So I’m studying for my Amazon Web Services Associate Architect ticket at the moment and, in the coursework I’m doing, I came across this really neat feature in AWS.

If you’re on an  EC2 instance (a VM), and you do..

$ curl http://169.254.169.254/latest/meta-data

You get a whole load of metadata back, like this..

ami-id
ami-launch-index
ami-manifest-path
block-device-mapping/
events/
hostname
iam/
identity-credentials/
instance-action
instance-id
instance-life-cycle
instance-type
ipv6
local-hostname
local-ipv4
mac
managed-ssh-keys/
metrics/
network/
placement/
profile
public-hostname
public-ipv4
reservation-id
security-groups
services/

All you need to do now is pick any of these sub-topics and query it again…

curl http://169.254.169.254/latest/meta-data/local-hostname

and you get

ip-10-16-57-144.ec2.internal

or query

curl http://169.254.169.254/latest/meta-data/instance-type

ans you get

t2.micro

Nice huh?  As the feature is a URL, then you can be sure you can query it from a Flask or NodeJS app directly so an app can now be aware of what kind of hardware it’s running on, so you could even have an app that would report in telemetry to a central server to let developers know about the characteristics of the host in relation to the app performance.  Quite a neat piece of internal architecture.

Nice.

This is something I’ve always know about in the back of my mind when planning systems.  Chaining critical path dependencies can be problematic if there’s a fault somewhere and, if it can go wrong at exactly the wrong time, it probably will.  I’m always a fan of having a Plan B because there’s no better feeling than being able to jettison a work stream and move to a more direct approach.

Funny enough, I wandered right into this concept just now and thought I’d post something about it because it has actually been essentially postulated already.  Ladies and gentlemen, I present to you, the “Fallacies of distributed computing“.

They are…

• The network is reliable
• Latency is zero
• Bandwidth is infinite
• The network is secure
• Topology doesn’t change
• There is one administrator
• Transport cost is zero
• The network is homogeneous

In many ways, the wider concept is that, as humans, our understanding of pretty much everything is wrong.  Why?  Well, nobody can have 100% of the information on a subject matter at any one time, whether that’s prices, markets, commodities, people or their intentions.  As any part of that information could prove critical, it’s absence means you are de facto misinformed.

You’re potentially the victim of misinformation depending on what you then do based on the (mis)information given.

I think this is the reason I’ve always been a fan of working with what I would call conscientious objectors in a team.  People who will always argue the contrarian point.  It’s a klaxon that can help people wake from their tendency to group-think and over-comply.  Getting something done is not just always about repeating what we did the last time.  Great as a template, sure, but this time around?  As any environment changes, real-world or digital, so too do the possible new tools available, newer methods, better people, and the realisation that our thinking has been way too small from the start.

So, bottom line?  It pays to remind yourself how little you know.

Men landed on the moon 48 years ago. The technology is still stunning. I still find it incredible that all this was achieved with computing power you would easily find in a contemporary washing machine, toaster or a digital watch; indeed, the microprocessors or microcontrollers in such equipment have far more power and cost anywhere up to $2 a piece.

With that in mind, here’s some superbly immersive websites that sync all the video and audio as well as stills of the lunar landings.

This is the complete landing sequence of Apollo 11 with audio and visual synced. Superb.
http://www.firstmenonthemoon.com/

This is a continuous loop of of Apollo 17 from launch to life on the lunar surface with photos and video. Again, superb.
http://apollo17.org

And then fast forward to today. Space-X is launching rockets that dump the payload into orbit and then the fist stage rocket section falls back to earth and lands vertically on the landing pad, ready for repair and re-use. Off. The. Hook.

“The Falcon has landed” | Recap of Falcon 9 launch and landing

Longer sequence of events

Pretty sick.

Check out this tweet form Mr. Edward Snowden.  Interesting indeed.  PGP still looks intact in its raw form.  This is good news.  Assuming the end point device has not been compromised of course and the password and private key snarfed.

That said, that is something really only a state player or well financed operative will have a shot at.  For the regular folk using PGP means always having your thoughts and ideas protected.

If somebody gets access to your mail server, as per Hillary Clinton, at least the attacker will have squigabytes worth of nothing and nobody finds out about your involvement with Saudi, mis-handling classified documents, Libya and the Clinton Foundation.

Your email was intercepted.  Two words.  “Shit” and “Jack”.

Here’s an interesting one.  I did not know that the term ‘patch’ as used to mean “apply an update to software” comes from the first computers.

In the days of punched paper tape, where binary commands were loaded into memory from tape, instead of recreating an entire punched paper tape to correct the software, a piece of sticky tape was applied to the paper tape to cover the hole in the paper and change the command, thus literally patching the software.

Moar info from wikipedia..

I saw this the other day while looking at the TV series “Mad Men”.  Everybody deserves to do a presentation to clients once in their lives and smash it this hard.  A demonstration of the killer Don Draper pitch.  TV perfection.

From Mad Men, Series 1, episode 13.