Kubernetes on Windows

I came across an article from Microsoft, which confirms, that with Kubernetes version 1.14, we can run Windows Containers on our Kubernetes Clusters.

This does not means that you can run Windows Containers on a Linux based Kubernetes host, we still need a Windows Server where we can run Windows based containers.

Windows Server 2016 and Windows Server 2019 can run Kubernetes, its sad to see that Windows Server 2012 is not supported, so if you are spinning up a Windows Server node or instance, make sure you go the right version, my recommendations would be Windows 2019.

Oracle Java is no longer free

I was trying to install Oracle Java 8, in one of my projects today and I found that Oracle would not install on my Linux operating system, (I am using Ubuntu 18.04, trying to install through apt-get).

sudo apt-get install oracle-java8-installer
Reading package lists… Done
Building dependency tree
Reading state information… Done
Package oracle-java8-installer is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package ‘oracle-java8-installer’ has no installation candidate

So I tried to find a solution, visited various websites, but none of the suggested methods worked, later, I landed on this page –

https://launchpad.net/~webupd8team/+archive/ubuntu/java

Here, it is clearly said that support for Oracle Java PPA Installer is discontinued, from April 16, 2019, as Oracle Java is Free for personal and development use, but you need to have an active subscription (paid) to continue using Oracle Java for commercial purpose.

Here are the subscription options, please note that price and product availability may vary as per your country, the prices below are for US –

Oracle Java SE Desktop Subscription
1 Year Term Subscription that combines Java SE Licensing and Support for use on Desktops, Servers or Cloud deployments.
US$15.00 – US$30.00
Oracle Java SE Subscription
1 Year Term Subscription that combines Java SE Licensing and Support for use on Desktops, Servers or Cloud deployments.
US$150.00 – US$300.00
Oracle Java Development Tools Support
Support for NetBeans, Oracle JDeveloper and Oracle Enterprise Pack for Eclipse.
US$1,200.00

If you don’t want to pay for using Java, then you need to switch to Open JDK, its available for free for both commercial and personal use.

Running VMWare on IBM Cloud

Recently I had an opportunity to work on VMware VSphere on IBM Cloud, the experience was somewhat good, It was good to see that IBM is now offering VSphere as a Service.

We created a cluster of VMware VSphere with four ESXi hosts, with NSX.

The service quality is good, we could reach 100% uptime for our cluster within 2-3 weeks of deployment.

If you are hosted on a Datacenter and if you are looking for a cloud alternative to host your vmware cluster, I would suggest you can try IBM Vmware, we had tested around 600 vms and the results were satisfactory.

How to solve docker stuck containers

If you are managing a Docker cluster, then probably stuck containers would not be a new thing for you, here I will explain how to fix docker stuck containers.

As per my experience, containers get stuck due to the following reasons –

  1. Docker Networking – Containers using Docker networks get stuck more often
  2. If the container scripts (init/Shutdown) are not written properly, that is, they dont kill/stop all running services
  3. Java Programs – I have seen containers running Java (Open JDK) gets stuck more often, may be due to some bugs or some other reasons.

How to solve Docker Stuck Containers

  • Disconnect the container from Docker Network

docker network disconnect “<network_id>” “<container_id>”

  • Stop Docker Container

docker stop <container_id>

  • Forcibly Remove Container

docker rm -f <container_id>

 

Docker vs VMWare

Ah, an interesting topic which I have been searching for while learning Docker, i did not find something easy to understand, so here is what I have for you:

Docker Vs VMWare

Before starting to compare, let us first understand what both of these technologies are:

Docker: A daemon, which runs on a host system, runs child processes which are compatible with Host system, in an isolated environment, the good thing is, Docker is both available for both Linux and Windows platform, so if you want to run some Windows apps inside a container, you need a system with Windows Server 2016 and Docker EE. Same for linux, Docker supports various Linux distributions like RHEL, CentOS, UBuntu and Amazon Linux. Please note, you cannot run Windows containers on Linux and vice versa.

 VMWare VSphere: VMWare VSphere is a virtualization technology, which runs on a Hypervisor, it creates a virtual pc where you can install any operating system (for example – Windows or Linux) and then manage it just like a machine. Your applications run in a complete isolated environment, but your applications also need a Guest Operating System, a layer which you need to create for every virtual machine you spin off.

Docker vs VMWare: The Big Difference

Assume that your company requires 50 Windows Applications where each of your application requires 2GB of RAM and 50GB of disk, lets see how much does it costs on both scenarios.

Requirements of Our Applications –

 Operating System RAM Disk
 Windows Applications 2 x 50 GB 50 x 50 GB
 Total  100 GB  2500 GB

Docker

With Docker, you rent a Single server for Windows Application with config as 120GB of RAM, 250 GB of SSD for Server Operating System and a NFS volume of 2.5 TB, you are good to go.

VMWare

On vmware, apart from the above requirements of your applications, you need to add more RAM and Disk, to support guest operating system, so the calculations would be:

Operating System RAM Disk
 Windows Applications 2 x 50 GB 50 x 50 GB
 Guest OS 2 x 50 GB 30 x 50 GB
 Total  200 GB  4000 GB

So, if you proceed  with VMWare, you are going to spend 100 GB of extra RAM and around 1250 GB of additional disk, the example was of only 50 applications, assume that it was 1500 applications, where do you save more?