memory-profiling

name	memory-profiling
description	Go application memory profiling and analysis. Use when investigating memory leaks or high memory usage.
disable-model-invocation	true
user-invocable	true
allowed-tools	Bash, Read, Grep

Memory Profiling Skill

Investigate and analyze Go application memory usage through heap profiling and comparative analysis.

Prerequisites

IMPORTANT: pprof server requires KATTLE_DEBUG=1 environment variable:

# Start the application with debug mode enabled
KATTLE_DEBUG=1 wails dev

Verify pprof server is running:

curl -s http://localhost:6060/debug/pprof/ > /dev/null && echo "pprof OK" || echo "pprof NOT available"

Current State Check

Before profiling, establish the current memory baseline:

ps aux | grep -E "(PID|kattle|gui)" | head -20

Verify baseline profile exists (from project root):

ls -lh baseline_heap.pb.gz 2>/dev/null || echo "No baseline found"

Heap Profile Collection

Collect a heap profile from the running application:

curl -o /tmp/heap.pb.gz http://localhost:6060/debug/pprof/heap

Verify collection was successful:

ls -lh /tmp/heap.pb.gz

Alternative: The app provides DumpMemory(label) function which saves labeled dumps to ~/kattle-dumps/:

• Format: heap_<timestamp>_<seq>_<label>.pb.gz
• Location: ~/kattle-dumps/

Analysis Commands

Top 10 Memory Allocators

Get the most significant memory allocators:

go tool pprof -top /tmp/heap.pb.gz | head -15

Differential Analysis (vs Baseline)

Compare current heap profile against a known baseline:

go tool pprof -diff_base=baseline_heap.pb.gz -top /tmp/heap.pb.gz

Or use the helper script:

bash /Users/hansuk.hong/P/kattle/.claude/skills/memory-profiling/scripts/compare-heap.sh [baseline_path] [current_path]

Interactive Investigation

For deeper analysis, use interactive mode:

go tool pprof /tmp/heap.pb.gz
# Then use commands like: top, list <function>, alloc_space, alloc_objects

Reporting Format

When analyzing memory profiles, report:

1. Top 10 Allocators: List of functions responsible for largest allocations
2. Delta from Baseline: Increase/decrease in allocation patterns since baseline
3. Suspect Areas: Functions or packages with unexplained growth
4. Memory Metrics:
   • Total inuse_space (bytes)
   • Total alloc_objects (count)
   • Per-function percentages of total heap

Example Report Structure

Memory Profile Analysis Report
==============================

Top 10 Allocators (Current):
1. package.function - X.XGB (XX%)
2. package.function - X.XGB (XX%)
...

Changes vs Baseline:
- package.function: +X.XGB (new allocation)
- package.function: -X.XGB (reduction)

Suspect Areas:
- package.function: Excessive allocation growth
- Recommendations for investigation

Usage Workflow

1. Establish baseline: Collect heap profile when application is in healthy state
2. Run application under load or over time
3. Collect current heap profile
4. Compare using differential analysis
5. Investigate top allocators and changes
6. Identify memory leaks or optimization opportunities