Final Part 3

Question 1

Why is trouble shooting often viewed as an innate skill that some people have and others don’t?

Answer 1

For those who troubleshoot often, it’s an ingrained process; explaining how to troubleshoot is difficult, much like explaining how to ride a bike.

However, troubleshooting is both learnable and teachable.

Question 2

What two factors explain why novices are often tripped up by troubleshooting?

Answer 2

An understanding of how to troubleshoot normally (i.e., without any particular system knowledge) and a solid knowledge of the system.

Question 3

Hypothetico-deductive method

Answer 3

Given a set of observations about a system and a theoretical basis for understanding system behavior, we iteratively hypothesize potential causes for the failure and try to test those hypotheses.

Question 4

What are the steps in a ideal troubleshooting model?

Answer 4

We’d start with a problem report telling us that something is wrong with the system.

Then we can look at the system’s telemetry and logs to understand its current state.

This information, combined with our knowledge of how the system is built, how it should operate, and its failure modes, enables us to identify some possible causes.

Question 5

Postmortem

Answer 5

A written record of an incident,

its impact, the actions taken to mitigate or resolve it,

the root cause(s),

the follow-up actions to prevent the incident from recurring.

Question 6

Why are Postmortems needed?

Answer 6

If incidents don’t have some formalized process of learning from, the incidents can multiply in complexity or even cascade, overwhelming a system and its operators and ultimately impacting our users.

Question 7

Reasons to monitor a system include

Answer 7

Analyzing long-term trends

Comparing over time or experiment groups

Alerting

Question 8

The four golden signals of monitoring

Answer 8

Latency, traffic, errors, and saturation

If you can only measure four metrics of your user-facing system, focus on
these four.

Question 9

Latency

Answer 9

The time it takes to service a request. It’s important to distinguish between the latency of successful requests and the latency of failed requests. It’s important to track error latency, as opposed to just filtering out errors.

Question 10

Traffic

Answer 10

A measure of how much demand is being placed on your system, measured in a high-level system-specific metric.

Question 11

Errors

Answer 11

The rate of requests that fail, either explicitly (e.g., HTTP 500s), implicitly, or by policy (for example, “If you committed to one-second response times, any request over one second is an error”).

Question 12

Saturation

Answer 12

How “full” your service is. A measure of your system fraction, emphasizing the resources that are most constrained (e.g., in a memory-constrained system, show memory; in an I/O-constrained system, show I/O).

Question 13

If you measure all four golden signals and page a human when one signal is problematic

Answer 13

Your service will be at least decently covered by monitoring

Question 14

Why is boring a positive attribute of software?

Answer 14

You don’t want programs to be spontaneous and interesting; you want them to stick to the script and predictably accomplish their business goals.

Question 15

What is the difference between essential complexity and accidental complexity?

Answer 15

Essential complexity is the complexity inherent in a given situation that cannot be removed from a problem definition, whereas accidental complexity is more fluid and can be resolved with engineering effort.

Question 16

Jenkins

Answer 16

A continuous integration server written in Java. You can use it for testing and reporting changes in near real-time. Being a developer, it will help you to find and solve bugs in your code rapidly and automate the testing of their build.

Question 17

Jenkins Features

Answer 17

– Free Open-Source Tool
– Integrate all your DevOps stages with the help of around 1000 plugins
– Script your pipeline having one or more build jobs into a single workflow
– Easily start your Jenkins with its WAR file
– Provides multiple ways of communication: web-based GUI, CLI and REST API

Question 18

What is the purpose of configuration management(CM)

Answer 18

Ensure the integrity of a product or system throughout its life-cycle by making the development or deployment process controllable and repeatable, therefore creating a higher quality product or system.

Question 19

The CM process allows orderly management of system information and
system changes for purposes such as to:

Answer 19

– Revise capability,
– Improve performance,
– Reliability or maintainability,
– Extend life,
– Reduce cost,
– Reduce risk and
– Liability, or correct defects.

Question 20

Chef

Answer 20

Configuration management technology used to automate the infrastructure provisioning. (The prerequisite steps in managing access to data and resources and facilitating systems and users’ availability. )

An automation tool that provides a way to define infrastructure as code.

Question 21

Infrastructure as code (IAC)

Answer 21

Managing infrastructure by writing code (Automating infrastructure) rather than using manual processes.

Programmable infrastructure

Question 22

The types of automation done by Chef, irrespective of the size of infrastructure are:

Answer 22

• Infrastructure configuration
• Application deployment
• Configurations that are managed across your network

Question 23

Chef Features

Answer 23

– Another open-source configuration management tool
– Supports multiple platforms like AIX, RHEL/CentOS, FreeBSD
– Easy to integrate with cloud-based platforms
– Active, smart and fast-growing community support

Question 24

Companies using chef

Answer 24

Mozilla Firefox, Expedia, Walt Disney, hp, Facebook, and Rackspace

Question 25

Advantages of Chef

Answer 25

• Fully automated deployment
• Within a minute you can configure thousands of nodes.
• Integrate with a cloud-based platform like AWS.
• Chef keeps the system under consistent check.
• You can record the entire infrastructure in the form of chef repository.
• The chef plays a vital role in DevOps software lifecycle

Question 26

Disadvantages of Chef

Answer 26

• Lacking documentation.
• Chef needs code-based knowledge for scripting the tool which makes it complicated.
• The master node can only be configurable in the Linux\Unix platform.

Question 27

What are the benefits of Chef?

Answer 27

Expedite Software Distribution

Enhances Service Flexibility

Remodels Risk Management

Collates your Infrastructure

Question 28

Ansible

Answer 28

An open-source tool that provides one of the simplest ways to automate your apps and IT infrastructures such as network configuration, cloud deployments, and creation of development environments.

Question 29

Ansible Features

Answer 29

– Open source configuration management tool
– Supports push configuration
– Based on master-slave architecture
– Completely agentless and uses simple syntax written YAML

Question 30

Companies that use Ansible

Answer 30

CapitalOne, NASA, and Viasat

Question 31

Companies that use Jenkins

Answer 31

Pentaho

OpenStack

AngularJS

Capgemini

Luxoft

Linkedin

Question 32

What does Ansible aim to do?

Answer 32

It aims to provide large productivity gains to a wide variety of automation challenges.

Question 33

Why do we need Ansible?

Answer 33

As data centers grew, and hosted applications became more complex, administrators realized they couldn’t scale their manual systems management as fast as the applications they were enabling by hand. It also hampered the velocity of the work of the developers since the development team was agile and releasing software frequently, but IT operations were spending more time configuring the systems.

Question 34

What problem is Ansible a solution Ansible solves

Answer 34

We need to keep updating, pushing changes, copying files on them
etc. These tasks make things very complicated and time-consuming.

Question 35

Nagios

Answer 35

A powerful monitoring system that enables organizations to identify and resolve IT infrastructure problems before they affect critical business processes.

Question 36

What does Nagios do?

Answer 36

It executes a continuous check on the crucial application, server resources, network, and tasks.

Monitors the memory usage of monitor and disk, the load of the microprocessor, number of processors, and logs currently running.

It can also check other services like Post office protocols 3, Simple Mail Transfer Protocol, HTTP protocols, and other available standard network protocols.

Question 37

The active and important checks are triggered by______, whereas the other secondary checks are triggered by ______ applications linked to the monitoring tool.

Answer 37

Nagios

External

Question 38

Nagios Architecture

Answer 38

1. The scheduler is a component of the server part of Nagios. It sends a signal to execute the plugins at the remote host.
2. The plugin gets the status from the remote host
3. The plugin sends the data to the process scheduler
4. The process scheduler updates the GUI and notifications are sent to admins

Question 39

What three separate products does Nagios consist of?

Answer 39

Nagios XI

Nagios Log Server

Nagios Fusion

Question 40

What do continuous monitoring tools help resolve?

Answer 40

Any system errors (low memory, unreachable server etc.) before they have any negative impact on your business productivity.

Question 41

What are Important reasons to use a monitoring tool?

Answer 41

– It detects any network or server problems

– It determines the root cause of any issues

– It maintains the security and availability of the service

– It monitors and troubleshoots server performance issues

– It allows us to plan for infrastructure upgrades before outdated systems cause failures

– It can respond to issues at the first sign of a problem

– It can be used to automatically fix problems when they are detected

– It ensures IT infrastructure outages have a minimal effect on your organization’s bottom line

– It can monitor your entire infrastructure and business processes

Question 42

When does continuous monitoring come into the picture?

Answer 42

Once the application is deployed on the production servers.

Question 43

What is continuous monitoring about?

Answer 43

The ability of an organization to detect, report, respond, contain and mitigate the attacks that occur, in its infrastructure.