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>> I would have thought that needing more disk space is such a crushingly
>> rare event that it makes almost no sense to optimise for it.
>
> No it's not. You may need to run an app in debug mode for a while and
> need extra space to store the dumps. You may run into seasonal peeks and
> need extra storage just for that period. Etc... Sizing hundreds of
> servers for a worst case scenario is not efficient use of the company's
> money. You are much better off having some amount of slack space that
> you can swing around when needed.
Maybe that's the problem. I cannot imagine any task that would ever
require "hundreds of servers". I'm struggling to think of a task that
would require more than about a dozen at worst. I mean, unless you work
for one of the largest companies on the planet, which almost nobody does.
>> If you have
>> to take a server offline once every 5 years to add another disk, that's
>> still 99.99% uptime.
>
> Not if your contract says "monthly uptime of 99.99%". ;-)
Mmm, good point.
>> You claimed that it's not insane to run a SAN over the Internet,
>
> When did I say that?
Francois Labreque wrote:
> We've also had the performance discussion before. Yes, the
> theoretical access speed of a local SATA drive is much faster than
> that of a SAN attached logical disk, but in actual real world
> practice, with real world data, there's not much of a difference,
> even on SANs located halfway across town in another building.
>>> most SAN implementations run dedicated protocols over
>>> fibre at Gbps speeds.
>>
>> It's news to me that such things even exist yet - but perhaps that was
>> your point?
>
> Actually, it shouldn't be news to you. We went over this in great
> details a few months ago. Remember my nice ascii-graphics chart with the
> servers, SAN switches, drive enclosures and tape units?
I don't remember much of the detail of that discussion - in particular,
I don't recall there being any actual speed numbers involved. But still,
as I say, it looks like I will get to see for myself shortly.
> Not that SANs are infaillible, but why do you assume that it will fail?
They want to back up 200GB of data per day over a 5 Mbit/sec Internet
connection. You do the math.
Plus, since when does rolling out a brand new complex system go
smoothly? ;-)
>> So what you're saying is that a handful of the richest companies on
>> Earth can afford to do this?
>
> There's more than a handful of companies who can afford it. A few £M in
> extra telco costs per year is nothing compared to the prospect of going
> out of business because your data centre had a 110-story building crash
> on top of it.
So you're saying that more than "a handful" of telco companies exist?
>> Yeah, I guess that'll be why I haven't seen it before. :-P
>
> I have never seen the Merryll-Lynch data centre first hand, either, but
> that isn't necessary to know that they were back up and running hours
> after the WTC towers fell... Reading the story of how they restarted
> their operations from their disaster recovery location was enough. Then
> the "Interesting...how'd they manage that?" questions popped up in my
> head, and I started digging...
My first question would have been "who is Merryll-Lynch?", but OK.
> Which is the main point of this whole discussion: reading the newspaper
> and other news-related web sites, once in a while, is not a bad thing,
> even if the event in question doesn't affect you directly, there may be
> bits of insight to be gathered.
Hmm. I'm now trying to remember how the hell we *got* to this topic in
the first place... (Just look at that subject line!)
At any rate, I agree there certainly isn't anything /bad/ about reading
news-related stuff. I just don't see how it is an absolutely mandatory
requirement of being alive, that's all.
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Le 2012-02-02 05:24, Invisible a écrit :
>
> I can see that knowing about how (say) Google manages their data centres
> might be quite useful if you're applying to Google. If you're applying
> to somebody who isn't Google, I'm not sure how that's useful.
>
IT manager: "We have multiple data centres, built out of containers,
each with their own blah blah blah..."
Darren: "Ah.. Like Google?"
IT Manager (to himself) "Good. I won't have to go over it with this
candidate." (to Darren) "Yes, except that they do XYZ, whereas we rely
on ABC to do that... Yada Yada Yada...
-----
IT manager: "We have multiple data centres, built out of containers,
each with their own blah blah blah..."
Andy: "I didn't know you could do that!"
IT Manager (to himself) "Sigh. I'm going to have to start from the
birds and Bees with this guy..."
-----
Which of the two, do you think the IT manager will hire?
> ...unless it *isn't* useful at all, it's just another one of those
> worthless things that "create the right impression".
>
>>> As usual with Wikipedia, the page babbles about updates and feeds and
>>> XML and "syndication" and something about RDF, but utterly fails to
>>> explain WHAT IT IS.
>>
>> <sigh>
>>
>> From wikipedia:
>>
>> --- snip ---
>>
>> RSS feeds benefit publishers by letting them syndicate content
>> automatically.
>
> WTF does "syndicate" mean?
>
>> A standardized XML file format allows the information to
>> be published once and viewed by many different programs.
>
> Because XHTML isn't an XML format already. Oh, wait... actually yes it
> is. And many different programs can view it. So...?
>
>> They benefit
>> readers who want to subscribe to timely updates from favorite websites or
>> to aggregate feeds from many sites into one place.
>
> This at least hints at what RSS is actually about. But it still seems
> quite vague. I'm still not clear exactly what it's getting at.
>
>> RSS feeds can be read using software called an "RSS reader", "feed
>> reader", or "aggregator", which can be web-based, desktop-based, or
>> mobile-device-based.
>
> So... you need software that supports RSS in order to use RSS? OK, fair
> enough.
>
>> The user subscribes to a feed by entering into the
>> reader the feed's URI or by clicking a feed icon in a web browser that
>> initiates the subscription process.
>
> We still haven't established exactly what point "subscribing" serves,
> but OK...
>
>> The RSS reader checks the user's
>> subscribed feeds regularly for new work, downloads any updates that it
>> finds, and provides a user interface to monitor and read the feeds.
>
> This is all very abstract. It checks "regularly" for "new work",
> downloads any "updates", and provides a UI to "monitor" such updates. So
> what does that *mean*, in real world terms?
>
>> RSS
>> allows users to avoid manually inspecting all of the websites they are
>> interested in, and instead subscribe to websites such that all new
>> content is pushed onto their browsers when it becomes available.
>
> As best as I can tell, the idea behind RSS seems to be that you can see
> if any of your subscribed websites have been updated, without having to
> visit each of them one at a time. (As if that's in some way "hard" or
> something.) Why the heck the article doesn't just /say/ this on line
> one, I don't know. Instead it talks obliquely about how "all new content
> is pushed onto the browser when it becomes available". (Funny, when it
> says a feed reader "regularly checks for updates", that sounds to me
> like a /pull/ model, not /push/...)
>
>> Now, I read your blog and keep up on it by using - that's right - an RSS
>> feed.
>
> Damn... and I thought I'd turned that off... heh. Apparently not.
>
>> I have the feed set up in Google Reader so that when you post
>> something new on your blog, I see it as part of the Reader page.
>>
>> That way I don't have to visit your blog to see what's going on in your
>> blog. I see an item show up in my reading list so, as wikipedia says, I
>> "avoid manually inspecting all of the websites [I] am interested in" and
>> can see what's new.
>
> So what does that actually look like? I'm still trying to get my head
> around how this actually works. What counts as "new content", how it
> displays all this stuff in an intelligible form, and so on.
>
>>>>> I usually visit Tom's Hardware when I want to see what's happening in
>>>>> the hardware world.
>>>>
>>>> I doubt you're going to get that by reading some text on a screen.
>>>
>>> That's why I just built a new PC - to experience the Core i7 first-hand.
>>> :-P
>>
>> So then why bother going to Tom's Hardware again?
>
> Sarcasm? :-P
>
>>> The BBC's iPlayer system "works". I mean, it's so horrifyingly blurry
>>> that you sometimes can't see people's faces clearly enough to recognise
>>> who's who, and often the end credits are unreadable. But technically
>>> that still counts as "works", right?
>>
>> I don't know what kind of connection you use, but I stream on iPlayer
>> occasionally from halfway around the world (did that with last night of
>> the proms IIRC) and projected it onto a 10' screen. Didn't look
>> particularly blurry to me.
>
> Want to bet that the BBC has servers all over the world?
>
> With the latest update to our set top box, we can actually access
> iPlayer and display it on a real TV. I can actually compare the recorded
> TV broadcast directly next to the iPlayer version of the exact same
> program. And let me tell you, the image quality is incomparable. (And
> that's only SD, not HD.)
>
> On top of that, at peak times iPlayer becomes almost unusable. It
> freezes constantly. I'm not sure whether it's the BBC servers or the ISP
> network that can't keep up, but you just can't watch anything. But then,
> if you select "high quality mode", then it runs like that all the time.
>
> I don't think an 8 Mbit/sec Internet connection would be considered
> especially slow...
>
>>> I just looked it up. The transfer rate of a DVD is 10.5 mbit/sec. The
>>> maximum broadband speed you can get is 8 mbit/sec. So... does that mean
>>> that people in America have something faster than ADSL or something?
>>
>> I don't - I have 3 Mbps down ADSL. I have to not be doing other things
>> with the network connection when I'm streaming Netflix, but I do get a
>> high quality HD image with 5.1 sound with programmes that include it.
>
> The sound isn't the problem, it's the video. Sound is easily streamable.
> But I'm baffled as to how you can download video in anything approaching
> real-time, unless the quality is diabolically poor.
>
>> But more to the point, do you now understand what streaming is?
>
> Yes. Although I'm still puzzled as to how anybody could make money out
> of selling such poor quality stuff...
--
/*Francois Labreque*/#local a=x+y;#local b=x+a;#local c=a+b;#macro P(F//
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Le 2012-02-02 05:26, Invisible a écrit :
>>> I would have thought that needing more disk space is such a crushingly
>>> rare event that it makes almost no sense to optimise for it.
>>
>> No it's not. You may need to run an app in debug mode for a while and
>> need extra space to store the dumps. You may run into seasonal peeks and
>> need extra storage just for that period. Etc... Sizing hundreds of
>> servers for a worst case scenario is not efficient use of the company's
>> money. You are much better off having some amount of slack space that
>> you can swing around when needed.
>
> Maybe that's the problem. I cannot imagine any task that would ever
> require "hundreds of servers". I'm struggling to think of a task that
> would require more than about a dozen at worst. I mean, unless you work
> for one of the largest companies on the planet, which almost nobody does.
>
While it's true that most tasks performed by the Fortune 1000 rarely
take more than a dozen or so servers. Each of those companies have
dozens of such tasks.
For example:
- A bank of web servers for their corporate web site
- A handfull of DNSes
- A couple entreprise directory servers, authentication servers, etc...
- 1 mail server per 1000 employee
- 1 file server per 1000 employee
- A dozen servers for the HR apps
- A dozen servers for the Finance/accounting dept.
- A couple dedicated server for the law dept. (Confidentiality)
- Server monitoring servers.
- Network monitoring servers.
- Environment monitoring servers (Heating/air conditioning, power
consumption, generators, battery banks, etc...)
- and then... more servers for the actual business that company does, be
it putting people on planes, managing people's money, building cars, or
selling drugs.
Split those across a few data centres for geographical proximity to the
user base and duplicate all the mission-critical servers.
Tada!
I don't understand why you somehow think one needs to actually work for
British Airways, Siemens, Yamaha or IBM to be able to imagine what's
it's like to work in a company with 100,000+ employees.
>>> You claimed that it's not insane to run a SAN over the Internet,
>>
>> When did I say that?
>
> Francois Labreque wrote:
> > We've also had the performance discussion before. Yes, the
> > theoretical access speed of a local SATA drive is much faster than
> > that of a SAN attached logical disk, but in actual real world
> > practice, with real world data, there's not much of a difference,
> > even on SANs located halfway across town in another building.
>
"In another building" DOES NOT mean "over the Internet". Private data
circuits predate the internet, and no company would use the Internet to
link two data centres together. Remote offices, maybe, but definitely
not data centres. 15 years ago, it would have been done via data-grade
telco circuits (such as an E1 or E3 line, usually called a WAN circuit).
Nowadays, it's done via DWDM optical circuits (usually called a MAN or
Metronet).
>> Not that SANs are infaillible, but why do you assume that it will fail?
>
> They want to back up 200GB of data per day over a 5 Mbit/sec Internet
> connection. You do the math.
So their backup strategy will fail. Not the actual SAN. Gotcha.
>
> Plus, since when does rolling out a brand new complex system go
> smoothly? ;-)
>
When it's planned properly. I've seen it happen. But, I must admit,
that I've seen quite a few disasters, too.
>>> So what you're saying is that a handful of the richest companies on
>>> Earth can afford to do this?
>>
>> There's more than a handful of companies who can afford it. A few £M in
>> extra telco costs per year is nothing compared to the prospect of going
>> out of business because your data centre had a 110-story building crash
>> on top of it.
>
> So you're saying that more than "a handful" of telco companies exist?
>
There are, in fact, more than a handful of telcos in most countries.
while the actual wires underground usually belong to one or two
companies, the other ones will buy bandwidth from the
cable-owning-entity and resell it to other corporations. This is why,
for example, I can rent circuits from BT in Canada, even though they do
not own any of the fibre optics here.
But this has nothing to do with the fact that I was talking about
businesses buying telecommunications services from the telcos, not the
telcos themselves. Last time I checked HSBC was not a telco, and I do
know that they've had 10Gbps links between their data centres for over
10 years.
--
/*Francois Labreque*/#local a=x+y;#local b=x+a;#local c=a+b;#macro P(F//
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> I don't understand why you somehow think one needs to actually work for
> British Airways, Siemens, Yamaha or IBM to be able to imagine what's
> it's like to work in a company with 100,000+ employees.
It's like the thing with Google's data centre. A "computer" is a
low-power device. Unless you've ever worked with thousands of them at
once, it just doesn't occur to you what there might be power supply or
cooling issues to overcome.
I imagine the reverse also applies; somebody who works for Google would
probably think that the solution to "our tape drive just died" is "so go
buy a new one". They probably wouldn't even realise that to a small
company, £3,000 for a new tape drive is actually /a crapload of money/.
It probably wouldn't even occur to them.
In short, you don't really understand what it's like to work within a
given set of constraints unless, you know, you've had to work within
that set of constraints...
>> Francois Labreque wrote:
>> > We've also had the performance discussion before. Yes, the
>> > theoretical access speed of a local SATA drive is much faster than
>> > that of a SAN attached logical disk, but in actual real world
>> > practice, with real world data, there's not much of a difference,
>> > even on SANs located halfway across town in another building.
>
> "In another building" DOES NOT mean "over the Internet". Private data
> circuits predate the internet, and no company would use the Internet to
> link two data centres together.
How is that even *possible*? It's not like you can just go to the
hardware store and buy 25km of copper wire and then put it into the
ground with a shovel on your day off or something...
>>> Not that SANs are infaillible, but why do you assume that it will fail?
>>
>> They want to back up 200GB of data per day over a 5 Mbit/sec Internet
>> connection. You do the math.
>
> So their backup strategy will fail. Not the actual SAN. Gotcha.
Well, given that backup is what this SAN is *for*, I guess I mixed up
the two things.
>> Plus, since when does rolling out a brand new complex system go
>> smoothly? ;-)
>
> When it's planned properly. I've seen it happen. But, I must admit, that
> I've seen quite a few disasters, too.
Given the company that *I* work for, would you expect a smooth rollout? ;-)
>> So you're saying that more than "a handful" of telco companies exist?
>
> There are, in fact, more than a handful of telcos in most countries.
> while the actual wires underground usually belong to one or two
> companies, the other ones will buy bandwidth from the
> cable-owning-entity and resell it to other corporations. This is why,
> for example, I can rent circuits from BT in Canada, even though they do
> not own any of the fibre optics here.
>
> But this has nothing to do with the fact that I was talking about
> businesses buying telecommunications services from the telcos, not the
> telcos themselves. Last time I checked HSBC was not a telco, and I do
> know that they've had 10Gbps links between their data centres for over
> 10 years.
OK, so a major /bank/ can also accord crazy technology. None of this
alters the fact that the next tiny company I end up working for won't be
able to afford this kind of thing.
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Le 2012-02-02 10:05, Invisible a écrit :
>> I don't understand why you somehow think one needs to actually work for
>> British Airways, Siemens, Yamaha or IBM to be able to imagine what's
>> it's like to work in a company with 100,000+ employees.
>
> It's like the thing with Google's data centre. A "computer" is a
> low-power device. Unless you've ever worked with thousands of them at
> once, it just doesn't occur to you what there might be power supply or
> cooling issues to overcome.
>
> I imagine the reverse also applies; somebody who works for Google would
> probably think that the solution to "our tape drive just died" is "so go
> buy a new one". They probably wouldn't even realise that to a small
> company, £3,000 for a new tape drive is actually /a crapload of money/.
> It probably wouldn't even occur to them.
>
> In short, you don't really understand what it's like to work within a
> given set of constraints unless, you know, you've had to work within
> that set of constraints...
>
Agreed. When I have a $250,000* piece of equipment that fails, I call
the toll-free number of the hardware vendor and they send me a
replacement in less than 24 hours, meanwhile its redundant mate keeps
the network running. I don't have to deal with purchasing, maintenance
contracts or any of that.
BUT - and that's the important part - I thanks the FSM every chance I
get to not have to deal with these issues. I've read too many horror
stories in comp.dcom.sys.cisco of people who had mission-critical
hardware fail and were asking for help trying to get the device back up
while trying to convince management to buy a new one, or looking for
spare parts on eBay.
*I assume that's how much these things cost as I have absolutely never
had to use the $ key on my keyboard, unless I was programming in Perl.
>>> Francois Labreque wrote:
>>> > We've also had the performance discussion before. Yes, the
>>> > theoretical access speed of a local SATA drive is much faster than
>>> > that of a SAN attached logical disk, but in actual real world
>>> > practice, with real world data, there's not much of a difference,
>>> > even on SANs located halfway across town in another building.
>>
>> "In another building" DOES NOT mean "over the Internet". Private data
>> circuits predate the internet, and no company would use the Internet to
>> link two data centres together.
>
> How is that even *possible*? It's not like you can just go to the
> hardware store and buy 25km of copper wire and then put it into the
> ground with a shovel on your day off or something...
>
You don't do it yourself, unless you are in a campus environment and can
easily rip up the parking lot and lay down your own fibre or copper.
Step 1. Call your telco rep and order a circuit between site A and site A.
Step 2. Telco will forward the request to a planner who will determine
if the existing cabling between both sites and central offices (CO) has
enough available bandwidth.
Step 3a. If not, the planner will forward the request to their
infrastructure group who will get diging permits from the
city/county/whatever and lay down new bundles of cables.
Step 3b. If the answer is yes, or once the new cables have been laid,
the telco planner will forward your request to an enabler who will
configure the CO switches to map the circuit from Site A's demarcation
point to Site B's demarcation point.
Step 4. Technicians will come on site, at both locations, and terminate
the circuit from their demarc point to the exact rack you ask them to.
Step 5. You plug in the circuit in your equipment (router, switch, or
mainframe front-end-processor, to name a few)
Tada!
Usually, all of this is done for a small nominal fee. Any work they
have to do between demarc points will be undertaken at their own
expense, which they will recoup on your monthly usage bill, of course.
By the way, if you ordered an "internet" link, the exact same steps
would have to take place, except that they would be duplicated for site
A to ISP and ISP to site B, and then the ISP would add its own routers
at both ends and charge you twice as much and more for the "managed
services".
>>>> Not that SANs are infaillible, but why do you assume that it will fail?
>>>
>>> They want to back up 200GB of data per day over a 5 Mbit/sec Internet
>>> connection. You do the math.
>>
>> So their backup strategy will fail. Not the actual SAN. Gotcha.
>
> Well, given that backup is what this SAN is *for*, I guess I mixed up
> the two things.
>
I thought the SAN would replace some of the servers' internal disks. Sorry.
>>> Plus, since when does rolling out a brand new complex system go
>>> smoothly? ;-)
>>
>> When it's planned properly. I've seen it happen. But, I must admit, that
>> I've seen quite a few disasters, too.
>
> Given the company that *I* work for, would you expect a smooth rollout? ;-)
>
>>> So you're saying that more than "a handful" of telco companies exist?
>>
>> There are, in fact, more than a handful of telcos in most countries.
>> while the actual wires underground usually belong to one or two
>> companies, the other ones will buy bandwidth from the
>> cable-owning-entity and resell it to other corporations. This is why,
>> for example, I can rent circuits from BT in Canada, even though they do
>> not own any of the fibre optics here.
>>
>> But this has nothing to do with the fact that I was talking about
>> businesses buying telecommunications services from the telcos, not the
>> telcos themselves. Last time I checked HSBC was not a telco, and I do
>> know that they've had 10Gbps links between their data centres for over
>> 10 years.
>
> OK, so a major /bank/ can also accord crazy technology. None of this
> alters the fact that the next tiny company I end up working for won't be
> able to afford this kind of thing.
What makes you think you can't find work in a large company?
--
/*Francois Labreque*/#local a=x+y;#local b=x+a;#local c=a+b;#macro P(F//
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/* gmail.com */}camera{orthographic location<6,1.25,-6>look_at a }
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On Thu, 02 Feb 2012 10:05:04 +0000, Invisible wrote:
> On 02/02/2012 02:50 AM, Darren New wrote:
>> On 1/31/2012 1:12, Invisible wrote:
>>> As usual with Wikipedia, the page babbles about updates and feeds and
>>> XML and "syndication" and something about RDF, but utterly fails to
>>> explain WHAT IT IS.
>>
>> I have to ask... Do you start reading at the beginning of the article,
>> or do you skip over the part that comes before the table of contents or
>> something?
>>
>> First sentence in the article:
>>
>> "RSS ... is a family of ... formats used to publish frequently updated
>> works ... in a standardized format."
>>
>> How is that not telling you what it is?
>
> HTML is "a family of formats used to publish works [frequently updated
> or not] in a standardized format". As is PDF. As is PostScript. How is
> RSS different?
>
> Sometimes the dictionary definition of what something is turns out not
> to be very enlightening. For example, you could say that
>
> "A knife is a device constructed from a hard material, usually in the
> shape of a triangular prism who's cross-section has a very acute angle
> between two of the sides."
>
> Or you could say "a knife is a device for cutting things". The latter is
> infinitely more illuminating.
You're being fairly obtuse here, Andy.
Go have a look at reader.google.com. There's a tour on the site that
shows you how RSS feeds are useful.
Jim
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On Thu, 02 Feb 2012 10:24:48 +0000, Invisible wrote:
>> But if you're unaware of what Citrix even *does*, then that calls into
>> question (in an interview) whether you even know what's going on in IT.
>
> I can see that knowing about how (say) Google manages their data centres
> might be quite useful if you're applying to Google. If you're applying
> to somebody who isn't Google, I'm not sure how that's useful.
>
> ...unless it *isn't* useful at all, it's just another one of those
> worthless things that "create the right impression".
Being aware of technology is important.
You find yourself in a job that you'd like to get out of, but you have no
idea how to do it.
People give you ideas, and you assert "that can't possibly work" or "that
can't possibly be useful".
But people who do those things actually find other jobs.
You don't do those things, and you don't have luck finding another job.
What does this tell you?
>>> As usual with Wikipedia, the page babbles about updates and feeds and
>>> XML and "syndication" and something about RDF, but utterly fails to
>>> explain WHAT IT IS.
>>
>> <sigh>
>>
>> From wikipedia:
>>
>> --- snip ---
>>
>> RSS feeds benefit publishers by letting them syndicate content
>> automatically.
>
> WTF does "syndicate" mean?
http://dictionary.reference.com/browse/syndicate
Definition 8.
>> A standardized XML file format allows the information to be published
>> once and viewed by many different programs.
>
> Because XHTML isn't an XML format already. Oh, wait... actually yes it
> is. And many different programs can view it. So...?
Again, go look a the tour of Google Reader.
>> They benefit readers who want to subscribe to timely updates from
>> favorite websites or to aggregate feeds from many sites into one place.
>
> This at least hints at what RSS is actually about. But it still seems
> quite vague. I'm still not clear exactly what it's getting at.
Look at the tour.
>> RSS feeds can be read using software called an "RSS reader", "feed
>> reader", or "aggregator", which can be web-based, desktop-based, or
>> mobile-device-based.
>
> So... you need software that supports RSS in order to use RSS? OK, fair
> enough.
Yes, now you're understanding it. Software or - surprise - another
website.
>> The user subscribes to a feed by entering into the reader the feed's
>> URI or by clicking a feed icon in a web browser that initiates the
>> subscription process.
>
> We still haven't established exactly what point "subscribing" serves,
> but OK...
Yes, actually, we have. Subscribing means that instead of going to
Orphi's blog to see what he's written recently, I can go to my reader and
see what he's written recently. Along with a bunch of other sources all
at once.
>> The RSS reader checks the user's subscribed feeds regularly for new
>> work, downloads any updates that it finds, and provides a user
>> interface to monitor and read the feeds.
>
> This is all very abstract. It checks "regularly" for "new work",
> downloads any "updates", and provides a UI to "monitor" such updates. So
> what does that *mean*, in real world terms?
It means I can see that you've written something new in your blog without
going and visiting your blog.
And about 100 other sites that I keep an eye on without visiting them
each every day to see what's new.
>> RSS allows users to avoid manually inspecting all of the websites they
>> are interested in, and instead subscribe to websites such that all new
>> content is pushed onto their browsers when it becomes available.
>
> As best as I can tell, the idea behind RSS seems to be that you can see
> if any of your subscribed websites have been updated, without having to
> visit each of them one at a time. (As if that's in some way "hard" or
> something.) Why the heck the article doesn't just /say/ this on line
> one, I don't know. Instead it talks obliquely about how "all new content
> is pushed onto the browser when it becomes available". (Funny, when it
> says a feed reader "regularly checks for updates", that sounds to me
> like a /pull/ model, not /push/...)
It's time consuming to visit 100 sites to see if there's anything new.
It's far easier to be alerted when there's something new that might be of
interest.
>> I have the feed set up in Google Reader so that when you post something
>> new on your blog, I see it as part of the Reader page.
>>
>> That way I don't have to visit your blog to see what's going on in your
>> blog. I see an item show up in my reading list so, as wikipedia says,
>> I "avoid manually inspecting all of the websites [I] am interested in"
>> and can see what's new.
>
> So what does that actually look like? I'm still trying to get my head
> around how this actually works. What counts as "new content", how it
> displays all this stuff in an intelligible form, and so on.
Look at the Google Reader tour.
>>>>> I usually visit Tom's Hardware when I want to see what's happening
>>>>> in the hardware world.
>>>>
>>>> I doubt you're going to get that by reading some text on a screen.
>>>
>>> That's why I just built a new PC - to experience the Core i7
>>> first-hand.
>>> :-P
>>
>> So then why bother going to Tom's Hardware again?
>
> Sarcasm? :-P
Or perhaps to find out what the latest processor is that you might be
able to afford?
>>> The BBC's iPlayer system "works". I mean, it's so horrifyingly blurry
>>> that you sometimes can't see people's faces clearly enough to
>>> recognise who's who, and often the end credits are unreadable. But
>>> technically that still counts as "works", right?
>>
>> I don't know what kind of connection you use, but I stream on iPlayer
>> occasionally from halfway around the world (did that with last night of
>> the proms IIRC) and projected it onto a 10' screen. Didn't look
>> particularly blurry to me.
>
> Want to bet that the BBC has servers all over the world?
So you just happened to get a crappy connection, while I got a good one?
> With the latest update to our set top box, we can actually access
> iPlayer and display it on a real TV. I can actually compare the recorded
> TV broadcast directly next to the iPlayer version of the exact same
> program. And let me tell you, the image quality is incomparable. (And
> that's only SD, not HD.)
Then your eyes are better than mine, or you got a really crappy
connection.
> On top of that, at peak times iPlayer becomes almost unusable. It
> freezes constantly. I'm not sure whether it's the BBC servers or the ISP
> network that can't keep up, but you just can't watch anything. But then,
> if you select "high quality mode", then it runs like that all the time.
>
> I don't think an 8 Mbit/sec Internet connection would be considered
> especially slow...
And yet I apparently get a better picture at half the speed from the
other side of the planet....
>>> I just looked it up. The transfer rate of a DVD is 10.5 mbit/sec. The
>>> maximum broadband speed you can get is 8 mbit/sec. So... does that
>>> mean that people in America have something faster than ADSL or
>>> something?
>>
>> I don't - I have 3 Mbps down ADSL. I have to not be doing other things
>> with the network connection when I'm streaming Netflix, but I do get a
>> high quality HD image with 5.1 sound with programmes that include it.
>
> The sound isn't the problem, it's the video. Sound is easily streamable.
> But I'm baffled as to how you can download video in anything approaching
> real-time, unless the quality is diabolically poor.
Except that it isn't. Part if it is called compression.
>> But more to the point, do you now understand what streaming is?
>
> Yes. Although I'm still puzzled as to how anybody could make money out
> of selling such poor quality stuff...
Convenience is a huge motivational driver for consumers. But more to the
point, most people don't see the quality as being "poor".
Jim
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On 2/2/2012 7:05, Invisible wrote:
> £3,000 for a new tape drive is actually /a crapload of money/. It
probably
When I first started at Bellcore, I joined during the budgeting time of
year. My manager asked "Do you foresee needing any equipment for your wor
k?"
I said "Well, I'll need a desktop computer of course." He says "No, I mea
n
equipment. Anything over $50K? If so, we need to budget it." :-)
That said, google does everything with such redundancy that it's not a
question of spending $3K to buy a tape drive, but a question of how many
$3K
tape drives you need to buy to back up 3 petabytes/day of data[*] and how
long are those drives going to last before you need to replace them,
factoring the salaries of the guys doing the fixing and the writing of th
e
code to allocate tapes to data. ([*] All numbers ass-pulled, mind.)
> How is that even *possible*? It's not like you can just go to the hardw
are
> store and buy 25km of copper wire and then put it into the ground with
a
> shovel on your day off or something...
That's exactly what the companies that do this for a living do.
--
Darren New, San Diego CA, USA (PST)
People tell me I am the counter-example.
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On 2/2/2012 2:05, Invisible wrote:
>> How is that not telling you what it is?
>
> HTML is "a family of formats used to publish works [frequently updated or
> not] in a standardized format". As is PDF. As is PostScript. How is RSS
> different?
Well, maybe you need to read the *second* sentence, hmm?
--
Darren New, San Diego CA, USA (PST)
People tell me I am the counter-example.
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> I have absolutely never
> had to use the $ key on my keyboard, unless I was programming in Perl.
This comment makes the whole discussion worth it! :-D
>>> "In another building" DOES NOT mean "over the Internet". Private data
>>> circuits predate the internet, and no company would use the Internet to
>>> link two data centres together.
>>
>> How is that even *possible*? It's not like you can just go to the
>> hardware store and buy 25km of copper wire and then put it into the
>> ground with a shovel on your day off or something...
>
> You don't do it yourself, unless you are in a campus environment and can
> easily rip up the parking lot and lay down your own fibre or copper.
>
> Step 1. Call your telco rep and order a circuit between site A and site A.
> Step 2. Telco will forward the request to a planner who will determine
> if the existing cabling between both sites and central offices (CO) has
> enough available bandwidth.
> Step 3a. If not, the planner will forward the request to their
> infrastructure group who will get diging permits from the
> city/county/whatever and lay down new bundles of cables.
> Step 3b. If the answer is yes, or once the new cables have been laid,
> the telco planner will forward your request to an enabler who will
> configure the CO switches to map the circuit from Site A's demarcation
> point to Site B's demarcation point.
> Step 4. Technicians will come on site, at both locations, and terminate
> the circuit from their demarc point to the exact rack you ask them to.
> Step 5. You plug in the circuit in your equipment (router, switch, or
> mainframe front-end-processor, to name a few)
>
> Tada!
>
> Usually, all of this is done for a small nominal fee. Any work they have
> to do between demarc points will be undertaken at their own expense,
> which they will recoup on your monthly usage bill, of course.
>
> By the way, if you ordered an "internet" link, the exact same steps
> would have to take place, except that they would be duplicated for site
> A to ISP and ISP to site B, and then the ISP would add its own routers
> at both ends and charge you twice as much and more for the "managed
> services".
Think is, if you order an Internet link, the telco has to run a few
hundred yards of cable to the nearest junction box at one end, and a few
hundred yards at the other end. If you want a dedicated circuit from one
end to the other without going via the Internet, they have to run
several miles of cable just for you. Who the /hell/ can afford that? o_O
>>> So their backup strategy will fail. Not the actual SAN. Gotcha.
>>
>> Well, given that backup is what this SAN is *for*, I guess I mixed up
>> the two things.
>
> I thought the SAN would replace some of the servers' internal disks. Sorry.
Actually, I am now 100% sure what the plan is here. Certainly the /main/
function of the SAN is routine data backup. I'm unsure whether we're
also going to use it for online storage too. (Hey, why would they tell
*me* such things? I'm only the person who's going to be running it...)
>> OK, so a major /bank/ can also accord crazy technology. None of this
>> alters the fact that the next tiny company I end up working for won't be
>> able to afford this kind of thing.
>
> What makes you think you can't find work in a large company?
1. How many large companies are there? How many small companies are
there? Exactly.
2. How many people apply to each large company? How many people apply to
each small one?
To be sure, it's not /impossible/ to work for a large company. Just less
likely.
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