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Showing posts from 2015

VM vs Docker

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I keep rereading  the Docker documentation  to try to understand the difference between Docker and a full VM. How does it manage to provide a full filesystem, isolated networking environment, etc. without being as heavy? Why is deploying software to a docker image (if that's the right term) easier than simply deploying to a consistent production environment? up vote 77 down vote I like Ken Cochrane's answer. But I want to add additional point of view, not covered in detail here. In my opinion Docker differs also in whole process. In contrast to VMs Docker is not (only) about optimal resource sharing of hardware, moreover it provides a "system" for packaging application (Preferable but not a must, as a set of Microservices). To me it fits in the gap between Developer Oriented tools like rpm, debian packages, maven, npm + git on one side and Ops tools like Puppet, VMWare, Xen you name it... Why is deploying software to a docker image (if that

WMI Static Port configuration

Step one:  Set the DCOM config to use a static port.... Basically, run "dcomcnfg" from command prompt. Navigate the tree to My Computer > DCOM Config > Windows Management and Instrumentation, select properties of that folder. Go to the Endpoints tab Select Properties button for Connection-oriented TCP/IP Use static endpoint, set the port. Step 2:  Configure WMI to use a fixed port http://msdn.microsoft.com/en-us/library/bb219447(v=VS.85).aspx At the command prompt, type  winmgmt -standalonehost Stop the WMI service by typing the command  net stop "Windows Management Instrumentation" Restart the WMI service again in a new service host by typing  net start "Windows Management Instrumentation" Establish a new port number for the WMI service by typing  netsh firewall add portopening TCP 24158 WMIFixedPort Still testing this myself, so not 100% certain it works. Another way, use the Component Services Manager to set the ra

How Cassandra works?

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Loopback, Private and Public IP Addresses

Loopback Address Loopback IP address from 127.0.0.1 to 127.255.255.254? Private Address The private address space specified in RFC 1918 is defined by the following three address blocks: 10.0.0.0/8 The 10.0.0.0/8 private network is a class A network ID that allows the following range of valid IP addresses: 10.0.0.1 to 10.255.255.254. The 10.0.0.0/8 private network has 24 host bits that can be used for any subnetting scheme within the private organization. 172.16.0.0/12 The 172.16.0.0/12 private network can be interpreted either as a block of 16 class B network IDs or as a 20-bit assignable address space (20 host bits) that can be used for any subnetting scheme within the private organization. The 172.16.0.0/12 private network allows the following range of valid IP addresses: 172.16.0.1 to 172.31.255.254. 192.168.0.0/16 The 192.168.0.0/16 private network can be interpreted either as a block of 256 class C network IDs or as a 16-bit assignable address space (16 host bits)

Hadoop Story

How did Hadoop get here? As the World Wide Web grew at a dizzying pace in the late 1900s and early 2000s, search engines and indexes were created to help people find relevant information amid all of that text-based content. During the early years, search results were returned by humans. It’s true! But as the number of web pages grew from dozens to millions, automation was required. Web crawlers were created, many as university-led research projects, and search engine startups took off (Yahoo, AltaVista, etc.). One such project was Nutch – an open-source web search engine – and the brainchild of Doug Cutting and Mike Cafarella. Their goal was to invent a way to return web search results faster by distributing data and calculations across different computers so multiple tasks could be accomplished simultaneously. Also during this time, another search engine project called Google was in progress. It was based on the same concept – storing and processing data in a distributed, automa

Adding Virtualbox Guest Additions to Elementary OS

Adding Virtualbox Guest Additions to Elementary OS  Install the following packages Step 01 : sudo apt-get install build-essential module-assistant Step 02 : sudo m-a prepare Step 03 : Insert the Guest Additions tools in the CD ROM from the VM User interface Step04  : sudo ./VBoxLinuxAdditions.run Done! it works!!!

Exploring LXC Networking

Recently I’ve been finding myself in various conversations about  Docker  and  Linux Containers (LXC) . Most of the time the conversations eventually end up with one and the same question and that is whether we should run containers in production. Initially this post had a few paragraphs where I philosophised about readiness of the technology, but I’ve deleted those paragraphs now as the attention dedicated to containers in past year has been nothing short of amazing and more and more companies are running their Infrastructures in the containers or at least big parts of them. I’m sure this trend will continue to high degree in the future, so I’ve now removed these paragraphs and kept the technical content only. One of the (many) things which were not entirely clear to me and to the people I speak with about the topic of containers almost on daily basis is how the networking can be done and configured when using LXC. Hopefully the first blog post on this topic is going to shed some