Imran Ansari imranansari

Maintaining a resilient front door at massive scale, from Netflix

Netflix is responsible for about 1/3 of downstream traffic in NA
Responsible team in the company is called "edge engineering"
- Apart from resiliency/scaling, also cares about high velocity product innovation and real time health insights
Basic architecture:
- end-user devices make requests to ELBs, which delegates to zuul, which routes to origin servers serving APIs

Spurred by recent events (https://news.ycombinator.com/item?id=8244700), this is a quick set of jotted-down thoughts about the state of "Semantic" Versioning, and why we should be fighting the good fight against it.

For a long time in the history of software, version numbers indicated the relative progress and change in a given piece of software. A major release (1.x.x) was major, a minor release (x.1.x) was minor, and a patch release was just a small patch. You could evaluate a given piece of software by name + version, and get a feeling for how far away version 2.0.1 was from version 2.8.0.

But Semantic Versioning (henceforth, SemVer), as specified at http://semver.org/, changes this to prioritize a mechanistic understanding of a codebase over a human one. Any "breaking" change to the software must be accompanied with a new major version number. It's alright for robots, but bad for us.

SemVer tries to compress a huge amount of information — the nature of the change, the percentage of users that wil

Neo4j cypher for co-favorited plus additional attribute

Answering an Stackoverflow Question.

I am learning Neo4j and decided to take one of the sample queries and add a twist to it. I took this example http://docs.neo4j.org/chunked/stable/cypher-cookbook-co-favorited-places.html and wanted to say what if there was an additional attribute that you could use to filter the results by. My test I put together was to have tags in the graph as well and then I wanted to search by overlapped favorites desc then by overlapping tags desc.

Here is the sample data I am using:

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

Data Serialization Formats

JSON, MessagePack, and Google's Protocol Buffers are all awesome. Here's how they're awesome on different client environments and how to use them on your rails env.

Some links:

JSON: http://json.org/
MsgPack: http://msgpack.org/
ProtoBufs: https://code.google.com/p/protobuf/

Output from Ruby Client:

The Zen of Cypher

Write functions() in lower case, KEYWORDS in upper.
START each keyword clause
ON a new line.
Use either camelCase or snake_case for node identifiers but be consistent.
Relationship type names should use UPPER_CASE_AND_UNDERSCORES.
Label names should use CamelCaseWithInitialCaps.
MATCH (clauses)-->(should)-->(always)-->(use)-->(parentheses)-->(around)-->(nodes)
Backticks `cân éscape odd-ch@racter$ & keyw0rd$` but should be a code smell.

	BEARER='...'
	def load_tweets(query,since_id=nil,lang="en",page=1,rpp=100)
	res=RestClient.get('https://api.twitter.com/1.1/search/tweets.json',
	{:params=> {:q=>query, :lang=>lang,:count=>rpp,:result_type=>:recent,:since_id=>since_id},
	:accept=>:json,
	:Authorization => "Bearer #{BEARER}"})
	puts "query '#{query}'\n since id #{since_id} result #{res.code}"
	return [] unless res.code==200

	data=JSON.parse(res.to_str)

	extension Array {

	func first() -> Element? {
	if isEmpty {
	return nil
	}
	return self[0]
	}

	func last() -> Element? {

	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8">
	<title>Styled Select</title>
	</head>

	<style>

	* {

	MATCH (n1:node { n.id = "1234" })
	MATCH (n0)-[r1]->(n1)-[r2]->(n2)
	DELETE r1, n1, r2
	MERGE (n0)-[:NEXT]->(n2)