Logging strategies in HLD - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Log Levels

Which log level is most appropriate for recording detailed information useful for diagnosing problems during development but too verbose for production?

A DEBUG

B INFO

C WARN

D ERROR

💡 Hint

Think about the level that provides the most detailed information for developers.

DEBUG level logs provide detailed diagnostic information useful during development but are usually turned off in production to reduce noise.

💻 Command Output

intermediate

Log Rotation Command Output

What is the output of running the command logrotate -d /etc/logrotate.conf on a Linux system?

HLD

logrotate -d /etc/logrotate.conf

A Starts the logrotate daemon in debug mode

B Rotates logs immediately and deletes old logs

C Shows syntax errors in the logrotate configuration file

D Simulates log rotation and shows what would be done without making changes

💡 Hint

The -d flag is for debug mode without actual changes.

The -d option runs logrotate in debug mode, showing what actions would be taken without performing them.

❓ Configuration

advanced

Configuring Centralized Logging

Which configuration snippet correctly sets up a syslog client to forward all logs to a remote server at 192.168.1.100 on UDP port 514?

A *.* 192.168.1.100:514

B *.* @@192.168.1.100:514

C *.* @192.168.1.100:514

D *.* :192.168.1.100:514

💡 Hint

Single '@' means UDP, double '@@' means TCP in syslog forwarding.

In syslog configuration, *.* @192.168.1.100:514 forwards all logs via UDP to the remote server.

❓ Troubleshoot

advanced

Troubleshooting Missing Logs

A developer notices that application logs are missing after configuring a new logging agent. Which of the following is the most likely cause?

A The logging agent is running but lacks permission to read the log files

B The application is not generating any logs

C The logging agent is configured to write logs locally instead of forwarding

D The system clock is set incorrectly

💡 Hint

Check file permissions for the logging agent.

If the logging agent cannot read log files due to permission issues, it will not forward logs even if running.

✅ Best Practice

expert

Best Practice for Log Retention Policy

What is the best practice for setting a log retention policy in a production environment to balance storage use and compliance?

A Delete logs immediately after processing to save space

B Retain logs for a defined period based on compliance requirements, then archive or delete

C Keep all logs indefinitely to ensure full audit trail

D Only keep error logs and discard info and debug logs

💡 Hint

Consider legal and operational needs when deciding retention time.

Balancing storage and compliance means keeping logs long enough to meet requirements, then archiving or deleting them.