Haile hailelagi

Troubleshooting

Intro

The incident management steps I have in mind when being on-call and getting an alert are:

Verify the issue
Triage
Communicate and scalate if needed
Mitigate

Big-O Time Complexities for Elixir data structures

Map [1]

Operation	Time Complexity
Access	`O(log n)`
Search	`O(log n)`
Insertion	`O(n)` for <= 32 elements, `O(log n)` for > 32 elements [2]
Deletion	`O(n)` for <= 32 elements, `O(log n)` for > 32 elements

https://web.archive.org/web/20110219163448/http://howtohft.wordpress.com/2011/02/15/how-to-build-a-fast-limit-order-book/

The response to my first few posts has been much larger than I’d imagined and I’d like to thank everyone for the encouragement.

If you’re interested in building a trading system I recommend first reading my previous post on general ideas to keep in mind.

My first really technical post will be on how to build a limit order book, probably the single most important component of a trading system. Because the data structure chosen to represent the limit order book will be the primary source of market information for trading models, it is important to make it both absolutely correct and extremely fast.

To give some idea of the data volumes, the Nasdaq TotalView ITCH feed, which is every event in every instrument traded on the Nasdaq, can have data rates of 20+ gigabytes/day with spikes of 3 megabytes/second or more. The individual messages average about 20 bytes each so this means handling

Introduction

The computer driven markets for instruments like stocks and exchange traded stock options, have transformed finance and the flow of capital. These markets are enabled by order matching engines (and the infrastructure that supports this software). Before computer trading networks and matching engines, stocks where traded on cavernous exchange floors and transaction costs where high. When electronic trading fully matured, floor traders were a fading anachronism and transaction costs had been reduced to pennies a share in many cases. Electronic trading could not exist without advanced network infrastructure, but without the software matching engines no shares would change hands. The computer trading networks, the matching engine software has also created a concentrated nexus of potential failure. Failures in these systems have increased as the frequency and volume on the electronic networks has increased. The position of order matching engines in the trading infrastructure makes these systems o

	-- Disable netrw at the very start of your init.lua
	vim.g.loaded_netrw = 1
	vim.g.loaded_netrwPlugin = 1

	-- Set termguicolors to enable highlight groups
	vim.opt.termguicolors = true

	-- Ensure packer is installed
	local fn = vim.fn
	local install_path = fn.stdpath('data')..'/site/pack/packer/start/packer.nvim'

	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

	\documentclass[a4paper,20pt]{article}

	\usepackage{latexsym}
	\usepackage[empty]{fullpage}
	\usepackage{titlesec}
	\usepackage{marvosym}
	\usepackage[usenames,dvipsnames]{color}
	\usepackage{verbatim}
	\usepackage{enumitem}
	\usepackage[pdftex]{hyperref}

	# for ~/.zshrc
	# usage `go-new package_name` binary scaffold OR
	# `go-new package_name --lib` library scaffold

	goScaffold ()
	{
	mkdir -p -- "$1" &&
	cd -P -- "$1" &&
	touch -- "$1.go" &&
	touch -- "$1_test.go"

	# suppress warnings! I know!
	RUSTFLAGS="-Awarnings" cargo test
	RUSTFLAGS="-Awarnings" cargo run

	# OR
	alias "cargo-quick-test"="RUSTFLAGS='-Awarnings' cargo test"
	alias "cargo-quick-run"="RUSTFLAGS='-Awarnings' cargo run"

	https://stackoverflow.com/questions/201323/how-can-i-validate-an-email-address-using-a-regular-expression
	regex = ~r"(?:[a-z0-9!#$%&'+/=?^_`{\|}~-]+(?:\.[a-z0-9!#$%&'+/=?^_`{\|}~-]+)\|\"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]\|\\[\x01-\x09\x0b\x0c\x0e-\x7f])\")@(?:(?:[a-z0-9](?:[a-z0-9-][a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-][a-z0-9])?\|\[(?:(?:(2(5[0-5]\|[0-4][0-9])\|1[0-9][0-9]\|[1-9]?[0-9]))\.){3}(?:(2(5[0-5]\|[0-4][0-9])\|1[0-9][0-9]\|[1-9]?[0-9])\|[a-z0-9-]*[a-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]\|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\])"

	Regex.match(regex, email)