mtsuszycki

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GENERAL INFO

Linux Virtual Server (LVS) is a high availability Layer4 load balancer that transparently for the users presents cluster
of real servers as one virtual server.  
Internal cluster architecture is hidden and only IP of virtual server (VIP) is available to the outside world.  
In general LVS is used to load balance TCP and UDP protocols and doesn't care what machines and operating systems are used 
as real servers. 
Properly configured LVS system is able to handle several virtual servers with dozens of real servers in a cluster, 

mtsuszycki

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mtsuszycki

#!/bin/bash

# script to check ElasticSearch indexes' size and compare to their average.
# send an email if current index size is lower or grater than average +20%
# averages are in the config file, for example:
#
#declare -A index
#index[logcdn]=25000000
#index[logjboss]=950000
#index[logmonitor]=12000

mtsuszycki

#!/bin/bash

# example of removing by query from elasticsearch
# redirect the output to a file and then use curl to bulk load it to ES:
# es_remove_selected_rows.sh > out.json
# 
# curl --max-time 120000 -XPOST "$es_host:9200/_bulk" --data-binary @out.json
#
# change conditions in the query/term below

mtsuszycki

#!/bin/bash 

function emsg() { email_body="$email_body\n${1}"; }


function email()
{
        local subject=$1 rcpt=$2
        echo -e "$email_body\n\n\n" | mail -s "$subject" -r [email protected] "$rcpt"
}

mtsuszycki

# Basic command to manage VMs

# list all defined domains (VMs) and their status (running, shut off etc.)
virsh list --all

# stop VM (named _myvm_) gracefully
virsh shutdown _myvm_

# start VM

mtsuszycki

#!/usr/bin/ruby

# examples
# ./htmlgrep.rb "input#gbv"  "http://www.google.co.uk"
# ./htmlgrep.rb "div#gbv"  "http://www.google.co.uk"
# htmlgrep.rb "[@class='gbm']"  "http://www.google.co.uk"
# ./htmlgrep.rb "[@class='gbmc']/ol/li"  "http://www.google.co.uk"
# ~/htmlgrep.rb '.postblockcat_whitesquare/a' HERE\ -\ Nokia\ Conversations.html | grep -Eo '<a href[^>]+'   |  sed 's/title=/,/
# g; s/<a href=//g;' > HERE\ -\ Nokia\ Conversations.csv

mtsuszycki

# execute remote command via ssh passwordlessly (no ssh keys) on many hosts
export SSHPASS=my_password  # sshpass will use it

printf "host1\host2\n" | xargs -i sshpass -e ssh your_username@{} 'ls -la'
# or
cat hostlist.txt | xargs -i sshpass -e ssh your_username@{} 'ls -la'

# mass copy ssh public key onto many hosts 
cat hostlist.txt | xargs sshpass -e ssh-copy-id -i ~/.ssh/id_rsa.pub

mtsuszycki

#!/usr/bin/ruby

require 'rubygems'
require 'mechanize'

# to avoid 'ran out of buffer space on element' error
module WWW
  require 'hpricot'
  class Mechanize
    Hpricot.buffer_size = 262144  # added by naofumi