Apache Kafka, distributed streaming platform was originally developed by LinkedIn and used for data streaming. It is now open source platform under Apache software foundation. Programming language used for Kafka development are Java and Scala.
Kafka Architecture has producers send Key-Value messages to Kafka clusters. Data can be partitioned into different partitions under kafka topics. Kafka consumers read data from partitions.
Binary TCP based Protocol is used in Kafka.
What is a Java Constructor
A java constructor is a special method used to initialize java objects. Constructor can be used to set initial values for object attributes. Constructor is called when an object of a class is created. Constructor can also take parameters. Constructors can take many parameters they way a method takes.Constructor name should match class name. Also Constructor can not return value.
Ansible quick notes
Ansible is an IT automation tool to fulfill DevOps requirements. Ansible is written in Ruby, python, and powershell.
Ansible is used for cloud provisioning, application deployments, server patching , rebooting, configuration management, and many more IT tasks fulfillment.
Ansible Scripts are written in ansible playbook(s). I will include few sample playbooks and explain the its own declarative language below in this article.
What’s make Ansible so unique and top winner?
The main feature of Ansible is that it does not need Agents or any other special security infrastructure unlike other IT automation tools in the market.
Ansible just needs its automation jobs written in YAML file called as Ansible playbooks.
What is Ansible Role directory structure ?
Role directory structure contains tasks, handlers, vars, files, templates etc. Roles helps to automatically load these. Ansible playbook is a mapping between hosts and Roles. E.g. are site.yml, webserbers.yml etc. While roles are set of tasks and variables.
Typical ansible directory layout contains inventory files to represent production and other staging environments.There will be master playbook yml files, webserver, dbserver yml files, other libraries representing custom modules like utility, plugins yml files, group and host representatives yml files, then roles as discussed above contains set of yml files and finally if needed monitoring yml files can also be added to a playbook.
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-name: install a package
yum:
name: nginx
state: installed
validate_certs: no
skip_broken: yes
Vagrant quick notes
Vagrant is highly useful to build and maintain portable virtual software development environment by doing software configuration management.
Vagrant is developed using Ruby. Vagrant uses provisioners like puppet or chef. Also Vagrat natively supports comes providers like Docker, VMware.
Vagrant acts as a middle layer between virtualization software and providers like Docker containers.