Linux perf tools

http://www.brendangregg.com/Perf/linuxperftools.png

Nginx as CDN

user www-data;
worker_processes 4;

error_log  /var/log/nginx/error.log;
pid        /var/run/nginx.pid;

events {
    worker_connections  1024;
    # multi_accept on;
}

http {
        server_names_hash_bucket_size 64;
        include       /etc/nginx/mime.types;

        access_log      /var/log/nginx/access.log;

    sendfile        on;
    #tcp_nopush     on;

    #keepalive_timeout  0;
    keepalive_timeout  65;
    tcp_nodelay        on;

    include /etc/nginx/conf.d/*.conf;
    include /etc/nginx/sites-enabled/*;

#### firstApp and secondApp Caching
    proxy_cache_path    /var/www/cache/firstApp levels=1:2 keys_zone=firstApp_cache:30m max_size=500m inactive=600m;
    # secondApp Caching
    proxy_cache_path    /var/www/cache/secondApp levels=1:2 keys_zone=secondApp_cache:30m max_size=500m inactive=600m;

    proxy_temp_path     /var/www/cache/tmp;
    # secondApp app CDN
    server {
        listen 5002;
        ssl on;
        ssl_certificate /etc/nginx/vmh02-cdn01-p91.myDomain.net.crt;
        ssl_certificate_key /etc/nginx/vmh02-cdn01-p91.myDomain.net.key;

        #listen       443;
        server_name  vmh02-cdn01-p91.myDomain.net;
        location / {
            proxy_pass https://AppUrlforSecondApp.mysecondappURL.net/;  #// this should point to secondApp server secondApp -
            proxy_cache secondApp_cache;
            proxy_cache_valid 200 302 60m;
            proxy_cache_valid 404 1m;
            #root   html;
            #index  index.html index.htm;
        }
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
    }
### app CDN
    server {
        listen  5008;
        ssl on;
        ssl_certificate /etc/nginx/vmh02-cdn01-p91.myDomain.net.crt;
        ssl_certificate_key /etc/nginx/vmh02-cdn01-p91.myDomain.net.key;
        server_name  vmh02-cdn01-p91.myDomain.net;
        location / {
            proxy_pass https://secondAppLInk-stage.AppSitelinkHere.net/;  #// this should be the firstApp IP address or LB
            proxy_cache firstApp_cache;
            proxy_cache_valid 200 302 60m;
            proxy_cache_valid 404 1m;
        }
   }
}

netstat

To display open ports, enter:

netstat --listen

To display open ports and established TCP connections on a Linux host, enter:

netstat -vatn

Run these on the hosts that stop responding.

Additionally, you can use strace to trace system calls and signals. Specify the "-e trace=network" trace the network-related system calls. As an example, you can run the following command to trace the network signals for the ping -c 3 10.0.0.1command and output to a file called "ping.trace".

strace -e trace=network -o ping.trace ping -c 3 10.0.0.1

$ nc -z -v mystite.com 80

Connection to mystite.com 80 port [tcp/http] succeeded!

$ curl -I mystite.com

HTTP/1.1 404 Not Found Content-length: 169 Content-Type: text/html Date: Thu, 12 Jun 2014 23:42:23 GMT Server: nginx/1.1.19 Connection: keep-alive

One Docker Way

Docker way

Tools Needed:

Packer: Building the images : http://www.packer.io/

Docker: Managing Containder : https://www.docker.io/

Salt: Managing the automated configuration : http://www.saltstack.com/

Packer create identical machine images from a single source configuration. It is easy to maintain.Use packer to build Docker images.

Docker:

• Is like git for filesystems (Docker pull/push/commit)
• Is like Vagrant for LXC containers (docker run / Vagrant up,docker kill / vagrant halt, docker rm/vagrant destroy, Docker file / Vagrantfile)
• It has its own proces space
• It has its own network interface

Containers:

• Containers are isolated, but share OS , bin/libraries
• Containers are process and not VMs, thats why they are so fast
• faster restart
• less overhead
• Copy on write allow to save only deltas

Install Teamcity 8.1 on Ubuntu 12.04

Download teamcity

wget -c http://www.jetbrains.com/teamcity/download/ 

Create dedicated team city user:

adduser --system --shell /bin/bash --gecos 'TeamCity Build Control' --group --disabled-password --home /opt/teamcity teamcity

Install Java

apt-get -y install software-properties-common
apt-add-repository ppa:webupd8team/java
apt-get -y update
echo debconf shared/accepted-oracle-license-v1-1 select true | debconf-set-selections
echo debconf shared/accepted-oracle-license-v1-1 seen true | debconf-set-selections
DEBIAN_FRONTEND=noninteractive apt-get -y install oracle-java7-installer

Install mysql

apt-get install mysql-server

Create database & user

mysql>create user tcclient;
mysql>create database teamcity default charset utf8;
mysql>create user tcclient;
mysql>grant all privileges on teamcity.* to tcclient@localhost identified by 'secure_password';

Download MySQL JDBC driver from oracle site and copy it to /opt/teamcity/data/.BuildServer/lib/jdbc

Create Teamcity server start script in init.d

vim /etc/init.d/teamcity-server

#!/bin/bash
# /etc/init.d/teamcity - startup script for teamcity
export TEAMCITY_DATA_PATH="/opt/teamcity/data/.BuildServer"

case $1 in
start)
start-stop-daemon --start -c teamcity --exec /opt/teamcity/TeamCity/bin/teamcity-server.sh start
;;

stop)
start-stop-daemon --stop -c teamcity --exec /opt/teamcity/TeamCity/bin/teamcity-server.sh stop
;;

esac

exit 0

Make sure all the team city files and directory are owned by team city user

cd /opt
chown -R teamcity.teamcity teamcity

Download MySQL JDBC driver from oracle site and copy it to /opt/teamcity/data/.BuildServer/lib/jdbc

Open the Teamcity URL in the browser:

http://teamcity:8111/mnt

Nginx Proxy for Teamcity

apt-get install nginx

Create a file team city under#

cd /etc/nginx/sites-available/

vim teamcity

server {
 listen 80;
 server_name teamcity;

 location / {
            proxy_pass http://localhost:8111;
    }
}

Check for the syntax

nginx -t -c /etc/nginx/sites-available/default

ln -s /etc/nginx/sites-available/teamcity teamcity

service nginx restart

Now you can access the machine as

http://teamcity/

JIRA upgrade from Ver. 5.2 to 6.2

JIRA upgrade from Ver. 5.2 to 6.2

Steps:

Take jira backup in xml format- Login to JIRA with admin privileges and export the backup

• Copy data folder from JIRA - Attachments /Gravatar/logos
• Copy plugins
• Stop JIRA - /etc/init.d/JIRA stop
• Download the latest jira .bin from Atlassian JIRA download page.

chmod a+x atlassian-jira-X.Y.bin
mkdir -p /opt/atlassian/jira/

• Execute the '.bin' file to start the upgrade wizard.
• choose #2

/opt/atlassian/jira/

Install data directory

/opt/jira6/

• Create mysql database:

mysql> CREATE DATABASE jiradb6 CHARACTER SET utf8 COLLATE utf8_bin;
mysql> GRANT SELECT,INSERT,UPDATE,DELETE,CREATE,DROP,ALTER,INDEX on jiradb6.* TO 'jirauser'@'localhost' IDENTIFIED BY 'jira_secure_passwd';Query OK, 0 rows affected (0.05 sec)
mysql> flush privileges;

• Download mysql-connector from oracle website and copy it to the JIRA/lib directory.

scp mysql-connector-java-5.1.30-bin.jar /opt/atlassian/jira/lib/

• During the https:// browse give the absolute location of DB xml locaiton : the setup wizard will import all the db.
• Copy the attachments,gravatar & logos from old installation to the new. i.e #scp -r attachments/ /opt/jira6/data/
• Make sure all the permission give to jira user and jira group if you are installing on the same machine then the new user will be jira1 instead of jira

Check the logs. ie. tail -f /opt/atlassian/jira/logs/catalina.2014-04-01.log

Systems

Load - 1
Uptime

10:24  up 6 days, 14:52, 4 users, load averages: 1.74 2.07 2.09
1-5-15 minute load average
System load: avg no. of processes in a runnable or uninterruptible state.
Runnable: Waiting for CPU
Uninterruptible: waiting for I/O

1 CPU with  1 Load means : full utilization/ full load
1 CPU with  load 2 : Twice the load that system  can handle

Check what kind of load system is under:
CPU
RAM
I/O
Network

As system that is out of memory can be due to I/O load because the system starts swapping and start using the swap space

Top

Helpful in identifying what resource you are running out of system resources, once zeroed down to that then you can try to find out which what process are consuming those  resources.

top - 13:35:06 up 227 days, 19:01,  1 user,  load average: 0.00, 0.01, 0.05
Tasks: 124 total,   1 running, 123 sleeping,   0 stopped,   0 zombie
Cpu(s):  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:   8167620k total,  5987132k used,  2180488k free,   187984k buffers
Swap:   498684k total,        8k used,   498676k free,  5428964k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
    1 root      20   0 24332 1956 1036 S    0  0.0   0:08.08 init
    2 root      20   0     0    0    0 S    0  0.0   0:00.42 kthreadd
    3 root      20   0     0    0    0 S    0  0.0  16:48.59 ksoftirqd/0
    6 root      RT   0     0    0    0 S    0  0.0   0:33.68 migration/0
    7 root      RT   0     0    0    0 S    0  0.0   0:47.78 watchdog/0

PID: Process ID- unique number assigned to every process on a system

top -b -n 1 | tee output

 wa: I/O wait

This number represents the percentage of CPU time that is spent waiting for I/O. It is a particularly valuable metric when you are tracking down the cause of a sluggish system, because if this value is low, you can pretty safely rule out disk or network I/O as the cause

id: CPU idle time 

This is one of the metrics that you want to be high. It represents the percentage of CPU time that is spent idle. If you have a sluggish system but this number is high, you know the cause isn’t high CPU load.

 st: steal time

If you are running virtual machines, this metric will tell you the percentage of CPU time that was stolen from you for other tasks.

dig

for i in `whois mydomain.com | grep '^Name Server' | awk '{print $NF}'`; do dig @$i www.mydomain; done

Cassandra

* Structured data
* Fast write
* Distributed - Can run of more than 2 nodes
* Column oriented database not like mysql(row oriented database)
* Good for very high volume of data

DynamoDB(amazon was) and HBase are also  column base data store.

- Consistency
- Availability
- Partition Tolerance

Install on ubuntu 12.04

http://www.datastax.com/download

Download and untar.

Data Collection @Heka Way

Tool for high performance data gathering, analysis, monitoring, and reporting.

Heka’s main component is hekad, a lightweight daemon program that can run on nearly any host machine which does the following: Gathers data through reading and parsing log files, monitoring server health, and/or accepting client network connections using any of a wide variety of protocols (syslog, statsd, http, heka, etc.).

Heka is written in Go, Pretty fast.

Inspired by log stash

apps/logs/sytems ==> Heka==> ES/Logfile

Input: Read in

Decoder: Decode info into a message instance

Filters: Parse, process,

Output: send out data, write out to logs, forward to heka.

Plugin: Go or Lua

Checking the logs by tail -f /var/log/* is very time consuming task specially when you have to troubleshoot a tons of logs. Better make a graph from that data and do analysis on top of that.

Heka is one of the latest tool that can help in logs collection and analysis. But you need some other tool as well to get some meaningful data. Heka alone is not enough.It is just a data collection tool.

You can use: Elastic Search, Kibana, Heka to build a complete logs analysis tool.

Install Heka on:

OS: Ubuntu 12.04

Site: https://github.com/mozilla-services/heka/releases

Install the compatible binary:

root@vmhost18:~# wget -c https://github.com/mozilla-services/heka/releases/download/v0.5.0/heka_0.5.0_amd64.deb

root@vmhost18:~# dpkg -i heka_0.5.0_amd64.deb

Create a hekad.toml configuration file in /etc/

root@vmhost18:~# vim /etc/hekad.toml

[LogfileInput]
 logfile = "/var/log/auth.log"
 decoder = "syslog_decoder"
[syslog_decoder]
 type = "PayloadRegexDecoder"
 match_regex = '^(?P\w+\s+\d+ \d+:\d+:\d+) (?P\S+) (?P\w+)\[?(?P\d+)?\]?:'
 timestamp_layout= 'Jan _2 15:04:05'
[syslog_decoder.message_fields]
 Type = "SyslogLog"
 Host = "%Host%"
 Program = "%Program%"
 PID = "%PID%"
[LogOutput]
 message_matcher = "TRUE"
[ElasticSearchOutput]
 message_matcher = "Type == 'SyslogLog'"

Now point the hekad to the configuration file.

root@vmhost18:~# hekad -config=/etc/hekad.toml | more
2014/03/10 21:05:57 Loading: [LogfileInput]
2014/03/10 21:05:57 Loading: [syslog_decoder]
2014/03/10 21:05:57 Loading: [LogOutput]
2014/03/10 21:05:57 Loading: [ElasticSearchOutput]
2014/03/10 21:05:57 Loading: [ProtobufDecoder]
2014/03/10 21:05:57 Starting hekad...
2014/03/10 21:05:57 Output started:  LogOutput
2014/03/10 21:05:57 Output started:  ElasticSearchOutput
2014/03/10 21:05:57 MessageRouter started.
2014/03/10 21:05:57 Input started: LogfileInput
2014/03/10 21:05:57 Input 'LogfileInput': Line matches, continuing from byte pos: 95266

Now download and Install elasticserarch

http://www.elasticsearch.org/download/

For ubuntu 12.04 download the .deb and install the same way as we did with Heka.

root@vmhost18:~# wget -c https://download.elasticsearch.org/elasticsearch/elasticsearch/elasticsearch-1.0.1.deb

You need to install java runtime first.

root@tc:~# apt-get install java7-runtime-headless

Reading package lists... Done Building dependency tree Reading state information... Done Note, selecting 'openjdk-7-jre-headless' instead of 'java7-runtime-headless'

root@vmhost18:~# dpkg -i elasticsearch-1.0.1.deb

Selecting previously unselected package elasticsearch. (Reading database ... 70512 files and directories currently installed.) Unpacking elasticsearch (from elasticsearch-1.0.1.deb) ... Setting up elasticsearch (1.0.1) ... Adding system user elasticsearch' (UID 110) ... Adding new userelasticsearch' (UID 110) with groupelasticsearch' ... Not creating home directory/usr/share/elasticsearch'.

NOT starting elasticsearch by default on bootup, please execute

sudo update-rc.d elasticsearch defaults 95 10

In order to start elasticsearch, execute

sudo /etc/init.d/elasticsearch start

Processing triggers for ureadahead ...

root@vmhost18:~# /etc/init.d/elasticsearch start
 * Starting Elasticsearch Server

Now install Kibana as well:

http://www.elasticsearch.org/overview/kibana/installation/


root@vmhost18:~# sudo apt-get install nginx

After this operation, 2,350 kB of additional disk space will be used. Do you want to continue [Y/n]?

root@vmhost18:~# sudo service nginx start
Starting nginx: nginx.

root@vmhost18:~# wget -c https://download.elasticsearch.org/kibana/kibana/kibana-3.0.0milestone5.tar.gz

$ tar xvzf kibana-3.0.0milestone5.tar.gz

$root@vmhost18:~#  sudo mv kibana-3.0.0milestone5 /usr/share/nginx/www/kibana

http://vmost18/

You can:

Use the multiple output plug-ins of Heka to write the files out to disk for longer retention (text compresses really nicely, and takes up a lot less space than the Elasticsearch data). Split the components up, and build clusters for each piece: an Elasticsearch cluster, a RabbitMQ cluster, an rsyslog host for long file retention, a Heka cluster — with nodes doing different types of message processing;

Other popular Open source routing systems: - Graylog2 (Supports only read/write from a single index), but other release will be supporting multiple index - LogStash

Both of these have builtin elastic search implementations.

Logstash and elastic search are disk and memory intensive as all other java applications are. You don't want to go past 32 GB of RAM dedicated to ElasticSearch and reserve atleast 8 GB to the OS for file-system caching.

Start with 3 servers in your ElasticSearch cluster. This gives you the flexibility to shutdown a server and maintain full use of your cluster.

/etc/security/limits.conf'

 # Ensure ElasticSearch can open files and lock memory!
elasticsearch   soft    nofile          65536
elasticsearch   hard    nofile          65536
elasticsearch   -       memlock         unlimited

You should also configure ElasticSearch's minimum and maximum pool of memory be set to the same value. This takes care of all the memory allocation at startup, so you don't have threads waiting to get more memory from the kernel

ngrep & tcpdump

ngrep -q -d eth0 -W byline host my domain.com and port 80

tcpdump -s 1111  port 80 -w capture_file

tcpdump -nnvvS and src 10.5.2.3 and dst port 3389


# Traffic originating from Mars or Pluto that isn't to the SSH port

tcpdump -vv src mars and not dst port 22


Monitor network traffic / Find the rouge IP address  machine

tcpdump -l -n arp | egrep 'arp who-has' | head -100 | awk '{ print $NF }' |sort | uniq -c | sort -n

Vagrant + Puppet + RVM + serverspec

http://serverspec.org/
http://rvm.io/
http://docs.puppetlabs.com/learning/
http://mouapp.com/



What we want to achieve:
Install hypervisor for ubuntu-12.04

Install vagrant
Install virtual box
Create a directory on the system for this project, say KVM
mkdir kvm

Create a Gemfile
vim Gemfile
source 'https://rubygems.org'

gem 'colorize'
gem 'facter', "1.6.5"
gem 'puppet', "2.7.20"
gem 'serverspec'
gem 'puppet-lint'
gem 'fpm'

Create a Rakefile
 vim Rakefile

require 'rake'
require 'rspec/core/rake_task'

RSpec::Core::RakeTask.new(:spec) do |t|
  t.pattern = 'spec/*/*_spec.rb'
end

Create/initialize a vagrant file : vagrant init
 config.vm.box = "precise64"
config.vm.box_url = "http://files.vagrantup.com/precise64.box"
config.vm.network :private_network, ip: "192.168.33.10"
config.vm.provision :shell, inline: "apt-get update -y"

   config.vm.provision :puppet do |puppet|
     puppet.module_path = "modules"
     puppet.manifests_path = "manifests"
     puppet.manifest_file  = "site.pp"
   end


Make two directories as
manifests/site.pp
modules/kvm/manifests/init.pp

Mainfests is plays the role of "what to be done" and Modules plays the role of "how to be done"


Vim init.pp
class l3-kvm {

  package {
     "kvm-ipxe":
         ensure => present;
     "python-vm-builder":
        ensure => present;
      "ubuntu-virt-server":
         ensure => present;
  }

}


====
vim site.pp

### Global variables ###

#backup settings
File { backup => local }
# Default path
Exec { path => [ "/usr/local/sbin/", "/bin/", "/sbin/" , "/usr/bin/", "/usr/sbin/" ] }

# Centralized backup filebucket
filebucket { local: path => "/var/lib/puppet/clientbucket" }

node /precise64/ {
  include kvm
}


 rake -T
(in /Users/n/work/techops/kvm)
rake spec  # Run RSpec code examples


==

-->

user [kvm] $ ls -la
total 80
drwxr-xr-x  18 user  staff   612 Jan 10 21:10 .
drwxr-xr-x  55 user  staff  1870 Jan 10 15:47 ..
drwxr-xr-x   3 user  staff   102 Jan 10 16:10 .bundle
-rw-r--r--   1 user  staff   151 Jan 10 15:59 .gemrc
drwxr-xr-x  13 user  staff   442 Jan 10 17:15 .git
-rw-r--r--   1 user  staff    59 Jan 10 16:00 .gitignore
-rw-r--r--   1 user  staff    30 Jan 10 16:00 .rspec
-rw-r--r--   1 user  staff     7 Jan 10 16:00 .ruby-gemset
-rw-r--r--   1 user  staff    16 Jan 10 16:00 .ruby-version
drwxr-xr-x   3 user  staff   102 Jan 10 15:40 .vagrant
-rw-r--r--   1 user  staff   136 Jan 10 15:49 Gemfile
-rw-r--r--   1 user  staff  1213 Jan 10 16:10 Gemfile.lock
-rw-r--r--@  1 user  staff   353 Jan 10 17:12 README.md
-rw-r--r--   1 user  staff   124 Jan 10 16:17 Rakefile
-rw-r--r--   1 user  staff  3413 Jan 10 17:06 Vagrantfile
drwxr-xr-x   3 user  staff   102 Jan 10 16:58 manifests
drwxr-xr-x   3 user  staff   102 Jan 10 16:57 modules
drwxr-xr-x   4 user  staff   136 Jan 10 16:17 spec

====

more .gemrc
:backtrace: false
:benchmark: false
:bulk_threshold: 1000
:sources:
- http://rubygems.org/
:update_sources: true
:verbose: true
gem: --no-ri --no-rdoc
==
more .gitignore
.vagrant
.DS_Store
scripts/build
*.box
.bundle
*.swp
*.swo

====
 more .rspec
--colour
-f
progress
-f
doc
==
more .ruby-gemset
puppet
==

more .ruby-version
ruby-1.9.2-p290


==

vim kvm/spec/default

require 'spec_helper'

describe package('ubuntu-virt-server') do
  it { should be_installed }
end

describe package('python-vm-builder') do
  it { should be_installed   }
end

describe package('kvm-ipxe') do
  it { should be_installed }
end

#describe file('/etc/httpd/conf/httpd.conf') do
 # it { should be_file }
#  it { should contain "ServerName default" }
#end

==
puppet apply --verbose --debug --modulepath modules manifests/site.pp

Empty /tmp directory in linux

11 10 * * * /usr/bin/find /tmp/ -maxdepth 2 -name "*" -not -name tmp -exec rm -rf {} \; > /dev/null 2>&1

Cleanup /tmp directory automatically every day

sed -i 's/0/1/' /etc/default/rcS

Customized zabbix monitoring

# Customized disk i/o monitoring
UserParameter=custom.vfs.dev.read.ops[*],cat /proc/diskstats | grep $1 | head -1 | awk '{print $$4}'
UserParameter=custom.vfs.dev.read.ms[*],cat /proc/diskstats | grep $1 | head -1 | awk '{print $$7}'
UserParameter=custom.vfs.dev.write.ops[*],cat /proc/diskstats | grep $1 | head -1 | awk '{print $$8}'
UserParameter=custom.vfs.dev.write.ms[*],cat /proc/diskstats | grep $1 | head -1 | awk '{print $$11}'
UserParameter=custom.vfs.dev.io.active[*],cat /proc/diskstats | grep $1 | head -1 | awk '{print $$12}'
UserParameter=custom.vfs.dev.io.ms[*],cat /proc/diskstats | grep $1 | head -1 | awk '{print $$13}'
UserParameter=custom.vfs.dev.read.sectors[*],cat /proc/diskstats | grep $1 | head -1 | awk '{print $$6}'
UserParameter=custom.vfs.dev.write.sectors[*],cat /proc/diskstats | grep $1 | head -1 | awk '{print $$10}'

# Customized MySQL monitoring
UserParameter=mysql.daily,php /etc/zabbix/scripts/mysql.php live zabbix xxxxxxxxx
UserParameter=mysql.live,php /etc/zabbix/scripts/mysql.php live zabbix   xxxxxxxx

# Pacemaker monitoring
UserParameter=pacemaker.status, sudo /usr/sbin/crm_mon -s |cut -f2 -d:
UserParameter=pacemaker-ipresource.status, sudo /usr/sbin/crm_mon -1 |grep "heartbeat:IPaddr2" |awk '{print $3}'
UserParameter=pacemaker-iparpresource.status, sudo /usr/sbin/crm_mon -1 |grep "heartbeat:SendArp" |awk '{print $3}'

UserParameter=pacemaker-vip.master, sudo /usr/sbin/crm_mon -1 |grep "heartbeat:IPaddr2" |awk '{print $4}'
UserParameter=pacemaker-arp.master, sudo /usr/sbin/crm_mon -1 |grep "heartbeat:SendArp" |awk '{print $4}'

UserParameter=pacemaker.ha.failchk, /usr/bin/sudo /usr/sbin/crm_mon -1| /bin/egrep -i 'Failed actions'
UserParameter=pacemaker.ha.onlinechk, /usr/bin/sudo /usr/sbin/crm_mon -1| /bin/egrep -i 'offline'
UserParameter=pacemaker.ha.cleanchk, /usr/bin/sudo /usr/sbin/crm_mon -1| /bin/egrep -i 'UNCLEAN'

UserParameter=redis_stats[*],/etc/zabbix/scripts/redis.pl $1 $2 $3

Website monitoring

# mysite monitoring
UserParameter=mysite.check,wget --no-check-certificate -O- https://mysite.com/login

Local health check

#  monitoring
UserParameter=app.myadmin.health, /usr/bin/w3m -dump -no-cookie http://localhost:8080/health | sed 's///g' | grep -wc 'appStatus=\"1\"'


Mongo Monitoring

UserParameter=mongo.uptime, /etc/zabbix/scripts/mongo_plugin.py serverStatus uptime
UserParameter=mongo.current.connections, /etc/zabbix/scripts/mongo_plugin.py serverStatus connections current
UserParameter=mongo.available.connections, /etc/zabbix/scripts/mongo_plugin.py serverStatus connections available


# Custom LDAP monitoring
UserParameter=ldap.search.status, /usr/bin/ldapsearch -x -b '' -s base '(objectclass=*)' namingContexts | grep -wc "Success"


Mysql-Slave monitoring

# MySQL Slave Process monitoring

# MySQL Slave Process monitoring
UserParameter=mysql.ha.Slave_IO_Running, /usr/bin/mysql -h "localhost" -u "zabbix" -p"xxxxxxx" "mysql" -se  "show slave status\G" | grep Slave_IO_Running | awk '{print $2}'
UserParameter=mysql.ha.Last_SQL_Errno, /usr/bin/mysql -h "localhost" -u "zabbix" -p"xxxxxxx" "mysql" -se  "show slave status\G" | grep Last_SQL_Errno | awk '{print $2}'
UserParameter=mysql.ha.Seconds_Behind_Master, /usr/bin/mysql -h "localhost" -u "zabbix" -p"xxxxxxx" "mysql" -se  "show slave status\G" | grep Seconds_Behind_Master | awk '{print $2}'
UserParameter=mysql.ha.Slave_SQL_Running, /usr/bin/mysql -h "localhost" -u "zabbix" -p"xxxxxxx" "mysql" -se  "show slave status\G" | grep Slave_SQL_Running | awk '{print $2}'
UserParameter=mysql.ha.Last_Errno, /usr/bin/mysql -h "localhost" -u "zabbix" -p"xxxxxxx" "mysql" -se  "show slave status\G" | grep Last_Errno | awk '{print $2}'
UserParameter=mysql.ha.Last_IO_Errno, /usr/bin/mysql -h "localhost" -u "zabbix" -p"xxxxx" "mysql" -se  "show slave status\G" | grep Last_IO_Errno | awk '{print $2}'


#monitor SSL cert

UserParameter=cert_check[*],/etc/zabbix/externalscripts/ssl_check.sh $1

(You have to create a template in zabbix based on this )

cannot find device br0 failed to bring up br0

Make sure you have bridge-utils package installed.

apt-get install bridge-utils

Import a VM in KVM

Virt-Install

virt-install --name vmhost9-vm01 --ram 8192 --vcpus=4 --disk path=/var/lib/libvirt/images/vmhost9-vm01.img,size=20 -v --accelerate --os-type=linux --keymap=en-us --network=bridge:br0 --import

tcpdump for X-Forwarded-For header

How to take tcp dump for a service that is running on port 4002

#tcpdump -vvvs 1024 -l -A -w /tmp/web-1.pcap tcp port 4002

or

Take a dump to some specific network interface on some specific port.

tcpdump -i eth0.12 -s0 -w /tmp/web-1.pcap port 4002

How to read the tcpdump

tcpdump -X -vv -r web-1.pcap

or

use wireshark

Mysql dump and restore it on remote machine

SourceHost

#mysqldump --opt --skip-lock-tables -umyuser -pmy-secret-password teamcity --extended-insert --routines --add-drop-table | mysql -ubackup -pbackup -hremotehost.myodmain.com teamcity

If you want to reset the root password

mysql --defaults-file=/etc/mysql/debian.cnf

update mysql.user set password=PASSWORD('password') where user='root';

mount

# df

# cat /etc/fstab

# mount -a

# umount -a

sudo fdisk -l

Find the newly added hard disk,

To create the partition on the second Hard drive,

sudo fdisk /dev/sdx

u

n

p

w

Now we need to format our newly created partition using the following command:

sudo mkfs /dev/sdb1 -t ext4

verify

sudo fdisk -l

mount the newly created sdb1 partition into other directory

or 

{

cd /mnt/
sudo mkdir 2ndHDD 
sudo chmod 0777 2ndHDD
ls -l

sudo mount /dev/sdb1 /mnt/2ndHDD -t ext4  

sudo chmod 0777 2ndHDD

touch /mnt/2ndHDD/test.txt
ls /mnt/2ndHDD/* 

} 

mount -t ext4 -v /dev/sdb1 /opt/repository/myDir
 sudo vim /etc/fstab

/dev/sdb1    /opt/repository/myDir    ext4        defaults  0    1

sudo mount -a

Vagrant: * Unknown configuration section 'berkshelf'.

Berkshalf vagrant variant has been renamed by its maintainer at
https://github.com/RiotGames/vagrant-berkshelf

Users using the old command will face the following error when
executing "vagrant up":

Vagrant:
* Unknown configuration section 'berkshelf'.

Solution:

sudo vagrant plugin install vagrant-berkshelf

vagrant up

File Share using Apache

File Share using Apache

Apache is pretty useful for sharing files on network particularly on LAN. Here is how to map an external folder to an url on your apache server. Lets assume your home directory is ABC and the path of the folder that you want to share is /var/log/weblogs. And you want to access contents of this folder at url /weblogs.

Change directory to /etc/apache2/sites-enabled. And create file named downloads with the following contents.

Alias "/weblogs" "/var/log/weblogs/"

Directory "/var/log/weblogs/"
     AllowOverride None
     Options Indexes
     Order allow,deny
     Allow from all

/Directory

Save the file and close it. Now restart the apache by issuing following command.

sudo apache2ctl restart

Now test everything is working as expected by going to following url in your browser.

http://localhost/weblogs

Reset forgotten mysql password

This works for ubuntu/Debain only & not for red hat/Centos

# /etc/init.d/mysql stop
# mysqld_safe --skip-grant-tables &
$ mysql -u root

mysql> use mysql;
mysql> update user set password=PASSWORD("password") where User='root';
mysql> flush privileges;
mysql> quit

# /etc/init.d/mysql stop
# /etc/init.d/mysql start
$ mysql -u root -p

Take Full backup of Mysql

mysqldump -u root -ppassword --all-databases > /tmp/all-database.sql 

Restore DB

mysql -u root -ppassword < /tmp/all-database.sql