Java Interview

MVC Model View Controller SOLID Design Principles Single Responsibility Principle Open-Closed Principle Liskov Substitution Principle Interface Segregation Principle Dependency Inversion Principle

Design Pattern Creational Design Patterns Factory Pattern Prototype Pattern Builder Pattern Singletons Structural Design Patterns Adapter Pattern Composite Pattern Decorator Pattern Behavioral Design Patterns Strategy Pattern State Pattern

STUPID Practices in Programming S for Singleton T for Tight Coupling U for Untestability P for Premature Optimization I for Indescriptive Naming D for Duplication

Terminology

Composition vs Aggregation Both are Association Composition: A "owns" B Aggregation: A "uses" B Network Physical Layer: Ethernet, 802.11 Data Link Layer: MAC, ARP, PPP Network Layer: IPv4, IPv6 Transport Layer Session Layer Presentation Layer Application Layer: DNS

DevOps

DevOps

The DevOps is a combination of two words, one is software Development, and second is Operations. This allows a single team to handle the entire application lifecycle, from development to testing, deployment, and operations. DevOps helps us to reduce the gap between software developers, quality assurance (QA) engineers, and system administrators.

DevOps tools such as Git, Ansible, Docker, Puppet, Jenkins, Chef, Nagios and Kubernetes.

1. Automation
2. Collaboration
3. Integration
4. Configuration

Puppet

Puppet is the most powerful configuration management tool in the solar system. It’s the engine that drives your compliance, baseline, drift remediation, and deployment needs. It has always been and always will be open source, with freely downloadable operating system-specific agent packages, a massively scalable server, and data warehousing capabilities via PuppetDB.

Ansible

Ansible is an open-source software provisioning, configuration management, and application-deployment tool enabling infrastructure as code. It runs on many Unix-like systems, and can configure both Unix-like systems as well as Microsoft Windows. It includes its own declarative language to describe system configuration. Ansible was written by Michael DeHaan and acquired by Red Hat in 2015. Ansible is agentless, temporarily connecting remotely via SSH or Windows Remote Management (allowing remote PowerShell execution) to do its tasks.

References

Use MVC, SOLID Principles and Design Patterns in Java Organize Objects With Structural Design Patterns Manage Objects With Behavioral Design Patterns Create Objects With Creational Design Patterns Avoid STUPID Practices in Programming Functions of the OSI Layers SOLID Principles in Java Computer Science Design Pattern Algorithm

DevOps Advantages & Disadvantages Ansible