Quick intro to mongoDB for sysadmins. With a simple vagrant demo

1. mongoDB
for sysadmins
Jordi Soucheiron - @jordixou
Software developer & sysadmin @ DEXMA
@sudoersbcn 2013/6/4

2. What is mongoDB
 Document oriented noSQL database
 Auto sharding -> scales horizontally
 Auto replication -> high availability
 Atomic in-place updates
 No transaction support
 JSON queries and results
 Open source with commercial support by 10gen

3. What is it used for?
 Storing files
 Storing logs
 Queue systems
 Data mining
 …

4. Basic mongoDB setup
 Pros: Simple
 Cons: No sharding, no high-availability

5. Small mongoDB setup
 Pros: High-availability, optional delayed node
 Cons: No sharding

6. Advanced mongoDB setup

7. Advanced mongoDB setup
 Pros:
 High-availability
 Reads and writes are distributed amongst all nodes
 You choose what kind of replication you want
 You choose what collections are sharded
 You choose the sharding key
 Cons:
 More complexity than the other solutions
 You ALWAYS want 3 config servers

8. Demo time

9. Configure Vagrant
 Init Vagrant:
 Modify Vagrantfile:
Vagrant.configure("2") do |config|
config.vm.box = "precise64"
config.vm.box_url = "http://files.vagrantup.com/precise64.box"
config.vm.provision :puppet do |puppet|
puppet.manifests_path = "manifests"
puppet.manifest_file = "init.pp"
end
end
vmvagrant init precise64 http://files.vagrantup.com/precise64.box

10. Configure Puppet
 mkdir Manifests
 vi init.pp:
package { 'mongodb':
ensure => present,
}

11. Start Vagrant and mongoDB
 vagrant up
 vagrant ssh
 sudo /etc/init.d/mongodb stop
 mkdir –p ~/mongo/db1 ~/mongo/db2 ~/mongo/db3
 mongod --port 27017 --dbpath ~/mongo/db1 --replSet rs0 --
smallfiles --oplogSize 128 --rest
 mongod --port 27018 --dbpath ~/mongo/db2 --replSet rs0 --
smallfiles --oplogSize 128
 mongod --port 27019 --dbpath ~/mongo/db3 --replSet rs0 --
smallfiles --oplogSize 128

12. Add nodes to the replica set
 mongo --port 27017
rsconf = {
_id: "rs0",
members: [
{
_id: 0,
host: "127.0.0.1:27017"
}
]
}
rs.initiate( rsconf )
rs.add("127.0.0.1:27018")
rs.add("127.0.0.1:27019")

13. Questions