a live call to the db to see if there's some way to get around it. However, most of our data is cacheable and we have a hit rate of ~80%
Well, we don't actually cache whole pages. The closest we come is our front page, where the entire page is generated, stored as a text file and included except for the header where your login name appears.
If you were to log into our site, your name is displayed on *each* page - how would you cache that whole page effectively?
We cache objects and have the web servers assemble the objects in a page on the fly. So, a news story is an object, a poll box is an object, etc.
One reason for this is different TTLs. Our news stories don't change that often - if ever - once they've been published. A news story TTL may be set to 1 or 2 hours, while our polls are constantly changing and need a much shorter TTL.
Our main goal with this design was to ease our database load. Scaling a database up is *expensive* (Oracle quoted us $250,000 - for the one box) and complex once you start moving to clusters, etc. Scaling the front end is simple - add another server behind the load balancer. We currently have 6 web servers for redundancy and general zippyness, but our load can be handled by 2 or 3 of those.
I'm not sure I understand the question, but I'll take a crack.
The local cache is simply time based. Each element in the cache has it's own expiration time and part of the API allows you to specify a TTL for each element. The element's timestamp is checked against its TTL with every request - if it's expired, the daemon deletes the element and simply reports that it couldn't find the object.
Another reactive behavior of the daemon is that it will call a trim() (which walks through the hashtable and purges any expired objects that simply haven't been requested since they turned "sour") whenever the hashtable grows to a specified max size. There's some additional logic that keeps trim() storms from occuring.
On a proactive side, the daemon itself does some housekeeping. After X seconds (we have it set to about 2 hours) it trim()'s itself.
Combined with a proper connection pool, they can really save your butt.
However, persistent connections may be too much of a burden for an overworked db server. If you're using PHP/MySQL for example, mysql_pconnect may not be the way to go if you have a few front end servers hitting the database. It seems that the PHP connection pooling limit is per process. If you have 100 Apache processes w/ a 10 connection limit per and 10 web servers, that's a max of 10,000 db connections!!!
One idea might be an intermediate "connection broker" on a per server basis. We use something similar to this.
Apache's fork() model is great for stability, but it really hinders interprocess resource sharing. We're mostly Java based here, which allows us to use beans and such. Does mod_perl allow for resource sharing between processes?
is *the* most important word around for dynamic sites.
I've built a site that's able to handle 1-2 million dynamic page views per day. There's not a single static page on the whole site except for the 404 page.
/. doesn't generate these pages on the fly, they're generated by a background process that runs every minute or so and stored as a file. There's no reason to requery the database if you don't have to.
One trick that we currently use is a little daemon that runs on our app servers (custom java app). It's essentially a tcp socket interface to a hashtable with an expiration timestamp. Here's how the site works:
request comes in
front end server takes GET params and queries the local cache daemon to see if those objects are local
if the objects are local - great - slap them together and deliver the page, otherwise
query the database for the object info
populate the cache daemon
deliver the page
Another trick we use is dumping the output from one dynamic page to be included by another. So, have a page that generates nothing but an element (eg. slashbox). Have a mechanism on the back end that requests that page and stores the result as a text file. The dynamic page (say, php or jsp) just uses an include directive pointing to the static text file - which can be formatted html.
Of course, the real weak point of the system (without clustering) is the database. Make sure that your data is index properly and that your queries are optimised. We have 2 tables with over a million rows each that get hit all the time. Proper data layout, quick queries and the local caches help our puny dual P3-733 (NON xeon) with a paltry 1GB of RAM dish out well over a million dynamic pages per day.
You know that metal bar on the back of the trailer? Yeah that's what is supposed to protect you from being decapitated, all trucks have them.
If you had ever worked with large trucks first hand you'd realize that those things are largely worthless.
First, there are loading docks that actually latch onto the underride bars to keep the trailers in place - how many times do you think people forget to disengage them before trying to drive off. This doesn't always tear the guard off, just weakens it.
Second, those guards are often too high to stop a car from underriding. The theory is that they will hit your engine block, collapse and scrape along your hood - buckling it - until you stop. Um, yeah. That works great if you're in something with a hood that high. (hint: Metro and Miata drivers are screwed)
Anyway, I agree with you that there is a higher percentage of safe and conscientious drivers with a CDL than not. The real problem is that 1 bad truck driver can 100x more lethal per incident than some poor schmuck in an Aspire with no clue. Unfortunately, there are too many schmucks on the road creating too many incidents.
Back (sorta) on topic, there definitely needs to be *some* sort of regulation on coasters - operationally as well as mechanically. At the bare minimum, I'd like to see info outside the ride on max speed, max G, sustained G and running time - so I don't wait 2 hours in line for a 10 second ride!;-).
Re:How different is this than MRAM?
on
No More Rebooting?
·
· Score: 3, Informative
Just remember - the uptime counter rolls at ~497 days.:-)
Scared the Hell out of me when I saw my DB server with an uptime of 23 days...until I realized that it had indeed been up for 520 days. This machine gets *hammered*, too.
I'm sorry, would somebody mind explaining this ^H^H^H^H thing to me?
^H is a "delete" character. On some terminals, where the backspace is a different character code, whenever you hit the backspace key ^H shows up instead of actually deleting the last char.
I once found a drive in a client's machine that was so hosed that the head had actually *severed* the platter. I picked up the drive and *rattle*rattle*. Fairly easy to troubleshoot that one.:-)
There are ModChips that will *only* play imports. I'm not sure on how the PS2 has upgraded things, but the PSX/one had two things gumming the works.
1) There was a block with an impossible checksum on the disc. No CD burner (except for the pros') would write such a checksum.
2) There was also a region code placed in there.
When the PSX booted up, it grabbed the checksum and region code to make sure that it was a real disc and playing on the proper hardware for the region. All the ModChips do is constantly feed the hardware that checks these codes with good values (the newer 'stealth' chips stop a few seconds after boot).
So, there *are* chips that *only* send the valid region code and *not* the funky checksum. That will let you play any original PSX disc from any country. It doesn't help with "backups" - legal or otherwise.
Needless to say, these chips don't sell very well. They're often sold by legit importers or people with a strong moral adversity to piracy, but not to imports.
As for the homegrown games, that would require some further logic in the chip.
I didn't have any problem whatsoever taking an hour to install the joy-console drivers and *build* a box to plug my original SNES controllers into via the parallel port. They work like a dream:-)
Slashdot Mirror
All valid points. Again, I'm not deriding the legal profession - just pointing out the difference between a technical discipline and a philisophical / sociological discipline.
Actually, the study of the law is the study of how our society chooses (by common, if tacit, agreement) to enforce internal regulations on its constituents.
Therefore, since it is one particular society versus another, it is arbitrary. I don't believe that a bunch of old guys got around one day and wrote up the laws that govern our society, putting forth such sillyness as "One shall not bother a squirrel" (ref www.dumblaws.com) in one shot. I completely understand that any group of laws is a changing set of rules, practices and standards - and *must* be in order to survive.
That being said, the laws of *ANY* society are a product of that group's experiences. The functioning of said laws within that group will be entirely based on its origins. For example, in American culture, it is not only taboo, but *illegal* to have more than one spouse. It is an arbitrary line that has been drawn. If I went to my family lawyer and said, "I wish to marry a second wife" (presuming the first is still around) he would likely laugh or be confused by my legally impossible request. However, in another culture the practice of polygamy is perfectly acceptable and even encouraged. Consulting a lawyer from that culture would yield different results.
Anyway, the whole point is that since the Law is a living entity and adapts to the culture surrounding it, it is not out of line for us armchair lawyers to question things line vertical property lines. In contrast, there are the objective laws of physics governing things such as computers.
Therefore, I can laugh all I want at the lawyer that doesn't know the difference between RAM and a hard drive while telling me how each should work, but he does not have solid ground to laugh at me for questioning the logic of the current crop of laws.
For the record, I don't think my property line needs to, nor should, implicity extend to low orbit. It was merely an example of an arbitrary decision.
While I agree that I know less of the law than, say...a meter maid, and agree with 90% of your statement, I find one fundamental difference in the two fields.
;) ) and I think most lawyers are very intelligent. I just think these are very different disciplines at their base.
Engineering is a learned, *technical* discipline while the study of the law is absorbing the arbitrary rules set forth by our predecessors.
Asking someone to "install Windows on his RAM" is laughable because it is simple not possible (don't give me ramdisk arguments, either - I doubt windows will work that way). That action is limited by technical barriers.
The fact that my property line should extend to low orbit but does not is an arbitrary desgnation made for politcal, commercial and/or societal reasons. That "fact" can change based on geographic borders, political climits, etc. The study of law is therefore a study of how one particular, arbitrary system functions now and has functioned in the past (precedent).
Again, I agree that there are a number of armchair lawyers that spout on about things they know nothing about (like me
Actually, oh ye who art misinformed... The contributions of Christians to the rise of Science in the 1500 and 1600's is vastly documented Only if one ignores the 1,100 years that Christianity practically (and in some cases, actually) banned rational thought and reason...Science and reason were doing just fine with the Greeks and Romans until the "I know better than you" religion gained political favor
no /etc/inittab there to bork your completion, eh? where does init pull its config on your box???
Yes, I do use a Linux-based desktop system, with no VMware crud
Blashpemer!! VMware is not crud! VMware is one of the greatest programs I have ever used!
You may not have need for it but that doesn't make it crud...
back on topic; as for the lack of egress filtering, you could always run SP2 inside a virtual machine and use iptables...overkill? what overkill?
I'm off to ask google "What is the answer to life, the universe, and everything?"
Go right ahead. Google throws its built-in calculator at the question and comes up with...42!!
I have linux on it, but I've been working on too many other projects to play with acpi, yet.
I'll have to second that. I picked up a Lifebook P2120 just under a month ago. The thing rocks. 6 hours of battery life with the high cap batt - 12 hours if I swapped out the DVD/CDRW for another batt. Integrated wireless. 5.1 channel digital audio. To top it off, it only weighs 3.4lbs. Makes my 12" ibook look like a big, bloated beast.
Properly designed hardware should not do this. Tell that to Apple - My iBook has done this since day one.
Yes, I have, on a friend's old first-gen Sony DVD player. Worked perfectly. Disc was a DVD-R burnt from an Apple SuperDrive (Pioneer drive).
The first-gen sony's actually were more compatible w/ burned media than the second-gen. In a strugle to reduce the price and gain market penetration, they used cheaper laser assemblies.
My second-gen sony will *not* play *any* burned media.
mod parent up - great link!
Places like Yahoo will globally distribute their servers.
.Net app and they'll push the *app* out to the edge. Expensive, but interesting.
Services provided by Digital Island, Mirror Image and Akamai will distribute your content to a node as close to the client as possible. We use those services for our images (only static content we have), but Akamai (at least) is pushing a new distributed processing model. You give them a Java WAR file or a
Well, this a problem with any cache system. With ours, you adjust the TTL to an acceptable value of "staleness" down to the second.
When optimising any system, relaxing granularity is something that you should look at. Do I really need the latest version of the news story up to this very second - or can I deal with one that's a minute or more old. In our case, the news stories are edited and reviewed before they're published, so it doesn't matter if the story is 1 minute old or 10 days old.
In an emergency, we can forceably expire an element.
There are cases on our site where we can't cache the data - we *need* the live data. Those cases are scrutinized thoroughly before we actually make a live call to the db to see if there's some way to get around it. However, most of our data is cacheable and we have a hit rate of ~80%
Well, we don't actually cache whole pages. The closest we come is our front page, where the entire page is generated, stored as a text file and included except for the header where your login name appears.
If you were to log into our site, your name is displayed on *each* page - how would you cache that whole page effectively?
We cache objects and have the web servers assemble the objects in a page on the fly. So, a news story is an object, a poll box is an object, etc.
One reason for this is different TTLs. Our news stories don't change that often - if ever - once they've been published. A news story TTL may be set to 1 or 2 hours, while our polls are constantly changing and need a much shorter TTL.
Our main goal with this design was to ease our database load. Scaling a database up is *expensive* (Oracle quoted us $250,000 - for the one box) and complex once you start moving to clusters, etc. Scaling the front end is simple - add another server behind the load balancer. We currently have 6 web servers for redundancy and general zippyness, but our load can be handled by 2 or 3 of those.
I'm not sure I understand the question, but I'll take a crack.
The local cache is simply time based. Each element in the cache has it's own expiration time and part of the API allows you to specify a TTL for each element. The element's timestamp is checked against its TTL with every request - if it's expired, the daemon deletes the element and simply reports that it couldn't find the object.
Another reactive behavior of the daemon is that it will call a trim() (which walks through the hashtable and purges any expired objects that simply haven't been requested since they turned "sour") whenever the hashtable grows to a specified max size. There's some additional logic that keeps trim() storms from occuring.
On a proactive side, the daemon itself does some housekeeping. After X seconds (we have it set to about 2 hours) it trim()'s itself.
Combined with a proper connection pool, they can really save your butt.
However, persistent connections may be too much of a burden for an overworked db server. If you're using PHP/MySQL for example, mysql_pconnect may not be the way to go if you have a few front end servers hitting the database. It seems that the PHP connection pooling limit is per process. If you have 100 Apache processes w/ a 10 connection limit per and 10 web servers, that's a max of 10,000 db connections!!!
One idea might be an intermediate "connection broker" on a per server basis. We use something similar to this.
Apache's fork() model is great for stability, but it really hinders interprocess resource sharing. We're mostly Java based here, which allows us to use beans and such. Does mod_perl allow for resource sharing between processes?
I've built a site that's able to handle 1-2 million dynamic page views per day. There's not a single static page on the whole site except for the 404 page.
One trick that we currently use is a little daemon that runs on our app servers (custom java app). It's essentially a tcp socket interface to a hashtable with an expiration timestamp. Here's how the site works:
- request comes in
- front end server takes GET params and queries the local cache daemon to see if those objects are local
- if the objects are local - great - slap them together and deliver the page, otherwise
- query the database for the object info
- populate the cache daemon
- deliver the page
Another trick we use is dumping the output from one dynamic page to be included by another. So, have a page that generates nothing but an element (eg. slashbox). Have a mechanism on the back end that requests that page and stores the result as a text file. The dynamic page (say, php or jsp) just uses an include directive pointing to the static text file - which can be formatted html.Of course, the real weak point of the system (without clustering) is the database. Make sure that your data is index properly and that your queries are optimised. We have 2 tables with over a million rows each that get hit all the time. Proper data layout, quick queries and the local caches help our puny dual P3-733 (NON xeon) with a paltry 1GB of RAM dish out well over a million dynamic pages per day.
The proportion of highly fanatical Mac users doesn't say anything to you?
One word: Scientology.
You know that metal bar on the back of the trailer? Yeah that's what is supposed to protect you from being decapitated, all trucks have them.
;-).
If you had ever worked with large trucks first hand you'd realize that those things are largely worthless.
First, there are loading docks that actually latch onto the underride bars to keep the trailers in place - how many times do you think people forget to disengage them before trying to drive off. This doesn't always tear the guard off, just weakens it.
Second, those guards are often too high to stop a car from underriding. The theory is that they will hit your engine block, collapse and scrape along your hood - buckling it - until you stop. Um, yeah. That works great if you're in something with a hood that high. (hint: Metro and Miata drivers are screwed)
Anyway, I agree with you that there is a higher percentage of safe and conscientious drivers with a CDL than not. The real problem is that 1 bad truck driver can 100x more lethal per incident than some poor schmuck in an Aspire with no clue. Unfortunately, there are too many schmucks on the road creating too many incidents.
Back (sorta) on topic, there definitely needs to be *some* sort of regulation on coasters - operationally as well as mechanically. At the bare minimum, I'd like to see info outside the ride on max speed, max G, sustained G and running time - so I don't wait 2 hours in line for a 10 second ride!
Just remember - the uptime counter rolls at ~497 days. :-)
Scared the Hell out of me when I saw my DB server with an uptime of 23 days...until I realized that it had indeed been up for 520 days. This machine gets *hammered*, too.
I'm sorry, would somebody mind explaining this ^H^H^H^H thing to me? ^H is a "delete" character. On some terminals, where the backspace is a different character code, whenever you hit the backspace key ^H shows up instead of actually deleting the last char.
Doggie Style is also a beer from the Flying Dog litter :-)
I've got ya one worse (but no picture :-( )
:-)
I once found a drive in a client's machine that was so hosed that the head had actually *severed* the platter. I picked up the drive and *rattle*rattle*. Fairly easy to troubleshoot that one.
There are ModChips that will *only* play imports. I'm not sure on how the PS2 has upgraded things, but the PSX/one had two things gumming the works.
1) There was a block with an impossible checksum on the disc. No CD burner (except for the pros') would write such a checksum.
2) There was also a region code placed in there.
When the PSX booted up, it grabbed the checksum and region code to make sure that it was a real disc and playing on the proper hardware for the region. All the ModChips do is constantly feed the hardware that checks these codes with good values (the newer 'stealth' chips stop a few seconds after boot).
So, there *are* chips that *only* send the valid region code and *not* the funky checksum. That will let you play any original PSX disc from any country. It doesn't help with "backups" - legal or otherwise.
Needless to say, these chips don't sell very well. They're often sold by legit importers or people with a strong moral adversity to piracy, but not to imports.
As for the homegrown games, that would require some further logic in the chip.
What kind of joystick?
:-)
I didn't have any problem whatsoever taking an hour to install the joy-console drivers and *build* a box to plug my original SNES controllers into via the parallel port. They work like a dream