Akihiro Suda AkihiroSuda

3 Concurrent Objects （並行オブジェクト）

この章では並行オブジェクトの correctness と progress を規定する様々な方法を学ぶ。

correctness の3つタイプ

Quiescent consistency
- 弱い制約。ハイパフォーマンスを必要とするシステムに使える
Sequential consistency

You might want to read this to get an introduction to armel vs armhf.

If the below is too much, you can try Ubuntu-ARMv7-Qemu but note it contains non-free blobs.

Running ARM programs under linux (without starting QEMU VM!)

First, cross-compile user programs with GCC-ARM toolchain. Then install qemu-arm-static so that you can run ARM executables directly on linux

内容

Docker Storage Drivers を読んでのメモです。

aufs

p31

With O_WRONLY or O_RDWR - write access look it up in the top branch;

Docker単体でコンテナに固定IPを設定する

pipeworkやweaveを利用せずにコンテナに固定IPを設定するには、docker runで--privilegedオプションを指定し、コンテナ内でIPを設定する方法がある。

$ HOST1=$(docker run --privileged -t -d ubuntu /bin/bash)
$ docker exec $HOST1 ip addr add 192.168.0.10/24 dev eth0

$ HOST2=$(docker run --privileged -t -d ubuntu /bin/bash)
$ docker exec $HOST2 ip addr add 192.168.0.11/24 dev eth0

	#!/bin/bash
	#
	# Add latency to all outgoing traffic on $DEV on tcp/udp $PORT,
	# in the amount of $DELAY.
	#
	# This is matching on both source port and destination port, which
	# may hit you twice if you're accessing a local resource.
	#
	# To see what's currently in effect,
	# tc -s qdisc show dev lo

	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

	#!/usr/bin/env bash

	if [ "$1" == "" ]; then
	echo "usage: $0 <docker_id>"
	echo "Exposes the netns of a docker container to the host"
	exit 1
	fi
	ppid=`docker inspect $1 \| grep Pid \| awk '{print $2 + 0}'`
	if [ "$ppid" == "" ]; then
	echo "lxc parent pid not found"

	#!/usr/bin/env bash

	VERSION="0.0.1"
	set -e
	[ -n "$DEBUG" ] && set -x

	usage() {
	printf "
	Usage: $(basename $0) PROJECT_ID

	#! /usr/bin/env python2.7

	from scapy.all import *
	from netfilterqueue import NetfilterQueue

	def modify(packet):
	pkt = IP(packet.get_payload()) #converts the raw packet to a scapy compatible string

	#modify the packet all you want here

	#include <stdio.h>
	#include <stdlib.h>
	#include <assert.h>
	#include <signal.h>
	#include <errno.h>
	#include <fcntl.h>
	#include <stddef.h>
	#include <sys/syscall.h>
	#include <sys/types.h>
	#include <sys/stat.h>