41. What are playbooks in Ansible?
Playbooks are Ansible’s configuration, deployment, and orchestration language. They can describe a policy you want your remote systems to enforce or a set of steps in a general IT process. Playbooks are designed to be human-readable and are developed in a basic text language.
At a basic level, playbooks can be used to manage configurations of and deployments to remote machines.
42. When should I use the external_stage option?
Set -external_stage using WebLogic.Deployer if you want to stage the application yourself, and prefer to copy it to its target by your own means.
43. What is Nagios?
Nagios is one of the monitoring tools. It is used for Continuous monitoring of systems, applications, services, and business processes etc in a DevOps culture. In the event of a failure, Nagios can alert technical staff of the problem, allowing them to begin remediation processes before outages affect business processes, end-users, or customers.
44. What is meant by saying Nagios is Object Oriented?
One of the features of Nagios is object configuration format in that you can create object definitions that inherit properties from other object definitions and hence the name. This simplifies and clarifies relationships between various components.”
45. What is Docker container?
Docker containers include the application and all of its dependencies but share the kernel with other containers, running as isolated processes in user space on the host operating system. Docker containers are not tied to any specific infrastructure: they run on any computer, on any infrastructure, and in any cloud.
46. How to create a Docker container?
To create Docker container by using the below command:
docker run -t -i <image name> <command name>
This command will create and start the container.
You should also add If you want to check the list of all running container with status on a host use the below command:
docker ps –a
47. What types of testing are needed?
Software teams will often look for the “fair weather” path to system completion; that is, they start from an assumption that software will usually work and only occasionally fail. I believe to practice defensive programming in a pragmatic way, which often means assuming that the code will fail and planning for those failures. I try to incorporate a unit test strategy, use of test harnesses, early load testing; network simulation, A/B and multivariate testing etc.
48. What is the one most important thing DevOps helps do?
The most important thing DevOps helps to do is to get the changes into production as quickly as possible while minimizing risks in software quality assurance and compliance. That is the primary objective of DevOps. However, there are many other positive side-effects to DevOps. For example, clearer communication and better working relationships between teams which creates a less stressful working environment.
49. What are the advantages of NoSQL database over RDBMS?
The advantages are:
- Less need for ETL
- Support for unstructured text
- Ability to handle change over time
- Breadth of functionality
- Ability to scale horizontally
- Support for multiple data structures
- Choice of vendors
50. What is an MX record in DNS?
MX records are mail exchange records used for determining the priority of email servers for a domain. The lowest priority email server is the first destination for email. If the lowest priority email server is unavailable, mail will be sent to the higher priority email servers.