Puppet, Configuration Management and How to Get into Production Faster...

Puppet or Chef?

You must take a look at the varios comparissons between the tools, but actually we chosen Puppet since it becomes an industry choice (we verified it by searching Linkedin).

What Puppet Version to choose?

I always like to explore the community editions, but PuppetLabs has a very nice offer for their Enterprise Edition (10 free nodes). Feel free to decide by yourself.

How to Install?

You can compile the source, but repositories are probably the easiest way around.

The CentOS 6.X easiest way is: $ sudo rpm -ivh http://yum.puppetlabs.com/el/6/products/i386/puppetlabs-release-6-7.noarch.rpm

How does It Actually Work?

1. Central Server/Master Repository: the place where defintions are defined. Please notice that some best practices recommend that you actually define the central server as another node in the system.
2. Nodes: these are your operational servers that gets configuration procedures from the central server.
3. Providers: perform the process on each machine, create systems abstraction (different OS distros for example) from the user.
4. Puppet Modules: these are product configuration definitions that can be installed on your server. For example the definition of Riverbed Stringray that we'll discuss later.
5. Server Configuration files: these are the configurations of each server (for example your web server). These files includes the selection of production that will be implemented and what configuration decisions were taken. For example if you install a loadbalancer on your server: what is the LB algorithm and what nodes are behind the LB.

How to Add a New Product to your Server?

Just add to the node ( in testServer this case) the product definition (class {'stingray':... in this case) and define the various configuration options (stingray::new_cluster in this case):

node 'testServer' {

    class {'stingray':

        accept_license => 'accept'

    }

    stingray::new_cluster{'new_cluster':

    }

    stingray::pool{'Northern Lights':

        nodes       => ['192.168.22.121:80', '192.168.22.122:80'],

        algorithm   => 'Least Connections',

        persistence => 'NL Persistence',

        monitors    => 'NL Monitor'

    }

}

How to implement Elastic Hosts (and server groups w/ the same function)?
If you want to implement elastic hosts that scale to traffic you should use MCollective to define the server groups

Do you need more information?
I found following PuppetLabs presentation to be very useful:


Bottom Line
Deployment of large systems is easier today, and will be even easier in the near future. You just need to choose the right tools.

Keep Performing,
Moshe Kaplan

MySQL Multi Master Replication

Why Multi Master Replication?
Master-Slave configuration is a great solution when your system is read bound. But what happens if you want to support high write loads, while keeping the option to select the data using a single SQL statement?

Multi Master replication is the solution for that. However, there are several methods in the market for that, and when choosing the right method, you should carefully define your needs: synchronous method or async one, row based or statement based (traffic between servers) and if time delayed replication is required (for quick recovery from delete for example).

The Multi Master Replication Options
I just kicked the first Israeli MySQL User Group in association with Wix this week, and I wanted to share with you Michael Naumov's presentation from our first event. 

In his talk, Michael presented four methods to support Multi Master replication: MySQL 5.6 Native, NDB, Tungsten and Galera.



Bottom Line
Careful selection of the right MySQL Multi Master replication can save you production issues and can boost your system. Now all left is to define what is needed and what is the matching solution for that.

Keep Performing,
Moshe Kaplan