Daehyung Lee netman2k

A couple of days ago, I had some issues with NFS consistency, not every servers were up to date. Some servers had the good version of the file some hadn’t. However performing a ls -l seemed to fixed tempory the problem after each update (where a simple ls didn’t). Indeed issuing ls with the -l option triggers stat() where ls doesn’t, just because file attributes are called from the stats() function. I needed to investigate…

I. Story

We determined that some web virtual didn’t delivered the same content, some page weren’t updated properly. We quickly figured out that the issue was located of the NFS attribute caching, by default too long, at least in our setup. The first change we made was to enable the noac option on the client mount. However while trying to enhance the consistency of the NFS data, the performance impact was pretty high. The impact was easy to detect and reproduce. Basically everytime a page was request from the webser, the client had to request the NFS server to be sure to del

Generate ssl certificates with Subject Alt Names on OSX

Open ssl.conf in a text editor.

Edit the domain(s) listed under the [alt_names] section so that they match the local domain name you want to use for your project, e.g.

DNS.1   = my-project.dev

Additional FQDNs can be added if required:

Add the following chunk to your existing ISC dhcpd.conf file.

if exists user-class and ( option user-class = "iPXE" ) {
    filename "http://boot.smidsrod.lan/boot.ipxe";
}
else {
    filename "undionly.kpxe";
}

(or see https://gist.github.com/4008017 for a more elaborate setup

	from collections import defaultdict

	import boto3

	"""
	A tool for retrieving basic information from the running EC2 instances.
	"""

	# Connect to EC2
	ec2 = boto3.resource('ec2')

	.vscode/c_cpp_properties.json
	{
	"configurations": [
	{
	"name": "Linux",
	"includePath": [
	"${workspaceFolder}/**"
	],
	"defines": [],
	"compilerPath": "/usr/bin/gcc",

	#!/bin/bash
	# Reference
	# https://github.com/kylemanna/docker-openvpn
	#
	set -o errexit
	OVPN_DATA=/usr/local/etc/openvpn

	# Init OpenVPN server configurations
	# Please refer the URL below to see specific options
	# https://github.com/kylemanna/docker-openvpn/blob/master/bin/ovpn_genconfig

	#!/usr/bin/env python
	# Adapted from Mark Mandel's implementation
	# https://github.com/ansible/ansible/blob/devel/plugins/inventory/vagrant.py
	import argparse
	import json
	import paramiko
	import subprocess
	import sys

	# How to sign your custom RPM package with GPG key

	# Step: 1
	# Generate gpg key pair (public key and private key)
	#
	# You will be prompted with a series of questions about encryption.
	# Simply select the default values presented. You will also be asked
	# to create a Real Name, Email Address and Comment (comment optional).
	#
	# If you get the following response:

	# put this file in /etc/systemd/system/ as root
	# below paths assume solr installed in /opt/solr, SOLR_PID_DIR is /data
	# and that all configuration exists in /etc/default/solr.in.sh which is the case if previously installed as an init.d service
	# change port in pid file if differs
	# note that it is configured to auto restart solr if it fails (Restart=on-faliure) and that's the motivation indeed :)
	# to switch from systemv (init.d) to systemd, do the following after creating this file:
	# sudo systemctl daemon-reload
	# sudo service solr stop # if already running
	# sudo systemctl enable solr
	# systemctl start solr

	#!/usr/bin/env python

	"""
	Display gluster traffic
	This tool uses gluster profiling feature, parsing cumulative statistics.

	To understand correctly the results, you have to divide overall write statistics with number of replicas.
	Also striped volumes needs to be taken in mind - overall statistics just print sum of all bricks
	read/written bytes.