4.5 Troubleshooting Issues PROFESSIONAL-CLOUD-DEVOPS-ENGINEER Practice Questions (Page 6)

Questions 26–30

1. 26foundation · easy

   A DevOps engineer is troubleshooting a Compute Engine VM that fails to start. Which systematic approach should be used first?

   • ACheck the VM's serial console output and boot logs for errors.
   • BOpen a support case with Google Cloud without any investigation.
   • CChange the VM's machine type to a larger size.
   • DImmediately delete and recreate the VM with the same configuration.
   Reveal Solution Discussion Select an answer first
2. 27application · medium

   An application's response time has degraded. You are looking at a trace of a single request. The trace shows the following spans: 'Frontend Service' (50 ms), 'Authentication Service' (200 ms), and 'Database Query' (1.5 s). The database is a Cloud SQL instance. The CPU utilization on the Cloud SQL instance is at 90%. What is the most likely bottleneck?

   • AThe network between the application and Cloud SQL is congested, causing packet loss.
   • BThe database query is slow because the Cloud SQL instance is CPU-bound.
   • CThe frontend service is slow because it is rendering a large HTML page.
   • DThe authentication service is slow because it is making a synchronous call to the database.
   Reveal Solution Discussion Select an answer first
4. 28application · medium

   Users report that a web application is slow. You look at Cloud Monitoring and see that the p95 latency for the application's main endpoint has increased from 200 ms to 2 seconds. The CPU and memory utilization on the backend VMs are normal. The trace data shows that the application spends 1.8 seconds waiting on a call to a third-party payment API. What is the most effective immediate action?

   • AScale out the backend VMs to handle more concurrent requests.
   • BInvestigate the payment API's performance and check if there is a known outage or increased latency on their side.
   • CIncrease the timeout for the payment API call in the application configuration.
   • DEnable response compression in the application to reduce the payload size and speed up the response.
   Reveal Solution Discussion Select an answer first
5. 29foundation · easy

   A CI/CD pipeline fails because the deployment step cannot access a Cloud Storage bucket. Which configuration should be checked first?

   • AThe source code repository's branch protection rules
   • BThe Cloud Monitoring alerting policies
   • CThe pipeline's build triggers
   • DThe IAM permissions of the service account used by the pipeline
   Reveal Solution Discussion Select an answer first
6. 30application · medium

   A web server on a Compute Engine VM is not responding to HTTP requests from the internet. You can SSH into the VM and see that the web server process (e.g., nginx) is running and listening on port 80. You have verified that the VM has a public IP address. What is the most likely cause?

   • AThe web server is configured to listen on a different port, such as 8080.
   • BThe VM's public IP address has changed, and the DNS record is pointing to the old IP.
   • CThe VM's operating system firewall (e.g., iptables) is blocking incoming connections on port 80.
   • DA VPC firewall rule is blocking ingress traffic on port 80 from the internet.
   Reveal Solution Discussion Select an answer first