Managing the Backend

The ncprof backend manages the logic related to processing traces and registering tracepoints. This page details the various commands available to start, stop and check status of the backend.

Managing the Backend

All backend commands are accessed via Command Palette (Ctrl+Shift+P / Cmd+Shift+P):

• Start: NCProf: Start Profiler Backend (Docker)
  • First start: Docker images pull (a few minutes), creates .cache/ncompass/ directory
  • Subsequent starts: Much faster (images cached)
• Stop: NCProf: Stop Profiler Backend (preserves data in .cache/ncompass/)
• Restart: NCProf: Restart Profiler Backend (equivalent to stop + start)
• Status: NCProf: Check NCProf Backend Status (shows container status)

Healthy backend status:

NAME                    STATUS
nc-ncprof-redis         Up 2 minutes
nc-ncprof-server        Up 2 minutes (healthy)
nc-ncprof-register      Up 2 minutes (healthy)

Auto-Start Configuration

Enable automatic backend startup when opening VS Code:

• Settings UI: Open Settings (Ctrl+,) → Search “ncprof backend” → Check ncprof.backend.autoStart
• settings.json: Add "ncprof.backend.autoStart": true

Understanding the Cache Directory

Location and Structure

The backend stores data in your workspace:

<workspace>/.cache/ncompass/
├── profiles/              # Profile configurations
│   └── .default/          # Default profile
│       └── .default/
│           ├── current/   # Symlink to latest session
│           │   └── config.json
│           ├── 20240101_120000_000000/  # Timestamped session 1
│           │   └── config.json
│           └── 20240102_130000_000000/  # Timestamped session 2
│               └── config.json
└── (other cache data)

What’s Stored

• Profile configurations: Generated config.json files with instrumentation details
• Session history: Timestamped directories for each profiling session
• Current symlink: Points to the most recent configuration

Next Steps

• Settings & Commands: Complete reference of backend-related settings
• Detailed breakdown of profiling workflow: Learn how to use the backend for profiling