One way to deal with changing IP addresses on my raspberry Pi cluster

One of the annoyances I have with my router (it's actually a hotspot) is that every time I start up my Pi cluster, they all have different IP addresses than they had the day before.

So - I have two ways to deal with this.

The first way - I scp the IP addresses as a file (after the pi's start up) to my work computer, then generate an ssh_config file. The second way, I request the same IP from my hotspot. All my Pi's are running Debian Jessie with systemd.

The first way: 

scp (or you could email it) the IP address after networking has started up.

HOW-TO use Kafka to stream Postgresql traffic with bottledwater_pg on a Raspberry Pi 3

If you want to stream changes to your Postgresql database to Kafka on your Raspberry Pi 3 - this is how I did it. I'm sure there are other ways to accomplish this. All I want to do here is to show you how I managed it. I'll preface my comments with a hash '#'.

Installing the C AVRO library on Raspbian Jessie

Reference: Apache Avro

git clone https://github.com/apache/avro.git

Install postgresql from source an Raspberry Pi 3 Debian Jessie

Reference: https://www.postgresql.org/docs/current/static/installation.html

Pretty sure I included all of the prerequisites:

Install zookeeper package

As part of the Kafka streaming project, I installed zookeeper. Here's how I did that:

Ref: Apache Zookeeper

Changing Out a Zookeeper Instance - Rolling restart

Changing Out a Zookeeper Instance:

We were recently tasked with changing out 3 (of 5) Zookeeper instances without disrupting the customer's environment. I set up a test bed using 5 independent zookeeper instances with a simulated game running on another.

Using my IPAD as an extended display using AirDisplay.

Using my IPAD as an extended display using AirDisplay.

I couldn't use AirDisplay at McDonald's or Starbuck's. The wi-fi blocked local traffic. So - this is my work-around.

In a nutshell:

• Enabled Bluetooth on both and connected my IPAD to my Mac.
• Started AirDisplay on both and connected.
• When it started up, my Mac's display shrunk to the size of my IPAD. 
• System preferences (on my Mac)
• Displays
• Arrangement - un-check 'Mirror Displays' and position the small window.