Memory Capture Skill

This skill provides tools for capturing memory profile snapshots and comparing them against baseline profiles to verify memory optimization efforts.

Prerequisites

IMPORTANT: pprof server requires KATTLE_DEBUG=1 environment variable:

bash

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

Verify pprof server is running:

bash

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

Note: Run all commands from project root directory where baseline_heap.pb.gz and baseline_goroutine.txt are located.

Capabilities

1. Heap Profile Capture

Captures the current heap memory profile:

bash

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

This generates a compressed protobuf format heap profile that can be analyzed with go tool pprof.

2. Goroutine Profile Capture

Captures the current goroutine information:

bash

curl -s http://localhost:6060/debug/pprof/goroutine?debug=1 > /tmp/current_goroutine.txt

This captures goroutine stack traces in text format for easy inspection.

3. Compare with Baseline

Heap Comparison

Compare current heap profile against baseline using pprof's diff mode:

bash

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

This shows the differences in memory allocation between the baseline and current profiles.

Goroutine Count Comparison

Extract and compare actual goroutine counts (not line counts):

bash

# Extract goroutine count from first line "goroutine N [...]"
head -1 baseline_goroutine.txt | grep -oE 'goroutine [0-9]+' | cut -d' ' -f2
head -1 /tmp/current_goroutine.txt | grep -oE 'goroutine [0-9]+' | cut -d' ' -f2

Or count total goroutines in the profile:

bash

grep -c '^goroutine' baseline_goroutine.txt
grep -c '^goroutine' /tmp/current_goroutine.txt

4. Update Baseline (if improved)

When optimization is verified and improvements are confirmed:

bash

cp /tmp/current_heap.pb.gz baseline_heap.pb.gz
cp /tmp/current_goroutine.txt baseline_goroutine.txt

This updates the baseline profiles for future comparisons.

Usage

Use the provided capture-profile.sh script to capture both profiles in one command:

bash

./scripts/capture-profile.sh [PORT]

Default port is 6060 if not specified.

Workflow

•Capture baseline profiles before optimization
•Implement memory optimizations
•Capture new profiles after optimization
•Compare using the tools above
•If improvements verified, update baseline
•Continue iterating or celebrate success