Sh Lin atitan

Scaling your API with rate limiters

The following are examples of the four types rate limiters discussed in the accompanying blog post. In the examples below I've used pseudocode-like Ruby, so if you're unfamiliar with Ruby you should be able to easily translate this approach to other languages. Complete examples in Ruby are also provided later in this gist.

In most cases you'll want all these examples to be classes, but I've used simple functions here to keep the code samples brief.

Request rate limiter

This uses a basic token bucket algorithm and relies on the fact that Redis scripts execute atomically. No other operations can run between fetching the count and writing the new count.

Install StatsD on Debian Stretch

Install nodejs:

# curl -sL https://deb.nodesource.com/setup_12.x | bash -
# apt install -y nodejs

Install build dependencies:

$ sudo apt install git debhelper devscripts dh-systemd

	# Haproxy configuration for SSL request passthrough to different backend based on SNI read from Handshaking stage
	# The Loadbalance will not decode the encrpted data but transparently transfer to the backend server in Private subnet.
	# With such configuration, you can install multiply services with its own SSL certificate in backend in different EC2 instance, but only explosure to public internet with one Loadbalance IP. There is no need to install SSL certificate in Loadbalancer level.

	# Ref:
	# How to support wildcard sni: https://stackoverflow.com/questions/24839318/haproxy-reverse-proxy-sni-wildcard
	# https://www.haproxy.com/blog/enhanced-ssl-load-balancing-with-server-name-indication-sni-tls-extension/
	# https://stuff-things.net/2016/11/30/haproxy-sni/

	update global_variables set
	-- UserDataMonitor
	variable_value="DBMONUSER"
	where variable_name='mysql-monitor_username';

	update global_variables set
	-- PasswordDataMonitor
	variable_value="DBMONPASS"
	where variable_name='mysql-monitor_password';

	# ~/.bundle/config

	---
	BUNDLE_BUILD__MYSQL2: "--with-opt-dir=/usr/local/opt/[email protected]"
	BUNDLE_BUILD__PUMA: "--with-opt-dir=/usr/local/opt/[email protected]"
	BUNDLE_BUILD__THIN: "--with-cflags=-Wno-error=implicit-function-declaration"
	BUNDLE_BUILD__FFI: "--with-cflags=-Wno-error=implicit-function-declaration"
	BUNDLE_BUILD__PG: "--with-cflags=-Wno-error=implicit-function-declaration"
	BUNDLE_JOBS: "8"

Sh Lin atitan

Table of Contents

set -e, -u, -x, -o pipefail

Scaling your API with rate limiters

Request rate limiter

Install StatsD on Debian Stretch

	$ openssl ecparam -name prime256v1 -genkey -noout -out private.ec.key
	$ openssl ec -in private.pem -pubout -out public.pem

	# /usr/local/etc/elasticsearch/jvm.options

	-Xms128m
	-Xmx128m