Rolling Restart in Apache ZooKeeper to dynamically add servers to the Ensemble

As of the writing of this post there is currently no way in Apache ZooKeeper to dynamically add a master ZooKeeper server to the ZooKeeper Ensemble.  That is until https://issues.apache.org/jira/browse/ZOOKEEPER-107 is resolved. As a work around there is a process known as the ZooKeeper ensemble rolling restart to get around this issue. When you specify […]

Nagios – Opinions and Feedback

I have been using Nagios for several years (http://www.nagios.org/) – and realized the other day that I have never written my formal opinions on the system. In a nutshell – I love Nagios.  It works fantastically.  At the same time – I am incredibly surprised that there is not mor business insights, reporting or analysis […]

Client connection timeout or disconnect errors with Apache ZooKeeper

Several users of ZooKeeper have reported problems relating to disconnects and expired sessions from the client. For most users they are using standard settings out of the box for ZooKeeper with their tickTime=2000 and timeout set to 8000ms. Some users have reported this to be caused by something known as being oversubscribed on the service. […]

Evernote

One of my favorite tools has to be Evernote. http://www.evernote.com/ It is such a simple and straight forward program… it takes notes… so what exactly makes this tool so wonderful?  Well – the way I see it is the collaboration.  Basically your notes are stored online on their servers. This allows you to login from […]

Enabling the Group Host files module in PDSH

Once you have installed PDSH you may want to take advantage of group host files.  This allows you to dictate a file, known as a group file, with a list of hosts inside of it.  You can then pass the name of the group file to your PDSH command to execute your commands against all […]

How do you Install PDSH?

How do you install PDSH? Parallel Distributed Shell (PDSH) allows the execution of the same command in parallel on multiple machines.  This post will quickly describe how to install PDSH. If you need to, you can download the source packages of the latest PDSH release from http://downloads.sourceforge.net/pdsh/ Install PDSH using the following command: rpm -ivh pdsh-RELEASE.src.rpm […]

Make the SUM better then the PARTS

As a manager of an engineering team it can often be very difficult to know exactly what you should be focusing on.  This lack of clarity can often be your team’s undoing.  For this reason there is a simple mandate that I have found extremely helpful.  Make the sum better then the parts. What exactly […]

Installing a PHP Pear Module

How do you install a PHP Pear Module? pear install <module-name> So – if you wanted to instal the Pear Pager module use: pear install Pager If the install was successful you shoudl see something to the extent of: downloading Pager-2.4.8.tgz … Starting to download Pager-2.4.8.tgz (36,122 bytes) ……….done: 36,122 bytes install ok: channel://pear.php.net/Pager-2.4.8 Note […]

Celebrate Success

It might seem like a trivial thing – but success needs to be celebrated.  Find achievements to celebrate within your team. I have never met a person who does not want to succeed in their life.  Success is also contagious and provides a valuable fuel to get projects and other great works accomplished. This could […]

Research -> Connect -> Develop

Entrepreneurs know the importance of researching their target market and developing a solution that fits those needs.  There is a step however in between research and develop that is often over looked.  That is the idea of connecting with others after researching and before developing. SC Johnson and company has a terrific example that demonstrates […]