Nagios Interview Questions and Answers: Domain Skill, Soft Skill and Scenario Based

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by StarAgile

March 30, 2021
Category DevOps


Description

Nagios is an application that is fundamental for any organization, big or small, to monitor its network. The job market for a Nagios professional is vast but demanding. 

Moreover, the field is quite competitive, and you need to prove your skills in the interview to get a job. An interviewer asks questions to analyze your knowledge. Refer to these basic Nagios interview questions and answers to brush your understanding. 

Introduction

The interviewer poses questions to determine whether you have the desired skill set for the job. You are the right fit provided you demonstrate your knowledge of Nagios application before the interviewer. These Nagios interview questions offer an insight into what to expect during the interview. 

Overview

Nagios was released in the market in 1999 under the name Netsaint. Since then, it has spread globally as a monitoring tool for mission-critical network infrastructures. A Nagios consultant or a Nagios architect should have outstanding knowledge in Nagios implementation across the organization's network. 

Here are a few selected domain-based, soft skill-based & scenario-based Nagios interview questions and answers to help you excel in the interview. 

Domain Skill Based Questions

1. What are the Core Benefits of Nagios?

The core benefits of Nagios are: -

• Monitoring: Nagios is configured to monitor critical IT infrastructure components, including network protocols, system metrics, services, applications, servers, and network infrastructure.

• Alerting: Nagios is capable of sending alerts when critical infrastructure components fail and recover. It provides administrators with notice of important events via SMS, email, or custom script.

• Response: The IT team can immediately respond to alerts and begin resolving outages. They can also start investigating security alerts if any. 

• Reporting: Nagios provides reports on a historical record of outages, events, notifications, and alert responses. Availability of reports and timely review help ensure that Service Level Agreements are met.

• Maintenance: Nagios prevents alerts during scheduled downtimes meant for maintenance and upgrades windows.

• Planning: Nagios provide trending and capacity planning graphs and reports. It allows you to identify necessary infrastructure upgrades before failures occur.

• Multi-Tenant Capabilities: Access can be given to multiple users, and user-specific views can be configured to ensure that clients see specific information.

• Problem Rectification: Nagios can automatically restart any events triggered by the system, by the user, or in other ways like failed applications, devices, services.

• Expandable Architecture: Multiple Application Programming interfaces provide efficient interaction between in-house/third-party applications and community-developed add-ons.

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2. What Does the NRPE Add-On Consist Of?

The NRPE add-on comprises of two pieces:

• The check_nrpe plugin that resides on the local monitoring machine

• The NRPE daemon that runs on the remote Linux/Unix machine

3. Give Some Examples of Databases That Support Nagios?

Many databases support Nagios. Oracle, Postgres, Microsoft SQL solutions, and MySQL, to name a few. 

4. What Determines When and How Each Specific Check is Scheduled and Executed?

Each object definition has three options that define when and how a check is done.

• check_interval

• retry_interval

• check_period 

5. How Time Periods Work with Notification Escalations?

An optional escalation period directive is present in service and host notification escalations. It is used to specify a time period when the escalation is valid and can be sent out. If the escalation period directive is not specified in an escalation definition, the escalation is considered valid at all times. Nagios Core will only use the specified escalation definition during times that are valid in the time period definition.

6. Explain how Volatile Services are Useful? 

Volatile services are helpful for monitoring:

• things that reset themselves to an "OK" state automatically every time they are checked.

• events like security alerts which require attention whenever there's a haul (and not just the primary time)

Soft Skill Based Questions

You may answer such soft skill-based Nagios interview questions in the following way:

7. As a System Monitoring Architect, what is your approach to business?

Any business thrives on its customers. Our business growth is possible when the customer grows. Only system monitoring and reporting daily cannot be a good business approach. Advising the client on optimizing the system utilization through enhanced data security, highlighting future challenges & providing a proactive solution can create a win-win situation both for the client and our business. 

8. You work for an IT management company that is a vendor of a local e-commerce retailer. How can you assure the client that you are a single-point contact for all their system needs?

I will meet the client to understand their challenges & expectations. I must have the ability to describe technical information in easy-to-understand language so that the client is assured. Apart from scheduled downtime for maintenance, the system should be up. In case of any difficulty, paying attention to detail with a technical & organized mind will help resolve it quickly. Regular contact with the client is a must for fulfilling all the agreements of the contract.

Scenario-Based Questions

The following are some suggestive answers for scenario-based questions. You may answer such Nagios interview questions in the following way.

9. What will be your priority, regular monitoring of the host/service as per the contract or any urgent client request?

Meeting the client's expectations is the utmost priority. All requests that come from the client are based on the contract agreement. 

For example, check scheduling and execution are done to fulfil the client's requirements on a day-to-day basis. But individual checks are marked as low priority events in Nagios if high priority events need to be executed. If the client's urgent need is a high-priority event like log file rotations, reaper events, and external command checks, then host checks will delay service checks' execution and processing. 

This way, I can meet the client's urgent request and follow the primary contract.

10. You have got the job of a system administrator in an e-commerce company. On the first day of your work, the boss says that most of the notifications sent to the stakeholders are ignored. How will you deal with this problem?

Listening to the problem statement is the first step. Proper listening will help me to analyze the problem and find the root cause. I will assure my boss that the problem will be resolved within a day. (adding a time frame, i.e., one day, makes the answer more specific and reliable).

I will speak to the stakeholders to understand why they ignored the notifications. They might ignore it because there were so many false positives. 

Next, I will check the system and convert notifications to Nagios alerts and escalations with specific time periods for different groups of stakeholders. I will also configure event handlers to restart services before notification. 

I will go back to my stakeholders to recheck whether there has been a reduction in notifications of false positives. Last, I will inform my boss that the problem is fixed.

Conclusion

Both technical & soft skills are required to ace an interview & finally thrive in a job. Technical skill is a must, but it has to be complemented with soft skills.

Nagios is the most favored continuous monitoring application across companies worldwide. As a Nagios architect, recruiters would expect you to be familiar with Nagios' features and how 

Enroll our DevOps Training to learn in detail about this Nagios tool and make an enquiry about DevOps certification training.