50 Essential Q&As to Crack Your Production Support Technical Interview with Confidence

by Arnab Posted on August 14, 2024 | 22 minutes read

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Master These 50 Essential Q&As to Ace Your Production Support Technical Interview and Boost Your Success Rate!

Preparing for a production support technical interview can be a daunting task. Whether you're applying for a role as a Production/Application Support Specialist, ITSM Consultant, or Operations Consultant, you need to be ready to tackle a range of technical and situational questions. This guide will cover essential topics and provide answers to help you excel in your interview.

1. Problem vs Incident

Problem: A problem is the underlying cause of one or more incidents. Problems often require investigation and can be identified through repeated incidents or systematic analysis. For example, if users repeatedly experience slow system performance, the problem might be a faulty server configuration.

Incident: An incident is an unplanned interruption or reduction in the quality of an IT service. For example, if a user's application crashes, that is considered an incident. The primary goal is to restore normal service operation as quickly as possible.

2. The find Command in Unix

The find command is a powerful tool for searching files and directories in Unix. Here are some examples:

Find all files in a directory:

find /path/to/directory

Find files by name:

find /path/to/directory -name "filename.txt"

Find files modified in the last 7 days:

find /path/to/directory -mtime -7

Find and delete files:

find /path/to/directory -name "*.tmp" -exec rm {} \;

3. Delete vs Truncate

DELETE: This SQL command removes rows from a table based on a condition. It can be rolled back if used within a transaction. For example:

DELETE FROM employees WHERE employee_id = 100;

TRUNCATE: This SQL command removes all rows from a table and cannot be rolled back if used outside of a transaction. It is faster than DELETE because it doesn’t generate individual row delete operations. For example:

TRUNCATE TABLE employees;

4. Cursor vs Trigger

Cursor: A database cursor allows row-by-row processing of SQL queries. It’s useful for operations that require complex row handling. Example:

DECLARE cursor_name CURSOR FOR SELECT * FROM table_name;
Trigger: A database trigger is a procedural code that is automatically executed in response to certain events on a table or view. Example:

CREATE TRIGGER trigger_name
AFTER INSERT ON table_name
FOR EACH ROW
BEGIN
 -- trigger logic
END;

5. Rollback vs Commit

ROLLBACK: This command undoes transactions that have not yet been committed, restoring the database to its previous state.

ROLLBACK;
COMMIT: This command saves all changes made during the current transaction. Once committed, changes cannot be rolled back.

COMMIT;

6. What is a View?

A view is a virtual table based on the result of a SELECT query. It does not store data physically but provides a way to simplify complex queries. Example:

CREATE VIEW view_name AS
SELECT column1, column2
FROM table_name
WHERE condition;

7. Referential Integrity

Referential integrity ensures that relationships between tables remain consistent. For instance, a foreign key constraint enforces that a value in one table matches a value in another table.

8. CMDB (Configuration Management Database)

CMDB is a repository that acts as a data warehouse for IT organizations. It contains information about the components of the IT environment and their relationships. This helps in managing and tracking configuration items and their dependencies.

9. sed and awk

sed: Stream editor used for parsing and transforming text. Example:

sed 's/old-text/new-text/' filename

awk: Pattern scanning and processing language. Example:

awk '{print $1}' filename

10. Finding Latest File Among Thousands

To find the latest abc.txt among thousands of files:

find /path/to/directory -name "abc.txt" -exec ls -lt {} + | head -n 1

11. Replace Blank Columns and Lines in a File

To replace blank columns with a specific value and blank lines with a placeholder:

awk '{$1=$1;print}' file.txt | sed '/^$/d' > newfile.txt

12. Deadlock in SQL

A deadlock occurs when two or more transactions are waiting for each other to release resources, causing all to remain blocked. To resolve deadlocks, use database tools to detect them and ensure that transactions are designed to avoid circular waits.

13. Query Plan

A query plan is a detailed roadmap created by the database query optimizer. It outlines how the database engine will execute a query. Understanding the query plan helps in optimizing performance by identifying inefficiencies.

14. Emergency Change

An emergency change is a change that needs to be implemented immediately to fix a critical issue or to restore service. It bypasses some of the usual change management processes due to its urgency.

15. KPI, SLA, Metrics

KPI (Key Performance Indicator): A measurable value that demonstrates how effectively an organization is achieving key business objectives.

SLA (Service Level Agreement): A contract between a service provider and a customer that defines the level of service expected.

Metrics: Quantitative measures used to track and assess the status of a specific process.

16. Change Management Process

The change management process involves the following steps:

Request for Change (RFC): Initiate a request for a change.
Assessment: Evaluate the impact and risks.
Approval: Obtain approval from relevant stakeholders.
Implementation: Carry out the change.
Review: Assess the change post-implementation.

17. Prioritizing Multiple Issues

To prioritize multiple issues:

Assess Impact: Determine the impact on business operations.
Evaluate Urgency: Consider the urgency of resolving the issue.
Resource Availability: Check available resources for addressing issues.
Follow SLAs: Align with Service Level Agreements to ensure timely resolution.

18. Incident Closure in Problem Tickets

Incidents are generally closed in a problem ticket when the underlying issue causing the incidents has been resolved. For example, if a recurring software bug is fixed, related incident tickets can be closed once the problem is resolved.

19. Audit, Compliance, Bridge, Outage

Audit: A systematic review of systems or processes to ensure compliance with standards.
Compliance: Adherence to regulatory requirements and standards.
Bridge: A temporary solution to connect different systems or technologies.
Outage: A period during which a system is unavailable or not functioning.

20. New Process Implementation

For example, if you implemented a new automated monitoring system, you would start by identifying the need, planning the solution, testing it, and then deploying it across the organization.

21. Scrum and Agile

Scrum: An agile framework for managing and completing complex projects by breaking them into smaller tasks and working in iterative cycles called sprints.
Agile: A set of principles for software development under which requirements and solutions evolve through collaborative efforts.

Metrics Highlighted in Reports:

Status Report: Progress towards milestones, issues faced, and resolutions.
Quarterly Business Report: Financial performance, project status, and strategic goals.

22. Handling Tough/Demanding Clients

Listen Actively: Understand their concerns thoroughly.
Stay Calm: Maintain professionalism and composure.
Communicate Clearly: Provide clear and honest updates.
Offer Solutions: Focus on resolving issues rather than dwelling on problems.

23. Real Examples of Automation

An example of automation could be implementing a CI/CD pipeline using Jenkins to automate code integration and deployment.

24. ITIL Implementation

ITIL (Information Technology Infrastructure Library) provides a framework for managing IT services. Implementation involves adopting ITIL processes such as Incident Management, Problem Management, and Change Management.

25. Docker and Containerization

Docker: A platform for developing, shipping, and running applications inside containers.
Containerization: A method of virtualization that packages applications and their dependencies into containers.

Image: A lightweight, standalone, executable package that includes everything needed to run a piece of software.

26. Process of Release and Deployment

Planning: Define the scope and timeline.
Development: Code and test new features.
Release: Deploy the new features to a staging environment.
Deployment: Roll out the features to production.
Monitoring: Ensure stability and performance post-deployment.

27. Jenkins, ServiceNow, Service Catalog

Jenkins: An open-source automation server used for continuous integration and continuous delivery (CI/CD).
ServiceNow: A cloud-based platform for IT service management (ITSM) and automating business processes.
Service Catalog: A list of services provided by IT to users, allowing them to request and track services.

28. Priority Levels (P1, P2, P3, P4)
P1 (Priority 1): Critical issues impacting business operations, requiring immediate attention.
P2 (Priority 2): High-priority issues affecting significant functions but not critical.
P3 (Priority 3): Medium-priority issues with moderate impact.
P4 (Priority 4): Low-priority issues with minimal impact.

29. Server to Server Copy (Unix)

To copy files from one server to another, use scp or rsync:

scp user@source_server:/path/to/file /path/to/destination

30. Backup and Restore

Backup: Create a copy of data to prevent loss. Example:

tar -czvf backup.tar.gz /path/to/data

Restore: Recover data from a backup. Example:

tar -xzvf backup.tar.gz -C /path/to/restore

31. Index (Cluster and Non-Cluster)

Clustered Index: Sorts and stores the data rows in the table according to the index. Example: Primary key index.

Non-Clustered Index: Creates a separate structure from the data rows, containing pointers to the data. Example: Index on a column not used as a primary key.

When to Use:

Clustered Index: When the primary access pattern requires sorting.
Non-Clustered Index: When queries frequently search on non-primary key columns.

32. Joins - Advantages and Disadvantages

Inner Join: Returns records that have matching values in both tables. Fast and efficient but only returns matching records.
Left Join: Returns all records from the left table and matched records from the right table. Useful for including all records from one table.
Right Join: Returns all records from the right table and matched records from the left table.
Full Join: Returns all records when there is a match in either table.

Advantages: Allows combining related data from multiple tables.

Disadvantages: Can be resource-intensive and may result in performance issues if not used properly.

33. Query Tuning (10 Methods)

Indexing: Create indexes on frequently searched columns.
Analyze Queries: Use tools to examine query performance.
Avoid Subqueries: Replace subqueries with joins if possible.
Use Proper Data Types: Ensure columns use the most appropriate data types.
Optimize Joins: Ensure joins are efficient and use indexes.
Limit Results: Use LIMIT to reduce the number of rows processed.
Analyze Execution Plans: Identify slow operations.
Avoid Wildcards: Use specific search criteria rather than %.
Update Statistics: Keep database statistics up-to-date for better optimization.
Batch Processing: Process large data in smaller batches.
Example: If a query’s performance degrades from 40 minutes to 2 hours, check for missing indexes, increased data volume, or inefficient query design.

34. Checking Log Files

To check log files:

head: Displays the first part of files.

head -n 10 logfile.log
tail: Displays the last part of files.

tail -n 10 logfile.log
more: Allows for scrolling through the file.

more logfile.log

35. exec Command

The exec command replaces the shell with a specified program. Example:

exec ls -l
This will replace the current shell with the ls command.

Here are additional topics and questions that could be valuable for a production support technical interview. These cover various aspects of system administration, application support, and IT operations:

36. Understanding and Managing System Resources

Question: How do you check the CPU and memory usage on a Unix system?

Answer:

To check CPU and memory usage on a Unix system:

CPU Usage:

top
or
mpstat

Memory Usage:

free -m
or
vmstat

Question: What is a swap space, and how do you manage it?

Answer:

Swap space is used as an extension of the system's physical memory. It helps to manage memory more effectively by providing additional virtual memory.

Check Swap Space:

swapon -s

Create a Swap File:

dd if=/dev/zero of=/swapfile bs=1M count=1024
mkswap /swapfile
swapon /swapfile

Add to /etc/fstab:

/swapfile none swap sw 0 0

37. Networking Basics and Troubleshooting

Question: How do you troubleshoot network connectivity issues on a Unix system?

Answer:
To troubleshoot network connectivity:

Check Network Interfaces:

ifconfig

Ping a Remote Host:

ping <hostname or IP>

Check Routing Table:

netstat -rn

Test Port Connectivity:

telnet <hostname or IP> <port>

Question: What is the purpose of netstat and ss commands?

Answer:

netstat: Provides network statistics, including network connections, routing tables, interface statistics, masquerade connections, and multicast memberships.

netstat -tuln

ss: A utility to investigate sockets. It is faster and more informative than netstat.

ss -tuln

38. Log Analysis

Question: How do you analyze log files to troubleshoot issues?

Answer:

Use grep to search for specific strings:

grep "ERROR" logfile.log
Use awk to extract columns:

awk '{print $1, $2, $3}' logfile.log
Use tail -f to monitor logs in real-time:

tail -f logfile.log

39. Backup Strategies

Question: What are the different types of backups, and when would you use each?
Answer:

Full Backup: Backs up all data. It is comprehensive but time-consuming and requires significant storage space.

Incremental Backup: Backs up only the data that has changed since the last backup. It is faster and uses less storage but requires all previous backups for restoration.

Differential Backup: Backs up data changed since the last full backup. It is faster than a full backup and easier to restore compared to incremental backups.

Question: How would you restore data from a backup?

Answer:

To restore data from a backup:

Identify Backup Files: Locate the backup files or images.
Stop Services: Ensure that the services using the data are stopped.

Restore Backup:

For file-based backups:

tar -xzvf backup.tar.gz -C /path/to/restore
For database backups, use the appropriate restoration commands for your database system (e.g., mysql, pg_restore).

40. Security Practices

Question: What are some best practices for securing a Unix server?

Answer:

Use Strong Passwords: Ensure passwords are complex and changed regularly.
Implement Firewall Rules: Configure firewalls to allow only necessary traffic.
Regular Updates: Apply security patches and updates regularly.
Disable Unused Services: Turn off services and daemons that are not in use.
Monitor Logs: Regularly check logs for unauthorized access or anomalies.
Use SSH Keys: For remote access, use SSH keys instead of passwords.

Question: How do you secure a database?

Answer:

Use Strong Authentication: Implement strong password policies and roles.
Encrypt Data: Use encryption for data at rest and in transit.
Limit User Privileges: Grant only necessary privileges to users.
Regularly Update: Apply security patches and updates.
Monitor Access: Keep track of database access and queries.

41. Handling System Failures

Question: What steps would you take if a critical system goes down?

Answer:

Assess the Situation: Determine the scope and impact of the failure.
Communicate: Inform relevant stakeholders and users about the outage.
Identify the Cause: Investigate logs, alerts, and recent changes to find the root cause.
Implement a Fix: Apply a temporary fix to restore service or roll back recent changes.
Document the Incident: Record details of the incident and resolution steps.
Conduct a Post-Mortem: Analyze the incident to prevent future occurrences and improve processes.

42. Version Control and Deployment

Question: What is version control, and why is it important?

Answer:

Version control is a system that manages changes to source code or files over time. It allows teams to track revisions, collaborate on code, and revert to previous versions if needed. It is crucial for managing changes, ensuring code quality, and maintaining historical records.

Question: Describe the process of deploying an application using Jenkins.

Answer:

Set Up Jenkins: Install and configure Jenkins on your server.
Create a Job: Set up a new Jenkins job (build pipeline) to manage your deployment process.
Configure Source Control: Link the job to your version control system (e.g., Git).
Define Build Steps: Add build steps such as compiling code, running tests, and creating artifacts.
Set Up Deployment: Add steps for deploying the application to the target environment (e.g., staging or production).

Trigger Builds: Set up triggers for automatic builds (e.g., on code commits).
Monitor Builds: Review build results and logs to ensure successful deployment.

43. ITIL and ITSM Concepts

Question: What is the purpose of Incident Management in ITIL?

Answer:

Incident Management aims to restore normal service operation as quickly as possible while minimizing impact on the business. It involves identifying, logging, categorizing, prioritizing, and resolving incidents to ensure a smooth IT service experience.

Question: What is a Change Advisory Board (CAB)?

Answer:

A Change Advisory Board (CAB) is a group of stakeholders responsible for evaluating and approving changes to the IT environment. They assess the potential impact, risk, and benefits of proposed changes to ensure they align with business goals and minimize disruption.

44. Automation and Scripting

Question: How would you automate a repetitive task using a shell script?

Answer:

Identify the Task: Define the task and its steps.

Write the Script: Create a shell script to automate the task. For example:

#!/bin/
for file in /path/to/files/*.txt; do
 mv "$file" /path/to/destination/
done

Make it Executable:

chmod +x script.sh

Schedule it with Cron (if needed):

crontab -e
# Add entry to run script daily at midnight
0 0 * * * /path/to/script.sh

Question: Describe a scenario where you implemented automation and its impact.

Answer:

An example scenario could be automating the backup process using a shell script and cron jobs. By automating daily backups, I was able to ensure that critical data was backed up regularly without manual intervention, reducing the risk of data loss and freeing up time for other tasks.

45. Database Optimization

Question: What are some common methods for optimizing SQL queries?

Answer:

Use Indexes: Create indexes on columns used in WHERE clauses and joins.
Optimize Joins: Ensure joins are using indexes and are properly structured.
**Avoid SELECT ***: Specify only the columns needed.
Use WHERE Clauses: Filter rows as early as possible.
Analyze Execution Plans: Review execution plans to identify bottlenecks.
Optimize Subqueries: Convert subqueries to joins where appropriate.
Limit Results: Use LIMIT clauses to restrict result sets.
Update Statistics: Keep database statistics up-to-date.
Partition Tables: Split large tables into smaller partitions.
Use Caching: Implement caching mechanisms to reduce database load.

Question: What is the impact of normalization and denormalization?

Answer:

Normalization: Organizes database schema to reduce redundancy and improve data integrity. It involves dividing tables into related tables. It can improve query performance but might require more complex queries and joins.

Denormalization: Combines tables to reduce the need for joins and improve read performance. It can speed up queries but may lead to data redundancy and increased storage requirements.

46. Incident Response and Problem Management

Question: How do you differentiate between an incident and a problem?

Answer:

Incident: An unplanned interruption or reduction in the quality of an IT service. The goal is to restore normal service operation as quickly as possible.

Problem: The underlying cause of one or more incidents. Problem management involves identifying and addressing the root cause to prevent future incidents.

Question: What is an Emergency Change, and how is it handled?

Answer:

An Emergency Change is a change that must be implemented immediately to resolve a critical issue or prevent significant business impact. The process involves:

Identification: Recognize the need for an emergency change.
Authorization: Obtain approval from relevant stakeholders.
Implementation: Apply the change quickly and carefully.
Review: Post-implementation review to ensure the change resolved the issue without introducing new problems.

47. Process Improvement

Question: How do you establish a new process in IT operations?

Answer:

Identify Needs: Determine the need for a new process or improvement.
Define Objectives: Set clear goals and objectives for the process.
Design the Process: Develop a detailed plan, including steps, roles, and responsibilities.
Implement: Roll out the process and provide training to relevant stakeholders.
Monitor: Track the performance and effectiveness of the process.
Review and Improve: Collect feedback and make adjustments as necessary.

48. Scrum and Agile Methodologies

Question: What is Scrum, and how does it differ from Agile?

Answer:

Scrum: A specific framework within Agile methodologies used for managing complex projects. It involves roles such as Scrum Master, Product Owner, and Scrum Team, and uses artifacts like Product Backlog and Sprint Backlog with iterative Sprints.

Agile: A broader set of principles and practices for iterative and incremental development. Agile emphasizes flexibility, collaboration, and customer feedback. Scrum is one of many frameworks that follow Agile principles.

Question: What metrics do you highlight in a project progress report?

Answer:

Velocity: The amount of work completed in a Sprint.
Burndown Chart: Shows the remaining work versus time.
Lead Time: The time taken from the start to completion of a task.
Cycle Time: The time taken to complete a task from the moment it starts.
Defect Density: The number of defects per unit of work completed.

Here are a few additional questions and answers that could further enhance the coverage:

49. Configuration Management

Question: What is Configuration Management, and why is it important?

Answer:

Configuration Management involves maintaining the consistency of a system's performance and functional attributes with its design and operational information throughout its lifecycle. It is important because it ensures that systems are accurately documented and configurations are controlled, which helps in reducing errors, facilitating troubleshooting, and ensuring compliance with standards.

Question: How do tools like Ansible or Puppet fit into Configuration Management?

Answer:

Ansible: An open-source tool that automates configuration management, application deployment, and task automation using simple YAML files. It is agentless and uses SSH for communication.

Puppet: A configuration management tool that automates the deployment and management of software and systems. It uses a declarative language to define system configurations and ensures that systems are consistently configured according to the specified state.

50. Disaster Recovery

Question: What is a Disaster Recovery Plan (DRP), and what are its key components?

Answer:

A Disaster Recovery Plan (DRP) is a documented process that outlines how to recover and protect a business IT infrastructure in the event of a disaster. Key components include:

Risk Assessment: Identifying potential threats and vulnerabilities.
Recovery Objectives: Defining Recovery Time Objectives (RTO) and Recovery Point Objectives (RPO).
Backup Procedures: Detailed steps for data backup and restoration.
Roles and Responsibilities: Assigning specific tasks to team members.
Communication Plan: Strategies for internal and external communication during a disaster.
Testing and Maintenance: Regularly testing the plan and updating it as needed.

Question: What is the difference between RTO and RPO?

Answer:

Recovery Time Objective (RTO): The maximum acceptable amount of time that an application can be down after a disaster. It defines how quickly services must be restored.

Recovery Point Objective (RPO): The maximum acceptable amount of data loss measured in time. It determines how frequently data should be backed up to minimize data loss.

51. Capacity Planning

Question: What is capacity planning, and why is it crucial in IT operations?

Answer:

Capacity planning is the process of determining the resources required to meet future workload demands. It involves forecasting future growth and ensuring that the infrastructure can handle increased loads without performance degradation. It is crucial because it helps avoid resource shortages, maintain performance, and ensure scalability.

Question: How do you perform capacity planning for a database?

Answer:

Analyze Current Usage: Review current resource utilization and performance metrics.
Forecast Growth: Estimate future data volumes, transaction rates, and user loads.
Identify Bottlenecks: Determine potential performance limits and constraints.
Plan for Scalability: Design a scalable architecture that can handle anticipated growth.
Implement Monitoring: Continuously monitor performance to adjust plans as needed.

52. Application Performance Monitoring (APM)

Question: What is Application Performance Monitoring, and what tools are commonly used?

Answer:

Application Performance Monitoring (APM) involves tracking and managing the performance of software applications to ensure they meet performance standards and user expectations. Common APM tools include:

New Relic: Provides real-time performance monitoring and insights into application performance.
Dynatrace: Offers end-to-end monitoring and AI-driven performance management.
AppDynamics: Delivers deep visibility into application performance and user experience.

Question: What metrics are important for monitoring application performance?

Answer:

Response Time: The time it takes for an application to respond to a user request.
Throughput: The number of requests processed by the application in a given time period.
Error Rate: The percentage of requests that result in errors.
Resource Utilization: CPU, memory, and disk usage of the application.
User Satisfaction: Metrics related to user experience and satisfaction.

53. Version Control Systems

Question: What are the benefits of using Git for version control?

Answer:

Branching and Merging: Allows multiple developers to work on different features simultaneously and merge changes seamlessly.
History Tracking: Maintains a history of changes made to files, enabling rollback to previous versions if needed.
Collaboration: Facilitates collaboration among team members by providing tools for code review and sharing.
Distributed System: Each user has a complete copy of the repository, allowing work to be done offline and changes to be synchronized later.

Question: How do you resolve merge conflicts in Git?

Answer:

Identify the Conflict: Git will mark the conflict in the file with conflict markers (<<<<<<, ======, >>>>>>).
Edit the File: Manually resolve the conflict by editing the file to include the desired changes.
Mark as Resolved: After resolving the conflict, add the file to the staging area:

git add <filename>
Commit the Changes: Commit the resolved changes:

git commit -m "Resolved merge conflict in <filename>"

54. Service Level Management

Question: How do you define and measure Service Level Agreements (SLAs)?

Answer:

Define SLAs: SLAs should outline the expected performance levels, such as response times, resolution times, and availability.
Measure SLAs: Track performance metrics against SLA targets using monitoring tools and reports. Key performance indicators (KPIs) are used to measure adherence to SLA terms.

Question: What is the difference between KPIs and metrics in IT service management?

Answer:

KPIs (Key Performance Indicators): Specific, measurable values that indicate how well an organization is achieving key business objectives. They are often tied to strategic goals and are used to evaluate success.

Metrics: Quantitative measures used to track and assess various aspects of service performance and processes. While KPIs are a subset of metrics, not all metrics are KPIs. Metrics provide detailed data that supports KPI measurement.

Preparing for a production support technical interview requires a thorough understanding of various technical concepts and practical problem-solving skills. By mastering topics such as Unix commands, SQL operations, ITIL processes, and database management, you can confidently approach your interview and showcase your expertise. This guide provides a comprehensive overview and answers to common questions that will help you in your preparation. Good luck!

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