Bjorn Madsen root-11

High Performance Redis

In response to this brief blog entry, @antirez tweeted for some documentation on high-performance techniques for Redis. What I present here are general high-performance computing (HPC) techniques. The examples are oriented to Redis. but they work well for any program designed to be single- or worker-threaded and asynchronous (e.g. uses epoll).

The motivation for using these techniques is to maximize performance of our system and services. By isolating work, controlling memory, and other tuning, you can achieve significant reduction in latency and increase in throughput.

My perspective comes from the microcosm of my own bare-metal (vs VM), on-premises deployment. It might not be suitable for all scenarios, especially cloud deployments, as I have little experience with HPC there. After some discussion, maybe this can be adapted as [redis.io documentation](https://redis.io/do

	Latency Comparison Numbers (~2012)
	----------------------------------
	L1 cache reference 0.5 ns
	Branch mispredict 5 ns
	L2 cache reference 7 ns 14x L1 cache
	Mutex lock/unlock 25 ns
	Main memory reference 100 ns 20x L2 cache, 200x L1 cache
	Compress 1K bytes with Zippy 3,000 ns 3 us
	Send 1K bytes over 1 Gbps network 10,000 ns 10 us
	Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD

	from tqdm import tqdm
	import requests

	# file url
	url = 'https://dumps.wikimedia.org/enwiki/latest/enwiki-latest-stub-meta-history.xml.gz' #file size is '70.5GB'
	# stream true is required
	response = requests.get(url, stream=True)
	# total file size
	t = int(response.headers.get('content-length', 0))
	block_size = 1024**2 #1 Mbit

	import time
	import requests
	import zlib
	# pip install lz4 pylzma
	import lz4
	import pylzma as lzma


	def analysis_ratios(source):
	time_before_zip = time.time()

	If 2fa is enabled on github switch to ssh instead of https on linux

	1. generate an ssh keypair on your linux box
	ssh-keygen -t {rsa\|dsa}

	2. add the public key to github: profile - settings - ssh keys

	3. switch from https to ssh

	Check your repo remote: