Ultimate Operations Engineer Interview Questions: 1000+ Essential Topics

Below is a compilation of over 1000 interview questions gathered from dozens of companies for operations engineers, covering a wide range of topics.

Question counts include:

174 Operations Engineer questions

128 Kubernetes (k8s) questions

108 Shell script questions

200 Linux questions

51 Docker questions

35 Jenkins questions

78 MongoDB questions

17 Ansible questions

60 Dubbo questions

53 Kafka questions

18 MySQL questions

40 Nginx questions

77 Redis questions

28 Zookeeper questions

1. What is operations? What is game operations? 2. When working, operations staff often need to interact with product staff; what does a product staff do? 3. Given three hundred servers, how would you manage them? 4. Describe the working principles and characteristics of RAID0, RAID1, and RAID5. 5. What are the differences among LVS, Nginx, and HAProxy? How do you choose in practice? 6. What are the differences among Squid, Varnish, and Nginx? How do you choose in practice? 7. What are the differences between Tomcat and Resin? How do you choose in practice? 8. What is middleware? What is JDK? 9. Explain the meanings of Tomcat ports 8005, 8009, and 8080. 10. What is a CDN? 11. What is gray‑scale release for a website? 12. Briefly describe the DNS domain resolution process. 13. What is RabbitMQ? 14. Explain the working principle of Keepalived. 15. Describe the three LVS modes and their processes. 16. How does MySQL InnoDB locate lock issues, and how can MySQL reduce master‑slave replication lag? 17. How to reset the MySQL root password? 18. Compare the advantages and disadvantages of LVS, Nginx, and HAProxy. 19. What tools are used for MySQL data backup? 20. Explain Keepalive’s working principle and how it performs health checks. 21. Analyze Nginx access logs to list the top ten IPs by page visits. 22. Use tcpdump to monitor traffic on host 192.168.1.1, port 80, and save output to tcpdump.log. 23. Forward local port 80 requests to port 8080 on host 192.168.2.1. 24. Describe the working principles and characteristics of RAID0, RAID1, and RAID5. 25. Share your understanding of the role and responsibilities of an operations engineer. 26. Write the complete command to capture and display real‑time TCP port 80 network data on the system. 27. How would you troubleshoot a server that fails to boot? 28. How to handle viruses on a Linux system? 29. If a virus file re‑creates itself after deletion, how would you resolve it? 30. Explain the seven layers of the TCP/IP model. 31. Which Nginx modules do you commonly use and for what purpose? 32. List the web server load‑balancing architectures you know. 33. How to view HTTP concurrent request numbers and their TCP connection states? 34. Use tcpdump to sniff port 80 traffic and identify the highest traffic source. 35. Write a script to determine which IPs in the 192.168.1.0/24 network are online (pingable). 36. Given Apache logs stored under /app/logs, how would you retain only the most recent 7 days of logs to save disk space? 37. How would you optimize a Linux system (general suggestions acceptable)? 38. Extract the IP address of eth0 using cut (optional: also using awk or sed). 39. Explain the function of the following SecureCRT shortcut keys. 40. Schedule a nightly backup at 12 am of /var/www/html to /data, creating a timestamped archive each time. 41. How to mount a Windows shared directory on Linux? 42. View HTTP concurrent request numbers and their TCP connection states. 43. Use tcpdump to sniff port 80 traffic and identify the highest traffic source. 44. Count the number of files under /var/log. 45. Show the number of connections per IP on the current system. 46. Generate a random 32‑bit password in a shell script. 47. List the top 5 IPs with the most accesses in Apache access.log.

1. Briefly describe ETCD and its characteristics. 2. What scenarios are suitable for ETCD? 3. Briefly explain what Kubernetes is. 4. Describe the relationship between Kubernetes and Docker. 5. What are Minikube, Kubectl, and Kubelet in Kubernetes? 6. List common deployment methods for Kubernetes. 7. How does Kubernetes achieve cluster management? What are its advantages, applicable scenarios, and characteristics? 8. What are the disadvantages or current limitations of Kubernetes? 9. Summarize basic concepts related to Kubernetes. 10. Describe the components of a Kubernetes cluster and the RC mechanism. 11. What is the role of kube‑proxy? 12. Explain the iptables and IPVS principles of kube‑proxy. 13. Compare the differences between kube‑proxy IPVS and iptables. 14. What is a static Pod in Kubernetes? 15. What states can a Pod be in? 16. Outline the main process of creating a Pod. 17. What are the restart policies for Pods? 18. How are health checks performed for Pods? 19. Common ways to implement LivenessProbe for Pods? 20. Typical scheduling strategies for Pods? 21. What is an init container? 22. Describe the upgrade process for a Deployment. 23. What are the upgrade strategies for Deployments? 24. Characteristics of DaemonSet resources? 25. How does Kubernetes achieve auto‑scaling? 26. Types of Kubernetes Services? 27. Backend distribution strategies for Services? 28. What is a Headless Service? 29. How can external clients access services inside a cluster? 30. Explain the concept of Ingress. 31. Describe image download strategies for Kubernetes. 32. How does Kubernetes implement load balancing? 33. How do various modules communicate with the API Server? 34. Role and implementation principle of the Scheduler. 35. Which two algorithms does the Scheduler use to bind Pods to worker nodes? 36. What is the function of kubelet? 37. Which component does kubelet use to monitor worker node resources? 38. How does Kubernetes ensure cluster security? 39. What is the admission control mechanism? 40. Describe RBAC in Kubernetes and its advantages. 41. What is the purpose of a Secret? 42. How can Secrets be used? 43. Explain the PodSecurityPolicy mechanism and the security strategies it can enforce. 44. Summarize the Kubernetes networking model. 45. What is the CNI model in Kubernetes? 46. Describe Kubernetes network policies and their principles. 47. What is the role of flannel? 48. Explain the implementation principle of Calico. 49. What is the purpose of shared storage in Kubernetes? 50. List the ways Kubernetes handles data persistence, including PV and PVC.