Yiran Zhou zdyxry

Moved to pidfd-rs

Create system drive

qemu-img create -f qcow2 alpine.qcow2 16G

Install image

Linux

Linux NetFilter, IP Tables and Conntrack Diagrams

IPTABLES TABLES and CHAINS

IPTables has the following 4 built-in tables.

1) Filter Table

Filter is default table for iptables. So, if you don’t define you own table, you’ll be using filter table. Iptables’s filter table has the following built-in chains.

HTTP Streaming (or Chunked vs Store & Forward)

The standard way of understanding the HTTP protocol is via the request reply pattern. Each HTTP transaction consists of a finitely bounded HTTP request and a finitely bounded HTTP response.

However it's also possible for both parts of an HTTP 1.1 transaction to stream their possibly infinitely bounded data. The advantages is that the sender can send data that is beyond the sender's memory limit, and the receiver can act on

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

	// Package gochannels example of how to close a channel written by several goroutines
	package gochannels

	import (
	"math/big"
	"sync"
	)

	// Publisher write sequences of big.Int into a channel
	type Publisher struct {

	---
	apiVersion: extensions/v1beta1
	kind: DaemonSet
	metadata:
	name: oom-killer
	namespace: kube-system
	labels:
	k8s-app: oom-killer
	spec:
	selector:

	from scapy.all import *


	# change this to your test machine's MAC address
	SELF_MAC = '00:0c:29:67:22:c2'

	BCAST_MAC = 'ff:ff:ff:ff:ff:ff'


	# this will send a PROBE ARP request packet to the supplied IP address argument