KlausTrainer

%% @author Yariv Sadan <yarivsblog@gmail.com> [http://yarivsblog.com]
%% @copyright Yariv Sadan 2006-2007
%%
%% @doc  Smerl: Simple Metaprogramming for Erlang
%%
%%  Smerl is an Erlang library
%%  that simplifies the creation and manipulation of Erlang modules in
%%  runtime.
%%
%%  You don't need to know Smerl in order to use ErlyWeb; Smerl

KlausTrainer

ExitPolicy accept *:22        # SSH
ExitPolicy accept *:43        # WHOIS
ExitPolicy accept *:53        # DNS
ExitPolicy accept *:79-81     # finger, HTTP
ExitPolicy accept *:88        # kerberos
ExitPolicy accept *:110       # POP3
ExitPolicy accept *:143       # IMAP
ExitPolicy accept *:194       # IRC
ExitPolicy accept *:220       # IMAP3
ExitPolicy accept *:389       # LDAP

KlausTrainer

#!/bin/bash

if ! [ $1 ];
then
	echo syntax: $0 host [-v]
	exit
fi

if [ "$2" == "-v" ];
then

KlausTrainer

# MySQL Service

description     "MySQL Server"
author          "Mario Limonciello <superm1@ubuntu.com>"

start on (net-device-up
          and local-filesystems
	  and runlevel [2345])
stop on runlevel [016]

KlausTrainer

fun(Head, {Req}) ->

    Fun = fun({Row}, {PrevKey, RowCount}) ->
        Key = case couch_util:get_value(<<"key">>, Row) of
        K when is_list(K) -> hd(K);
        K -> K
        end,
        Doc = couch_util:get_value(<<"value">>, Row),
        DocJson = couch_util:to_binary(couch_util:json_encode(Doc)),
        KeyJson = <<"{\"key\":\"",Key/binary,"\"">>,

KlausTrainer

#!/usr/bin/env ruby

require 'rubygems'
require 'rest_client'
require 'json'
require 'cgi'


def bye
  abort("Usage: #{$0} [log_file(s)] [couch_db_url]\nExample: #{$0} log/* http://admin:secret@127.0.0.1:5984/db")

KlausTrainer

for i in `git fsck --full | grep "dangling commit" | head | grep -o -E "[0-9a-f]+$"`; do git show $i | vim -; done

KlausTrainer

#!/usr/bin/env ruby

require 'rubygems'
require 'rest_client'
require 'json'
require 'cgi'


def bye
  abort("Usage: #{$0} [view_url]\nExample: #{$0} http://admin:secret@127.0.0.1:5984/db/_design/ddoc/_view/recent-posts")

KlausTrainer

#! /bin/sh -e

inotifywait -m -r --exclude "\.swp$" -e modify . | xargs -n 1 -I {} echo "couchapp push" | bash

KlausTrainer

Consistency in BigCouch

In a BigCouch cluster, there are N replicas, who can either be in the state alive or dead. The case of all replicas being alive is defined as the absence of network partitions, i.e., no message is lost. Network partitions are modeled as total failure of one or more replica. For instance, take a set of network partitions P. For each network partition Pi, all replicas that are located in a different network partition than Pi, are defined as dead.

When there's a read or write request, the request first hits one of the replicas, which is referred to as the leader. The leader starts a voting round, i.e., it forwards the request to all replicas. When the leader receives a response from a replica, it's said that the replica has voted. A response may either contain a document version, or some error code indicating e.g. that the document was not found, or the revision number of a newly created document version.

If at least