Alexmatchneer.com

Front 1

What is the name of the latest JS build tool that uses trees as a first class primitive for describing file transformations.

Back 1

Broccoli

Hint 1

http://alexmatchneer.com/blog/2014/04/12/ember-cli-and-npm-fights

Front 2

Run this command inside a node project folder to install its binaries to your system

Back 2

npm link

Hint 2

http://alexmatchneer.com/blog/2014/04/12/ember-cli-and-npm-fights

Front 3

This is the state machine compiler that backs the Mongrel HTTP parsing engine

Back 3

Ragel (http://www.complang.org/ragel/)

Hint 3

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 4

Joyent's parser written in C was taken from this server's codebase

Back 4

nginx

Hint 4

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 5

Who was the author of nginx?

Back 5

Igor Sysoev

Hint 5

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 6

This Ruby server combines the Mongrel HTTP parser, Event Machine, and Rack, and can be configured to enable threading.

Back 6

Thin (http://code.macournoyer.com/thin/)

Hint 6

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 7

The author of Mongrel

Back 7

Zed Shaw

Hint 7

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 8

Is Puma the only multi-threaded Rails 4 HTTP server?

Back 8

No, there's Net::HTTP::Server, Phusion Passenger 4, Rainbows!, Reel, Thin, Webrick, Zbatery (http://stackoverflow.com/questions/17902386/is-puma-the-only-multi-threaded-rails-4-http-server)

Hint 8

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 9

A fork-less HTTP Rack server based on Rainbows! -> Unicorn -> Mongrel and inherits parts of each, supporting thread/fiber/event/actor concurrency (just not threads)

Back 9

Zbatery (http://zbatery.bogomip.org/)

Hint 9

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 10

Based on Unicorn, this HTTP Rack server is designed for applications that expect long request/response times and/or slow clients

Back 10

Rainbows! (http://rainbows.rubyforge.org/)

Hint 10

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 11

For Rack applications not heavily bound by slow external network dependencies, consider this instead as it simpler and easier to debug.

Back 11

Unicorn

Hint 11

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 12

If you're on a small system, or write extremely tight and reliable code and don't want multiple worker processes, check out XXXXX, too. XXXXX can use all the crazy network concurrency options of Rainbows! in a single worker process.

Back 12

Zbatery (http://rainbows.rubyforge.org/ and http://zbatery.bogomip.org/)

Hint 12

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 13

A website that mocks a slow API

Back 13

http://slowapi.com/ - e.g. curl http://slowapi.com/delay/1.0

Hint 13

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 14

Asynchronous HTTP Client (EventMachine + Ruby)

Back 14

em-http-request (https://github.com/igrigorik/em-http-request)

Hint 14

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 15

A HTTP client lib with a common interface over many adapters (e.g. Net::HTTP, Excon, EventMachine, etc), with a Rack-like middleware system

Back 15

Faraday (https://github.com/lostisland/faraday)

Hint 15

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 16

This command line tool from Apache benchmarks a server's response time

Back 16

ab -n 600 -c 200 http://mycoolasync.herokuapp.com/async_test

Hint 16

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 17

Fully async real-time web app Ruby framework. Built on top of EventMachine, designed for large number of open connections and providing full-duplex bidirectional communication.

Back 17

Cramp (http://cramp.in/)

Hint 17

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 18

What does full-duplex mean?

Back 18

It means transmitted data does not appear to be sent until it has actualy been received and acked by other party.

Hint 18

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 19

What is the difference between a thread and a fiber?

Back 19

Thread execution can be interrupted at any time (preemption), possibly leaving data an unsafe/unfinished state. Fibers are "cooperative", and cannot be preempted, and must explicitly yield to give up control.

Hint 19

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 20

The Reactor Pattern

Back 20

A single-threaded queue, all IO shoved into kernel thread, rejoin single-threaded reactor queue when it's done.

Hint 20

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 21

Python's Reactor pattern solution

Back 21

Twisted

Hint 21

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 22

Ruby's Reactor pattern solution

Back 22

EventMachine

Hint 22

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 23

Java's Reactor pattern solution

Back 23

JBoss_Netty

Hint 23

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 24

PHP's Reactor pattern solution

Back 24

Non-existent

Hint 24

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 25

Ruby library of convenience classes to untangle evented code, allowing you to write code in a non-callback-y manner.

Back 25

em-synchrony (https://github.com/igrigorik/em-synchrony)

Hint 25

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 26

OSS version of non-blocking (async) Ruby web server powering PostRank. Uses Ruby 1.9 fibers to de-callback-ify your code

Back 26

Goliath (http://postrank-labs.github.io/goliath/)

Hint 26

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 27

Nginx, Beanstalkd, EventMachine, Twisted, Node.js are all examples of servers that embrace this pattern

Back 27

Reactor pattern (http://www.igvita.com/2010/03/22/untangling-evented-code-with-ruby-fibers/)

Hint 27

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 28

What word describes the act of interrupting a task without its cooperation? How does this term apply to the various concurrency models?

Back 28

Preemption. Threads can be pre-empted (except user-space threads). Fibers cannot.

Hint 28

http://alexmatchneer.com/blog/2014/04/21/daily-journal

Front 29

What is `ignoredModules` useful for in the `broccoli-es6-concatenator` plugin?

Back 29

It prevents a file from being transpiled, and basically marks a module as something that'll be implemented later

Hint 29

http://alexmatchneer.com/blog/2014/04/28/daily-journal

Front 30

Why explicitly set constructor when creating a JS subclass?

Back 30

Because otherwise constructor will refer to parent class constructor

Hint 30

http://alexmatchneer.com/blog/2014/04/26/daily-journal

Front 31

RSA

Back 31

Encryption key is public, decryption secret. Used for generating symmetric key in TLS

Hint 31

http://alexmatchneer.com/blog/2014/05/01/daily-journal-2

Front 32

Query param for telling QUnit to grep module names

Back 32

filter=wat

Hint 32

http://alexmatchneer.com/blog/2014/05/01/daily-journal-2

Front 33

denormalize

Back 33

Adding duplication/redundancy to a system, e.g. storing a person's first name in multiple tables, often for the purpose of optimization

Hint 33

http://alexmatchneer.com/blog/2014/05/01/daily-journal

Front 34

quick way to stub out a Ruby method so that it accepts any number of args

Back 34

def meth(*args)

Hint 34

http://alexmatchneer.com/blog/2014/05/01/daily-journal

Front 35

Fight nils by using this Hash/Array accessor instead

Back 35

Hash#fetch or Array#fetch (note that there is no Enumerable#fetch)

Hint 35

http://alexmatchneer.com/blog/2014/05/01/daily-journal

Front 36

Command to change directories, saving the current location

Back 36

pushd /some/place; popd

Hint 36

http://alexmatchneer.com/blog/2014/05/01/daily-journal

Front 37

Vim: surround a word in ']'

Back 37

vsiw]

Hint 37

http://alexmatchneer.com/blog/2014/05/04/daily-journal

Front 38

Vim: surround a chunk word in ']'

Back 38

vsiW]

Hint 38

http://alexmatchneer.com/blog/2014/05/04/daily-journal

Front 39

Vim: change surrounding ' to "

Back 39

cs"'

Hint 39

http://alexmatchneer.com/blog/2014/05/04/daily-journal

Front 40

Vim: delete surrounding "

Back 40

ds"

Hint 40

http://alexmatchneer.com/blog/2014/05/04/daily-journal

Front 41

Vim: wrap line in parens

Back 41

yss(

Hint 41

http://alexmatchneer.com/blog/2014/05/04/daily-journal

Front 42

Design principles: How can TDA and SRP conflict?

Back 42

Either you stuff all the things that the User class can handle in user domain-specific terms (which breaks Single Responsibility Principle), or you add additional classes that know enough about User to ask it for property and values and make transformations/decisions based on that knowledge (which breaks Tell Don't Ask)

Hint 42

http://alexmatchneer.com/blog/2014/05/04/daily-journal

Front 43

Quick way to mark an rspec test as pending

Back 43

change `it` to `xit`

Hint 43

http://alexmatchneer.com/blog/2014/05/04/daily-journal

Front 44

Cisgender

Back 44

aka cissexual; a person whose gender matches that assigned at birth

Hint 44

http://alexmatchneer.com/blog/2014/05/04/daily-journal

Front 45

HAL

Back 45

Hypermedia Application Language; missing some features that make json api rad

Hint 45

http://alexmatchneer.com/blog/2014/05/04/daily-journal

Front 46

=== in Ruby

Back 46

subsumption or case equality operator; overridden by context-specific subclasses. Module#=== will return true if passed an object that has included that module

Hint 46

http://alexmatchneer.com/blog/2014/05/12/daily-journal

Front 47

Uniform Type Identifiers

Back 47

Apple's system for uniquely describing a type, using reverse domain name notation

Hint 47

http://alexmatchneer.com/blog/2014/05/15/daily-journal

Front 48

Reverse domain name notation

Back 48

e.g. com.alexmatchneer.StringBuffer; allows for more sensible sorting

Hint 48

http://alexmatchneer.com/blog/2014/05/15/daily-journal

Front 49

LevelDB

Back 49

library (as opposed to database server) that provides kv storage; can wrap in an app via C++ API

Hint 49

http://alexmatchneer.com/blog/2014/05/15/daily-journal

Front 50

Shift V in Vim

Back 50

Visual line mode; select whole lines

Hint 50

http://alexmatchneer.com/blog/2014/05/15/daily-journal

Front 51

GlobalId

Back 51

ActiveModel GlobalID: a way of serializing a model into a string so that it can be looked up by some later process

Hint 51

http://alexmatchneer.com/blog/2014/05/19/daily-journal

Front 52

var a = 'A'; a.foo='wat';

Back 52

This doesn't work in use strict, breaks in Safari

Hint 52

http://alexmatchneer.com/blog/2014/05/19/daily-journal

Front 53

What's the difference between array and reduce computed properties?

Back 53

Reduce CPs can reduce to anything you want, either a single value or an array. Array CPs are instances of reduce CPs that always return arrays.

Hint 53

http://alexmatchneer.com/blog/2014/05/22/daily-journal

Front 54

Variable Timing

Back 54

Messaging, as opposed to synchronous communication (e.g. RPC/RPI), doesn't peg the sender's performance time on the receiver's performance time, e.g. a sender isn't just as fast as the receiver

Hint 54

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 55

Throttling

Back 55

RPC/RPI can overload a receiver if too many come in at the same time; messaging involves queues == throttling

Hint 55

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 56

Reliable Communication

Back 56

Storing the message means retrying, handling failures.

Hint 56

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 57

Disconnected Operation

Back 57

Offline apps can use messaging to queue data to sync when reconnected

Hint 57

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 58

Mediation

Back 58

Mediator pattern from GoF; if an app gets disconnected from others, it only needs to reconnect to the single messaging system

Hint 58

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 59

Thread Management

Back 59

Because async, threads no longer blocked on a response (unless they want / need to be)

Hint 59

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 60

CORBA

Back 60

Common Object Request Broker Architecture: a platform-neutral RPC spec

Hint 60

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 61

n-tier

Back 61

(multi-tier): client-server architecture in which presentation, application processing, and data management are physically separated; 3-tier is most common; some similarities w MVC? Also, n-tier is distribution, not integration.

Hint 61

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 62

git predecessor

Back 62

BitKeeper, no longer free of charge in 2005.

Hint 62

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 63

git checksum

Back 63

SHA-1 hash

Hint 63

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 64

`git add` will store things in...

Back 64

.git/objects

Hint 64

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 65

3 locations for git config

Back 65

/etc/gitconfig, ~/.gitconfig, .git/config

Hint 65

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 66

git bakes this into your commits

Back 66

user.name and user.email

Hint 66

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 67

git config a.b.c lol

Back 67

puts [a "b"]
c = lol in .git/config

Hint 67

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 68

what config is totally necessary to use git?

Back 68

user.name and user.email

Hint 68

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 69

git globs files

Back 69

so you can do git add log/\*.log

Hint 69

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 70

git log with diff

Back 70

git log -p (the p stands for patch)

Hint 70

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 71

git log limit to 2

Back 71

git log -2

Hint 71

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 72

difference b/w git author and committer

Back 72

author wrote the code, committer merged or applied to repo

Hint 72

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 73

can only push to this kind of git url

Back 73

SSH URL, e.g. [e-mail]:machty/ember.js

Hint 73

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 74

command to display lots of live info about a remote

Back 74

git remote show origin

Hint 74

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 75

difference between lightweight and annotated tags

Back 75

lightweight just points to a commit; annotated are full git objects, checksummed, contain tagger name, message, can be GPG (GNU Privacy Guard) signed

Hint 75

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 76

how to annotate tag

Back 76

git tag -a v1.4 -m lol

Hint 76

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 77

command to inspect a tag for more info

Back 77

git show tagname

Hint 77

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 78

GPG signed tag

Back 78

git tag -s v3.0 -m haha

Hint 78

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 79

tag previous commit

Back 79

git tag v.retro shortsha

Hint 79

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 80

How many chars is a short sha?

Back 80

any number of chars so long as it can be matched to a longer one

Hint 80

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 81

how to push a single tag?

Back 81

git push tagname

Hint 81

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 82

how to add git auto complete

Back 82

you need bash, source gitrepo/contrib/completion/completion-something.bash

Hint 82

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 83

shorthand for declaring a git alias

Back 83

git config --global alias.something 'reset --HEAD'

Hint 83

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 84

what's in a git commit?

Back 84

pointer to snapshot, author, message, 0+ pointer to parent commits

Hint 84

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 85

HEAD

Back 85

pointer to the branch you're currently on

Hint 85

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 86

When can you fast forward?

Back 86

When the current branch head is an ancestor of the named commit. You're literally just moving a pointer.

Hint 86

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 87

Upstream

Back 87

The originator of the data, which flowed to you at some point, e.g. when you cloned a repo, or you created a branch.

Hint 87

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 88

What are the 3 components of a 3-way-merge?

Back 88

Common ancestor, current HEAD, and to-be-merged branch.

Hint 88

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 89

What's unique about a merge commit?

Back 89

It has more than one parent.

Hint 89

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 90

show all branches and last commit for each

Back 90

git branch -v

Hint 90

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 91

Show merged / unmerged branches

Back 91

git branch --merged ; git branch --no-merged

Hint 91

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 92

git push origin master expand to...

Back 92

git push origin refs/heads/master:refs/heads/master

Hint 92

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 93

command to create a new branch starting off of another one

Back 93

git checkout -b newbranch existingbranch

Hint 93

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 94

`git branch -d branch to delete` will yell at you under this circumstance

Back 94

it's not merged into the current branch

Hint 94

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 95

what happens if you do `git checkout origin/some-remote-branch`?

Back 95

Detached head state. To create a tracking branch, do `git checkout localbranch origin/some-remote-branch`

Hint 95

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 96

tracking branch

Back 96

a local branch that have a direct relationship to a remote branch; `git push` and `git pull` will go to the tracking branch

Hint 96

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 97

another way to write `git checkout foo origin/foo`

Back 97

`git checkout --track origin/foo`; creates local foo tracking origin/foo

Hint 97

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 98

Delete remote branch foo

Back 98

git push origin :foo; remember: `git push origin [localbranch]:[remotebranch]`

Hint 98

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 99

dog-ear

Back 99

bend a page to make it easily findable later

Hint 99

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 100

The rule for when _not_ to rebase

Back 100

Don't rebase commits that you've pushed to a public repo

Hint 100

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 101

difference b/w `git clone /path/to/repo` and `git clone file:///path/to/repo`

Back 101

`file:///` uses the remote file transfer stuff that it would use for anything remote, whereas direct path directly copies and uses hard links and what not; `file:///` gives you a more pristine copy, less junk

Hint 101

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 102

limitation of SSH repo access

Back 102

no anonymous access, possibly bad for open source

Hint 102

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 103

git protocol

Back 103

daemon packaged w git but w no authentication; no pushing (in general, since it opens to the door to anyone)

Hint 103

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 104

Speed of git protocol relative to SSH

Back 104

way faster since no authentication and encryption overhead

Hint 104

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 105

solution to SSH non-anonymity and git non-auth

Back 105

configure server to use both; git protocol for cloner/pullerss, ssh for repo write access homies

Hint 105

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 106

git command to init a bare repo in folder foo

Back 106

`git init --bare foo`

Hint 106

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 107

after creating a bare repo and running http server, git clone fails. Why? How to fix?

Back 107

HTTP hosting implies you have static files to serve, but these don't magically exist by default. They can be generated via the post-update.sample hook, which runs `git update-server-info`. You can either manually run this or enable the hook and push to it once (not via HTTP)

Hint 107

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 108

start a ruby server hosting files in this directory

Back 108

`ruby -run -e httpd . -p 5001`

Hint 108

http://alexmatchneer.com/blog/2014/05/24/daily-journal

Front 109

API for growl-esque notifications in websites

Back 109

Web Notifications

Hint 109

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 110

Conway's law

Back 110

Organizations which design systems are constrained to produce designs which are copies of the communication structures of these organizations

Hint 110

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 111

Information Portal

Back 111

Aggregation of multiple sources of information into a single display

Hint 111

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 112

Data Replication

Back 112

e.g. user's address may be redundantly stored in many places, but needs to be updated if they change it in one, which requires integration

Hint 112

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 113

Shared Business Function

Back 113

Multiple components need to perform the same operation; integration means exposing this one thing as an integrated service

Hint 113

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 114

Service-Oriented Architecture

Back 114

a Service is well-defined function that responds to requests from Service Consumers. 1. Needs a service directory for discovery. 2. Each service needs to describe its API.

Hint 114

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 115

Distributed Business Process

Back 115

Mediator; one component handles the coordination of a single business process among many other components.

Hint 115

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 116

Business-to-business integration

Back 116

Basically, all the above, but not restricted to within a single enterprise (business). So you might use a 3rd party company to calculate shipping rates

Hint 116

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 117

Loose coupling tradeoff

Back 117

The more assumptions can be made, the more efficient the communication, but the more brittle in response to change or interruptions

Hint 117

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 118

Making remote invocations feel like local calls

Back 118

RPC/RMI

Hint 118

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 119

RPC/RMI difference?

Back 119

RPC is C-based, not necessarily object oriented. RMI is method / OO-based

Hint 119

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 120

RPC/RMI Advantage

Back 120

1. Local invocation well-established and familar. 2. Defer the design decision to make a procedure call remote or local.

Hint 120

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 121

RPC/RMI Fail

Back 121

Waldo et al in 1994 reminded us that object interaction in distributed system fundamentally different; so many things can fail/mismatch, how to recover, what if args mismatch, etc.

Hint 121

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 122

EIP: Problems w just transmitting TCP/IP bytes to request deposit

Back 122

1. converting integer bits has incompatibility w different number representations, 2. big-ending / little-endian. 3. brittle if destination changes, or needs to go to multiple destinations. 4. TCP/IP is connection-oriented, so both machines must be present at the same time. 5. Data format changes requires updating both server and client

Hint 122

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 123

EIP: Solutions to TCP

Back 123

1. XML for self-description and platform-independence. 2. Use named channel rather than hard-wired hostname. 3. Queue up sent messages so that receiver doesn't need to be online to send messages. 4. Channel can convert messages in case either side changes.

Hint 123

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 124

MOM

Back 124

Message-oriented middleware, handles sending and receiving messages b/w distributed systems

Hint 124

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 125

Sneakernet

Back 125

Transfer of data by physically moving the stored data from one place to another, because you wear sneakers to get it from a to b.

Hint 125

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 126

EIP: Channel

Back 126

How data gets from A to B, e.g. TCP/IP connections, shared file, shared DB, floppy disk + Sneakernet

Hint 126

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 127

EIP: Message

Back 127

snippet of data with agreed-upon meaning to both sides; format may be different, but intent/meaning is the same

Hint 127

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 128

EIP: Translation

Back 128

translate FIRST_NAME and LAST_NAME fields to Customer_Name, etc.

Hint 128

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 129

EIP: alternative to having customer service broadcast address changes to everyone else

Back 129

Have a routing component (e.g. a message broker) split the message to many components

Hint 129

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 130

EIP: the thing that monitors what's going on inside the entire system

Back 130

Systems management; monitors flow, makes sure all apps and components up and running, reports errors to central location

Hint 130

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 131

EIP: message endpoint

Back 131

connects a system explicitly to an integration solution; useful for legacy code

Hint 131

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 132

Process Manager (two responsibilities)

Back 132

1. storing data b/w messages (inside a 'process instance'). 2. Keeping track of progress and determining the next step (by using a 'process template')

Hint 132

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 133

React and Object.observe

Back 133

At odds, because the re-render everything upon change doesn't take advantage of the fact that Object.observe is a thing that will tell us exactly what changed and what needs to be re-rendered

Hint 133

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 134

NIH (also, what's the antonym?)

Back 134

Not invented here; antonynm: Proudly Found Elsewhere

Hint 134

http://alexmatchneer.com/blog/2014/05/25/daily-journal

Front 135

4 Application Integration Options

Back 135

1. File transfer. 2. Shared Database. 3. Remote Procedure Invocation. 4. Messaging

Hint 135

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 136

EIP: freshness

Back 136

File-based integrations have staleness considerations; e.g. process address change at night, but a shipment happened that day after the request. Also, the longer the length of time to sync, the more conflicts can sneak in.

Hint 136

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 137

File Transfer relative to Messaging

Back 137

High-frequency file transfer is like messaging, but way inefficient, error prone, etc. Similarities include storage, fire and forget, etc.

Hint 137

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 138

Semantic dissonance

Back 138

aka conceptual impedance mismatch e.g. two very similar seeming applications have subtly different specific definitions of a concept that can result in differing implementations

Hint 138

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 139

Political considerations of shared DB

Back 139

Challenging/delaying to conform multiple applications to a single schema, irresistible pressure to split

Hint 139

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 140

Shared DB limitations

Back 140

External packages have their own schemas which also might change b/w versions; company merges occur later, thwarting the previously consolidated plan.

Hint 140

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 141

When to use RPI?

Back 141

To integrate application's functionality rather than data.

Hint 141

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 142

WSDL

Back 142

Web Services Description Language; XML-based description of a service: expected params, structure of data produced, error format

Hint 142

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 143

UDDI

Back 143

Universal Description, Discovery, and Integration; dictionary of WSDLs

Hint 143

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 144

SOAP

Back 144

simple object access protocol; XML-based protocol for structuring messages to web services

Hint 144

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 145

List of RPC implementers

Back 145

CORBA, COM, .NET Remoting, Java RMI

Hint 145

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 146

RPI's familiarity w normal method invocations has this weakness

Back 146

Familiarity conceals major performance/reliability implications

Hint 146

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 147

RPI relative to Messaging suffers from ______

Back 147

Tight coupling; interfaces are designed for specific applications, not resilient to change

Hint 147

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 148

Cohesion / Adhesion

Back 148

(in regards to working w remote applications) cohesion is local work and adhesion is remote queries

Hint 148

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 149

to avoid or not to avoid semantic dissonance

Back 149

a corporate merger or necessary integration w 3rd party software is going to require it anyway, so best to address the issue w messaging rather than design applications that avoid it

Hint 149

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 150

How do you transfer packets of data?

Back 150

Sender sends a Message via a Message Channel that connects sender and receiver

Hint 150

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 151

How do you know where to send the data?

Back 151

Sender can send to Message Router, and it can decide

Hint 151

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 152

How do you know what format of data to send?

Back 152

If sender/receiver can't agree, sender can send to Message Translator, which translates and forwards

Hint 152

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 153

If you're an app dev, how do you connect your app to messaging system?

Back 153

Implement Message Endpoints to perform sending and receiving

Hint 153

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 154

Message Channel

Back 154

Virtual pipe that connects sender and receiver; newly installed messaging systems typically don't contain any; up to you to define for application's need

Hint 154

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 155

Pipes and Filters

Back 155

Any validations/transformations/etc that happen b/w sender and receiver

Hint 155

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 156

Endpoints (messaging)

Back 156

Layer of code in an application that touches both app and messaging code; a bridge between worlds

Hint 156

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 157

Message consists of N parts:

Back 157

1. Header (origin, destination, describes data). 2. Body, generally ignored by system and simply transmitted onward

Hint 157

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 158

HEAD in git

Back 158

a reference to the currently checked-out commit

Hint 158

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 159

Abstract Pipe

Back 159

an interface for IO (such as used by filters) that could either be local memory or a full on Message Channel

Hint 159

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 160

Potential downside of Filters and Pipes

Back 160

Each pipe is a connector between filters, and if implemented via a Message Channel could consume much memory and CPU cycles for storage, translation, etc

Hint 160

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 161

Throughput and Filters

Back 161

Filters with their own thread/process and connected via async cross-process/cross-thread channels can achieve higher throughput, pipeline style

Hint 161

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 162

Parallelize

Back 162

(vs. sequential); add more instances of a some process working at the same time; multiply process X by N so that as input comes in, one of the N processes can process it

Hint 162

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 163

Filter overloading

Back 163

Filter can mean 1. a step in a process that applies some logic / transformation, or 2. something that removes data from a set based on some criteria

Hint 163

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 164

predictive / reactive routing

Back 164

Message Router knows destinations vs Pub Sub channel consumers choosing themselves

Hint 164

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 165

Failover

Back 165

Automatic switching to redundant system in case of failure

Hint 165

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 166

Content-based routing

Back 166

Routing based on message content

Hint 166

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 167

Context-based routing

Back 167

Routing based on environmental conditions, e.g. load balancing, etc.

Hint 167

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 168

Message Channels and load-balancing

Back 168

Rather than using a router for load-balancing, you might already have load balancing if Competiting Consumers are pulling messages off of a channel as fast as they can; tradeoff is that Message Routers have more information to make this decision

Hint 168

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 169

Round robin

Back 169

maintaining a list of output channels (could be ip addresses) and cycling through them in some manner

Hint 169

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 170

Live update a router

Back 170

Using a Control Bus

Hint 170

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 171

Integration equivalent of GoF Mediator

Back 171

Message Broker

Hint 171

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 172

HTTP

Back 172

Hypertext Transfer Protocol; application protocol

Hint 172

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 173

Application Protocol

Back 173

Sit on top of transport layer. Controls message body format to do application-specific things without having to be concerned about TCP/IP considerations, etc

Hint 173

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 174

HTTP is this kind of protocol

Back 174

application-layer

Hint 174

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 175

Internet protocol suite

Back 175

More commonly known as TCP/IP. Transmission Control Protocol + Internet Protocol

Hint 175

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 176

SOAP and caching

Back 176

SOAP is shitty at caching because resources are not a first class concept like they are in REST, which deprives of verbs

Hint 176

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 177

transport vs transfer

Back 177

The dumb/blind carrying of data from A to B (transport) vs (transfer) the consideration of message content / what's being sent to effectively process the transfer. HTTP is transfer, evidence of this is all its verbs and status codes.

Hint 177

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 178

XSL

Back 178

Extensible Stylesheet Language: family of languages to transform and render XML docs (XSLT, XSL-FO, XML Path)

Hint 178

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 179

ActiveX

Back 179

Microsoft framework that adapts earlier Component Object Model

Hint 179

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 180

Create an XML doc in JS

Back 180

document.implement.createDocument()

Hint 180

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 181

SGML

Back 181

Standard Generalized Markup Language; derivatives include XML and HTML

Hint 181

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 182

XML rel to SGML

Back 182

subset of features to allow for easier parsing among other things

Hint 182

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 183

DOMString

Back 183

UTF-16 string; JavaScript already uses these, so a DOMString is just String. (there is no DOMString class in JS)

Hint 183

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 184

XML Namespace

Back 184

A URI, e.g. URL for the author's webpage, e.g. http://www.w3.org/1999/xhtml. The URI/URL doesn't need content, just uniquely refers to that spec

Hint 184

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 185

set an Element's attribute in js

Back 185

element.setAttribute('onclick', alert('wat'))

Hint 185

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 186

Difference b/w Node and Element

Back 186

Nodes could be text nodes. Just nodes in trees. Elements are named, can have classes and IDs, etc. An Element IS a Node.

Hint 186

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 187

Inline event and translation

Back 187

onclick='alert("****")' becomes anonymous fn that gets `call`'d with clicked element as the context

Hint 187

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 188

DOM Level 0 events

Back 188

inline and traditional; only single handlers supported

Hint 188

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 189

Standardizes ECMAScript

Back 189

TC39

Hint 189

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 190

Standardizes Web Architectures

Back 190

W3C TAG (Technical Architecture Group)

Hint 190

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 191

Mr. Promises is a member of ...

Back 191

W3C Tag

Hint 191

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 192

Rick Waldron is member of ...

Back 192

W3C Tag

Hint 192

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 193

Yehuda Katz is member of ...

Back 193

TC39 and W3C TAG

Hint 193

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 194

iOS click events

Back 194

don't bubble up to document, unless 1. native button/link clicked, 2. handler explicitly added, 3. cursor: pointer (which prevents copy/paste from working as expected)

Hint 194

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 195

Start of xml doc

Back 195

<?xml version="1.0" encoding="UTF-8"?>

Hint 195

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 196

XSLT is a member of this family of languages

Back 196

XSL, extensible stylesheet language

Hint 196

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 197

XSLT

Back 197

Extensible stylesheet language transformations

Hint 197

http://alexmatchneer.com/blog/2014/05/26/daily-journal

Front 198

Message Endpoint

Back 198

code custom to application and messaging system's API

Hint 198

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 199

Magnet

Back 199

a url hashed by the content of the file it points to

Hint 199

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 200

btih

Back 200

BitTorrent Info Hash; SHA1 of the bitorrent metadata

Hint 200

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 201

When do CPs get overridden?

Back 201

When they're get only (CP fns have <= 1 arity)

Hint 201

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 202

Why is Ember.computed.reads in the docs

Back 202

Because defeaturify doesn't run before the API docs are generated (maybe that'll change?)

Hint 202

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 203

Difference b/w computed.defaultTo and the CP severing behavior

Back 203

defaultTo isn't a binding; it only retrieves the target defaultValue when the cur value is null

Hint 203

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 204

Coneheads antagonist

Back 204

Michael McKean

Hint 204

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 205

Thread.current[:a] = 5

Back 205

Store a=5 in Fiber-local var.

Hint 205

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 206

IEEE

Back 206

Institute of Electrical and Electronics Engineers; not-for-profit corporation, specified telephony, networking; produces 30% of world's literature on EE and CS

Hint 206

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 207

IEEE 802

Back 207

Family of standards dealing with LAN and metro area networks

Hint 207

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 208

WLAN standard

Back 208

IEEE 802.11; media access control (MAC) and physical layer (PHY)

Hint 208

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 209

IEEE 1003

Back 209

POSIX

Hint 209

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 210

POSIX

Back 210

Portable Operating System Interface (1988): family of standards specified by IEEE for maintaining compat b/w operating systems. POSIX defines API, command line shells and utilities, e.g. awk, echo, ed, threading lib

Hint 210

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 211

Holder of UNIX trademark

Back 211

Open Group

Hint 211

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 212

Linux and POSIX

Back 212

TODO

Hint 212

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 213

What is Linux?

Back 213

It's just a kernel; Linux distros are Linux kernel + lots of other utilities, mostly from GNU

Hint 213

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 214

Solaris

Back 214

Unix operating system originally by Sun, now by Oracle

Hint 214

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 215

What does it mean for an OS to be considered a 'Unix OS'

Hint 215

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 216

A free UNIX OS

Back 216

OpenSolaris

Hint 216

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 217

The X in OS X

Back 217

Signifies relationship to uniX

Hint 217

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 218

Logivision POS / LPOS users

Back 218

Union Market, Gourmet Garage

Hint 218

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 219

ruby: break x

Back 219

force the method that yielded me to return x

Hint 219

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 220

RSS (memory)

Back 220

Resident set size: portion of process's memory that is held in RAM, as opposed to swap or filesystem

Hint 220

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 221

Enumereable Lazy

Back 221

Ruby 2.0's ability to lazy eval what might be an infinite sequence; not eval'd until something like `to_a` called

Hint 221

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 222

Why couldn't Ruby pre 2.0 use OS COW semantics while forking?

Back 222

Because setting FL_MARK was rightfully interpreted as a write; bitmap marking got around this

Hint 222

http://alexmatchneer.com/blog/2014/05/28/daily-journal

Front 223

Stoma

Back 223

Smoker hole cut

Front 224

META_DESC

Back 224

The ES5 descriptor for the meta property on an object; non-enumerable and non-configurable

Hint 224

http://alexmatchneer.com/blog/2014/05/31/ember-meta

Front 225

EMPTY_META

Back 225

The read-only, empty meta object returned by `meta(obj, false)` when obj has no meta already

Hint 225

http://alexmatchneer.com/blog/2014/05/31/ember-meta

Front 226

How do I find all the properties that have property as a dep key?

Back 226

obj.meta.deps[changingPropName]

Hint 226

http://alexmatchneer.com/blog/2014/05/31/ember-meta

Front 227

What causes the forgetful consumption behavior of lazy observers?

Back 227

didChange on CP removes dependentKeys

Hint 227

http://alexmatchneer.com/blog/2014/05/31/ember-meta

Front 228

If CP#didChange removes dependent keys, who adds it back in template situations?

Back 228

The view that was installed will call get() on that CP, and .get() on a cacheable property will call addDependentKeys

Hint 228

http://alexmatchneer.com/blog/2014/05/31/ember-meta

Front 229

Why is it that an observer can be properly set up, but it doesn't look like it when you inspect the containing object?

Back 229

It might be declared on the prototype, which doesn't show up in Chrome by default. defineProperty on the obj itself would reveal `listeners`, but rest assured in the prototype, it exists

Hint 229

http://alexmatchneer.com/blog/2014/05/31/ember-meta

Front 230

Observers aren't lazy when observing static values, but only CPs... why?

Back 230

Static values have different rules... really the lazy CP behavior kicks in when you have Observer -> CP -> Depkey and nothing has consumed to CP, hence when the depkey changes, no change event fires unless someone has consumed cp

Hint 230

http://alexmatchneer.com/blog/2014/05/31/ember-meta

Front 231

Where do file descriptors live for subprocess file-y operator

Back 231

/tmp/fd

Hint 231

http://alexmatchneer.com/blog/2014/06/29/daily-journal

Front 232

Run a command, capture its output in a file descriptor

Back 232

<(echo wat)

Hint 232

http://alexmatchneer.com/blog/2014/06/29/daily-journal

Front 233

What happens if i just this command: `<(echo 'wat')`

Back 233

Permission denied, because <(echo 'wat') evaluates to a tmp/fd/3 path and is interpreted as attempted to execute a file, but it doesn't have these permissions

Hint 233

http://alexmatchneer.com/blog/2014/06/29/daily-journal

Front 234

`ps`, but with hierarchy

Back 234

`pstree`

Hint 234

http://alexmatchneer.com/blog/2014/06/29/daily-journal

Hint 235

http://alexmatchneer.com/blog/2014/06/29/daily-journal

Front 236

Capacity equation (bandwidth and signal-noise ratio)

Back 236

C (bits per sec) = BW (Hz) * log2(1 + S/N (watts))

Hint 236

http://alexmatchneer.com/blog/2014/07/05/daily-journal

Front 237

Total capacity (bits per sec) of wireless transitions is proportional to...

Back 237

Bandwidth (Hz)

Hint 237

http://alexmatchneer.com/blog/2014/07/05/daily-journal

Front 238

thrashing (vm)

Back 238

degradation of performance due to too much swapping/paging

Hint 238

http://alexmatchneer.com/blog/2014/07/05/daily-journal

Front 239

'zones' w.r.t Cocoa and alloc

Back 239

regions of memory; alloc'ing in the same zone may prevent virtual memory thrashing

Hint 239

http://alexmatchneer.com/blog/2014/07/05/daily-journal

Front 240

The two implicit vars provided when running a method in Objective C

Back 240

`self` and `_cmd`; `_cmd` is the message sent

Hint 240

http://alexmatchneer.com/blog/2014/07/05/daily-journal

Front 241

Pre-ARC approach for preventing thrashing in allocated Cocoa objects

Back 241

allocWithZone and -zone

Hint 241

http://alexmatchneer.com/blog/2014/07/05/daily-journal

Front 242

Cocoa: when do you use `finalize`?

Back 242

When you're using ARC and you have things like legacy allocated objects to release or file handles to close

Hint 242

http://alexmatchneer.com/blog/2014/07/05/daily-journal

Front 243

Hibernia Express

Back 243

London-New York underground cable for financial institutions; shave 5ms latency off, $80M per millisecond saved

Hint 243

http://alexmatchneer.com/blog/2014/07/08/daily-journal

Front 244

Four components of latency for a typical router

Back 244

Propagation delay, Transmission Delay, Processing Delay, Queuing Delay

Hint 244

http://alexmatchneer.com/blog/2014/07/08/daily-journal

Front 245

Propagation delay

Back 245

Time required to travel from A to B, bounded by speed of light

Hint 245

http://alexmatchneer.com/blog/2014/07/08/daily-journal

Front 246

Transmission delay

Back 246

Time required to push all packets onto the link, function of packet length and data rate

Hint 246

http://alexmatchneer.com/blog/2014/07/08/daily-journal

Front 247

Processing delay

Back 247

Time to process packet header, check for bit-level errors, and determine destination

Hint 247

http://alexmatchneer.com/blog/2014/07/08/daily-journal

Front 248

Queuing delay

Back 248

Time in router queue waiting to be processed

Hint 248

http://alexmatchneer.com/blog/2014/07/08/daily-journal

Front 249

Bufferbloat

Back 249

When routers ship with large incoming buffers to prevent packet loss, thus breaking TCP congestion avoidance algos - Jim Gettys 2010

Hint 249

http://alexmatchneer.com/blog/2014/07/08/daily-journal

Front 250

Refractive index

Back 250

Ratio of speed of light in vacuum to speed in material. ~1.5 in fiber.

Hint 250

http://alexmatchneer.com/blog/2014/07/08/daily-journal

Front 251

World circumference propagation time

Back 251

200 ms

Hint 251

http://alexmatchneer.com/blog/2014/07/08/daily-journal

Front 252

Last mile latency

Back 252

Phenomenon that significant latency is introduced due to neighborhood routers / signal aggregators

Hint 252

http://alexmatchneer.com/blog/2014/07/08/daily-journal