Jonathan Rose Dunlap jadbox

Creating a redis Module in 15 lines of code!

A quick guide to write a very very simple "ECHO" style module to redis and load it. It's not really useful of course, but the idea is to illustrate how little boilerplate it takes.

Step 1: open your favorite editor and write/paste the following code in a file called module.c

#include "redismodule.h"
/* ECHO <string> - Echo back a string sent from the client */
int EchoCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {

HTTP Server Micro-Benchmarks

Here are the results of testing returning a small text string from a HTTP request implemented in various languages all, tested under the same conditions. The command used to test the server implementations was:

wrk -c 40 -d 60s -t 2 --latency http://localhost:3000

Python3

This test used the new async support in python 3.5.

#System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

##Basic Steps

Clarify and agree on the scope of the system

User cases (description of sequences of events that, taken together, lead to a system doing something useful)
- Who is going to use it?
- How are they going to use it?

Comprehensions in Python the Jedi way

by Bjørn Friese

Beautiful is better than ugly. Explicit is better than implicit.

-- The Zen of Python

I frequently deal with collections of things in the programs I write. Collections of droids, jedis, planets, lightsabers, starfighters, etc. When programming in Python, these collections of things are usually represented as lists, sets and dictionaries. Oftentimes, what I want to do with collections is to transform them in various ways. Comprehensions is a powerful syntax for doing just that. I use them extensively, and it's one of the things that keep me coming back to Python. Let me show you a few examples of the incredible usefulness of comprehensions.

	# Makefile for transpiling with Babel in a Node app, or in a client- or
	# server-side shared library.

	.PHONY: all clean

	# Install `babel-cli` in a project to get the transpiler.
	babel := node_modules/.bin/babel

	# Identify modules to be transpiled by recursively searching the `src/`
	# directory.

	#------------------------------------------------------------------------------
	# AUTOVACUUM PARAMETERS
	#------------------------------------------------------------------------------

	#autovacuum = on # Enable autovacuum subprocess? 'on'
	# requires track_counts to also be on.
	log_autovacuum_min_duration = 0 # -1 disables, 0 logs all actions and
	# their durations, > 0 logs only
	# actions running at least this number
	# of milliseconds.

	package io.github.timothyrenner.kstreamex.tablejoin;

	import org.apache.kafka.clients.producer.KafkaProducer;
	import org.apache.kafka.clients.producer.ProducerRecord;

	import org.apache.kafka.common.serialization.Serdes;
	import org.apache.kafka.streams.KafkaStreams;
	import org.apache.kafka.streams.KeyValue;
	import org.apache.kafka.streams.StreamsConfig;
	import org.apache.kafka.streams.kstream.KStream;

	import {Stream} from 'most'

	const fromNodeCallBack = fn => (...args) => new Stream(new CallBackSource(fn, args))

	class CallBackSource {
	constructor (fn, args) {
	this.fn = fn
	this.args = args
	}

	import {Stream} from 'most'

	const fromNodeCallBack = fn => (...args) => new Stream(new CallBackSource(fn, args))

	class CallBackSource {
	constructor (fn, args) {
	this.fn = fn
	this.args = args
	}