How to Troubleshoot Common HPC Cluster Issues

Troubleshooting an HPC cluster requires a systematic approach to quickly identify and resolve issues. Here is a practical guide:

Step 1: Identify the Problem

• Clearly define the symptoms: Job failures, slow performance, node downtime.
• Check logs for errors (system logs, scheduler logs, application logs).

Step 2: Network Issues

• Test network connectivity with ping and traceroute.
• ping <node>
• traceroute <node>
• Check switch status and network interface configurations.

Step 3: Job Scheduler Issues

• Verify scheduler status:
• scontrol show nodes
• squeue
• Check scheduler logs for errors or warnings:
• less /var/log/slurm/slurmctld.log

Step 4: Node Health Issues

• Confirm node status with monitoring tools (Ganglia, Nagios).
• Check hardware status using IPMI or vendor-specific utilities.

Step 5: MPI Job Failures

• Ensure MPI libraries are installed consistently across nodes.
• Check MPI environment:
• mpirun --version
• mpirun -np 4 hostname

Step 6: Performance Issues

• Identify resource bottlenecks using tools like top, htop, and vmstat.
• Monitor disk performance with iostat and network performance with iftop.

Step 7: File System Issues

• Check storage space and permissions:
• df -h
• ls -l /path/to/directory
• Verify the status of shared file systems (Lustre, BeeGFS, NFS).

Step 8: Software Issues

• Confirm software versions and module configurations.
• Reinstall or update problematic software components if needed.

Step 9: Document and Prevent

• Record issues, resolutions, and relevant logs.
• Implement monitoring alerts and preventive maintenance routines.

Following these structured troubleshooting steps will help quickly pinpoint and resolve common HPC cluster issues, minimizing downtime and maximizing cluster efficiency.