Akihiro Suda AkihiroSuda

Update, September 2016

OK, you can pretty much ignore what I wrote below this update, because it doesn't really apply anymore.

I wrote this over a year ago, and at the time I had spent a couple of weeks trying to get Kafka 0.8 working with .NET and then Node.js with much frustration and very little success. I was rather angry. It keeps getting linked, though, and just popped up on Hacker News, so here's sort of an update, although I haven't used Kafka at all this year so I don't really have any new information.

In the end, we managed to get things working with a Node.js client, although we continued to have problems, both with our code and with managing a Kafka/Zookeeper cluster generally. What made it worse was that I did not then, and do not now, believe that Kafka was the correct solution for that particular problem at that particular company. What they were trying to achieve could have been done more simply with any number of other messaging systems, with a subscriber reading messages off and writing

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

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;

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

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

	Enable port 8080 through the firewall:
	firewall-cmd --add-port=8080/tcp

	Run socat to make docker sock available via tcp port (note the IP to listen at)
	socat -d -d TCP-LISTEN:8080,fork,bind=192.168.122.214 UNIX:/var/run/docker.sock

	Run pprof on your client:
	go tool pprof http://192.168.122.214:8080/debug/pprof/profile
	Fetching profile from http://192.168.122.214:8080/debug/pprof/profile
	Please wait... (30s)

	#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>

	#! /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

	#!/usr/bin/env bash

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

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

	#!/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"