Memory Usage Monitor - Hooks

Features

• Real-time memory usage monitoring across multiple programming languages with process-specific memory tracking for Node.js (node processes), Python (python processes), Java (java processes), Ruby (ruby processes), PHP (php processes), Go (go processes), Rust (rust processes), .NET (dotnet processes), and development tools (VS Code, Claude) with pgrep for accurate process detection and memory aggregation
• Process-specific memory tracking for Node.js, Python, Java, and Ruby with pgrep -f for process pattern matching, /proc/pid/status (Linux) or ps -o rss (macOS) for memory reading, VmRSS (Resident Set Size) for Linux process memory, RSS (Resident Set Size) for macOS process memory, and process memory aggregation with total memory calculation
• Configurable memory threshold alerts and warnings with high memory threshold (default 75%, configurable via HIGH_MEMORY_THRESHOLD), critical memory threshold (default 90%, configurable via CRITICAL_MEMORY_THRESHOLD), high swap threshold (default 25%, configurable via HIGH_SWAP_THRESHOLD), threshold-based alerting with ERROR/WARNING/INFO levels, and actionable recommendations based on thresholds
• Swap usage monitoring and excessive swap detection with swap usage percentage calculation (SWAP_USED_KB * 100 / SWAP_TOTAL_KB), swap total/used tracking from /proc/swaps (Linux) or sysctl vm.swapusage (macOS), excessive swap warnings when swap usage exceeds threshold, and swap configuration detection (swap not configured reporting)
• Memory leak detection with historical usage tracking including process memory accumulation detection (monitoring process memory over time), development process memory percentage calculation (TOTAL_DEV_MEMORY_KB * 100 / TOTAL_MEMORY_KB), memory leak warnings when dev processes use >50% of system memory, and process count tracking for memory leak indicators
• Container memory monitoring for Docker environments with Docker container memory stats using docker stats --no-stream, running container count detection (docker ps), container memory usage reporting with top container memory usage, Docker availability checking, and container memory recommendations
• Cross-platform memory monitoring (Linux, macOS, Windows) with platform-specific memory detection including /proc/meminfo for Linux (MemTotal, MemAvailable, MemFree, Buffers, Cached), vm_stat for macOS (Pages free, Pages active, Pages inactive, Pages wired), fallback methods for unsupported platforms, and page size calculation for macOS (4096 bytes Intel, 16384 bytes Apple Silicon)
• Memory pressure analysis and system health reporting with memory usage summaries including total/used memory with percentages, swap usage reporting, development process memory reporting, process counts, warning/error counts, status indicators (OPTIMAL, GOOD, CRITICAL), and actionable recommendations with best practices

Use Cases

• Development environment performance optimization and monitoring automatically monitoring memory usage during development, detecting high memory usage, and providing recommendations for memory optimization for efficient development workflows
• Memory leak detection and prevention in long-running development sessions automatically detecting memory leaks in development processes, tracking memory accumulation, and alerting when memory usage exceeds thresholds for reliable long-running development sessions
• System resource management and capacity planning automatically monitoring system memory usage, tracking memory trends, and providing capacity planning insights for efficient resource management
• Container and microservices memory monitoring automatically monitoring Docker container memory usage, detecting container memory issues, and providing container memory recommendations for reliable containerized development
• CI/CD pipeline resource usage tracking and optimization automatically monitoring memory usage in CI/CD pipelines, detecting resource constraints, and optimizing pipeline resource usage for efficient CI/CD operations
• Development workflow integration seamlessly integrating memory monitoring into development workflows without manual monitoring steps or separate monitoring tools

Installation

1. Create hooks directory: mkdir -p .claude/hooks
2. Create hook file: touch .claude/hooks/memory-usage-monitor.sh
3. Make executable: chmod +x .claude/hooks/memory-usage-monitor.sh
4. Add configuration from Hook Configuration section above to .claude/settings.json or ~/.claude/settings.json
5. Alternative: Use the interactive /hooks command in Claude Code

Config paths

• Local (not committed): .claude/settings.local.json
• User settings (global): ~/.claude/settings.json
• Project-wide (committed): .claude/settings.json

Requirements

• Claude Code CLI installed
• Project directory initialized
• Bash shell available
• pgrep (optional, for process detection)
• docker (optional, for container monitoring)
• sysctl (optional, for macOS swap monitoring)

Hook Configuration

{
  "hooks": {
    "notification": {
      "script": "./.claude/hooks/memory-usage-monitor.sh",
      "timeout": 5000
    }
  }
}

Hook Script

#!/usr/bin/env bash

# Memory Usage Monitor Hook
# Monitors system and process memory usage during development activities

echo "💾 Memory Usage Monitor" >&2

# Initialize monitoring variables
TOTAL_MEMORY_KB=0
USED_MEMORY_KB=0
MEMORY_PERCENT=0
SWAP_PERCENT=0
HIGH_MEMORY_THRESHOLD=75
CRITICAL_MEMORY_THRESHOLD=90
HIGH_SWAP_THRESHOLD=25
WARNINGS=0
ERRORS=0

# Function to report memory status
report_memory() {
  local level="$1"
  local message="$2"

  case "$level" in
    "ERROR")
      echo "❌ CRITICAL: $message" >&2
      ERRORS=$((ERRORS + 1))
      ;;
    "WARNING")
      echo "⚠️ WARNING: $message" >&2
      WARNINGS=$((WARNINGS + 1))
      ;;
    "INFO")
      echo "ℹ️ INFO: $message" >&2
      ;;
    "PASS")
      echo "✅ OK: $message" >&2
      ;;
  esac
}

# Function to format bytes to human readable
format_bytes() {
  local bytes=$1
  local units=("B" "KB" "MB" "GB" "TB")
  local unit=0

  while (( bytes > 1024 && unit < 4 )); do
    bytes=$((bytes / 1024))
    unit=$((unit + 1))
  done

  echo "${bytes}${units[$unit]}"
}

# 1. System Memory Analysis
echo "📊 Analyzing system memory usage..." >&2

# Detect operating system for platform-specific commands
OS_TYPE=$(uname -s)

case "$OS_TYPE" in
  "Linux")
    # Linux memory information
    if [ -f /proc/meminfo ]; then
      TOTAL_MEMORY_KB=$(grep '^MemTotal:' /proc/meminfo | awk '{print $2}')
      AVAILABLE_MEMORY_KB=$(grep '^MemAvailable:' /proc/meminfo | awk '{print $2}' || echo "0")

      if [ "$AVAILABLE_MEMORY_KB" -eq 0 ]; then
        # Fallback calculation for older systems
        FREE_MEMORY_KB=$(grep '^MemFree:' /proc/meminfo | awk '{print $2}')
        BUFFERS_KB=$(grep '^Buffers:' /proc/meminfo | awk '{print $2}')
        CACHED_KB=$(grep '^Cached:' /proc/meminfo | awk '{print $2}')
        AVAILABLE_MEMORY_KB=$((FREE_MEMORY_KB + BUFFERS_KB + CACHED_KB))
      fi

      USED_MEMORY_KB=$((TOTAL_MEMORY_KB - AVAILABLE_MEMORY_KB))
      MEMORY_PERCENT=$((USED_MEMORY_KB * 100 / TOTAL_MEMORY_KB))

      echo "   🖥️ Total Memory: $(format_bytes $((TOTAL_MEMORY_KB * 1024)))" >&2
      echo "   📈 Used Memory: $(format_bytes $((USED_MEMORY_KB * 1024))) ($MEMORY_PERCENT%)" >&2

      # Check swap usage
      if [ -f /proc/swaps ]; then
        SWAP_TOTAL_KB=$(awk 'NR>1 {sum+=$3} END {print sum+0}' /proc/swaps)
        SWAP_USED_KB=$(awk 'NR>1 {sum+=$4} END {print sum+0}' /proc/swaps)

        if [ "$SWAP_TOTAL_KB" -gt 0 ]; then
          SWAP_PERCENT=$((SWAP_USED_KB * 100 / SWAP_TOTAL_KB))
          echo "   💿 Swap Usage: $(format_bytes $((SWAP_USED_KB * 1024))) / $(format_bytes $((SWAP_TOTAL_KB * 1024))) ($SWAP_PERCENT%)" >&2
        else
          echo "   💿 Swap: Not configured" >&2
        fi
      fi
    else
      report_memory "WARNING" "Unable to read /proc/meminfo - memory monitoring limited"
    fi
    ;;

  "Darwin")
    # macOS memory information
    if command -v vm_stat &> /dev/null; then
      # Get page size
      PAGE_SIZE=$(vm_stat | grep 'page size of' | awk '{print $8}' || echo "4096")

      # Get memory statistics
      VM_STAT_OUTPUT=$(vm_stat)
      PAGES_FREE=$(echo "$VM_STAT_OUTPUT" | grep 'Pages free:' | awk '{print $3}' | tr -d '.')
      PAGES_ACTIVE=$(echo "$VM_STAT_OUTPUT" | grep 'Pages active:' | awk '{print $3}' | tr -d '.')
      PAGES_INACTIVE=$(echo "$VM_STAT_OUTPUT" | grep 'Pages inactive:' | awk '{print $3}' | tr -d '.')
      PAGES_SPECULATIVE=$(echo "$VM_STAT_OUTPUT" | grep 'Pages speculative:' | awk '{print $3}' | tr -d '.' || echo "0")
      PAGES_WIRED=$(echo "$VM_STAT_OUTPUT" | grep 'Pages wired down:' | awk '{print $4}' | tr -d '.')

      # Calculate memory usage
      TOTAL_PAGES=$((PAGES_FREE + PAGES_ACTIVE + PAGES_INACTIVE + PAGES_SPECULATIVE + PAGES_WIRED))
      USED_PAGES=$((PAGES_ACTIVE + PAGES_INACTIVE + PAGES_SPECULATIVE + PAGES_WIRED))
      TOTAL_MEMORY_KB=$((TOTAL_PAGES * PAGE_SIZE / 1024))
      USED_MEMORY_KB=$((USED_PAGES * PAGE_SIZE / 1024))
      MEMORY_PERCENT=$((USED_MEMORY_KB * 100 / TOTAL_MEMORY_KB))

      echo "   🖥️ Total Memory: $(format_bytes $((TOTAL_MEMORY_KB * 1024)))" >&2
      echo "   📈 Used Memory: $(format_bytes $((USED_MEMORY_KB * 1024))) ($MEMORY_PERCENT%)" >&2

      # Check swap usage on macOS
      if command -v sysctl &> /dev/null; then
        SWAP_USAGE=$(sysctl vm.swapusage 2>/dev/null | grep -oE 'used = [0-9.]+[KMGT]?' | awk '{print $3}' || echo "0")
        SWAP_TOTAL=$(sysctl vm.swapusage 2>/dev/null | grep -oE 'total = [0-9.]+[KMGT]?' | awk '{print $3}' || echo "0")
        echo "   💿 Swap Usage: $SWAP_USAGE / $SWAP_TOTAL" >&2
      fi
    else
      report_memory "WARNING" "vm_stat command not available - memory monitoring limited"
    fi
    ;;

  *)
    report_memory "WARNING" "Unsupported operating system ($OS_TYPE) - limited memory monitoring"
    ;;
esac

# 2. Process-Specific Memory Analysis
echo "🔍 Analyzing development process memory usage..." >&2

# Define process patterns for different development environments
DEV_PROCESSES=("node" "python" "java" "ruby" "php" "go" "rust" "dotnet" "code" "claude")
TOTAL_DEV_MEMORY_KB=0
PROCESS_COUNT=0

for process in "${DEV_PROCESSES[@]}"; do
  if command -v pgrep &> /dev/null; then
    # Use pgrep for more accurate process detection
    PIDS=$(pgrep -f "$process" 2>/dev/null || true)

    if [ -n "$PIDS" ]; then
      PROCESS_MEMORY=0
      PROC_COUNT=0

      # Calculate memory for all matching processes
      for pid in $PIDS; do
        if [ -f "/proc/$pid/status" ]; then
          # Linux: Read from /proc/pid/status
          PID_MEMORY=$(grep '^VmRSS:' "/proc/$pid/status" 2>/dev/null | awk '{print $2}' || echo "0")
        elif command -v ps &> /dev/null; then
          # macOS/Other: Use ps command
          PID_MEMORY=$(ps -o rss= -p "$pid" 2>/dev/null | awk '{print $1}' || echo "0")
        else
          PID_MEMORY=0
        fi

        PROCESS_MEMORY=$((PROCESS_MEMORY + PID_MEMORY))
        PROC_COUNT=$((PROC_COUNT + 1))
      done

      if [ "$PROCESS_MEMORY" -gt 0 ]; then
        echo "   🔧 $process processes: $PROC_COUNT running, $(format_bytes $((PROCESS_MEMORY * 1024))) memory" >&2
        TOTAL_DEV_MEMORY_KB=$((TOTAL_DEV_MEMORY_KB + PROCESS_MEMORY))
        PROCESS_COUNT=$((PROCESS_COUNT + PROC_COUNT))
      fi
    fi
  fi
done

if [ "$TOTAL_DEV_MEMORY_KB" -gt 0 ]; then
  DEV_MEMORY_PERCENT=$((TOTAL_DEV_MEMORY_KB * 100 / TOTAL_MEMORY_KB))
  echo "   📊 Total dev processes: $PROCESS_COUNT processes, $(format_bytes $((TOTAL_DEV_MEMORY_KB * 1024))) ($DEV_MEMORY_PERCENT% of system)" >&2
else
  echo "   📋 No development processes detected" >&2
fi

# 3. Container Memory Monitoring (if applicable)
echo "🐳 Checking container memory usage..." >&2

if command -v docker &> /dev/null && docker info >/dev/null 2>&1; then
  # Check Docker container memory usage
  RUNNING_CONTAINERS=$(docker ps --format "table {{.Names}}" --no-trunc 2>/dev/null | tail -n +2 | wc -l || echo "0")

  if [ "$RUNNING_CONTAINERS" -gt 0 ]; then
    echo "   🐳 Docker containers: $RUNNING_CONTAINERS running" >&2

    # Get container memory stats (basic)
    CONTAINER_STATS=$(docker stats --no-stream --format "table {{.Container}}\t{{.MemUsage}}" 2>/dev/null | tail -n +2 | head -5 || true)

    if [ -n "$CONTAINER_STATS" ]; then
      echo "   📊 Top container memory usage:" >&2
      echo "$CONTAINER_STATS" | while read line; do
        echo "     $line" >&2
      done
    fi
  else
    echo "   🐳 No running Docker containers" >&2
  fi
else
  echo "   🐳 Docker not available or not running" >&2
fi

# 4. Memory Threshold Analysis
echo "⚠️ Analyzing memory thresholds..." >&2

# Check system memory thresholds
if [ "$MEMORY_PERCENT" -ge "$CRITICAL_MEMORY_THRESHOLD" ]; then
  report_memory "ERROR" "Critical system memory usage: $MEMORY_PERCENT% (threshold: $CRITICAL_MEMORY_THRESHOLD%)"
elif [ "$MEMORY_PERCENT" -ge "$HIGH_MEMORY_THRESHOLD" ]; then
  report_memory "WARNING" "High system memory usage: $MEMORY_PERCENT% (threshold: $HIGH_MEMORY_THRESHOLD%)"
else
  report_memory "PASS" "System memory usage within normal range: $MEMORY_PERCENT%"
fi

# Check swap usage
if [ "$SWAP_PERCENT" -ge "$HIGH_SWAP_THRESHOLD" ]; then
  report_memory "WARNING" "High swap usage detected: $SWAP_PERCENT% (threshold: $HIGH_SWAP_THRESHOLD%)"
else
  if [ "$SWAP_PERCENT" -gt 0 ]; then
    report_memory "INFO" "Swap usage normal: $SWAP_PERCENT%"
  fi
fi

# Check for potential memory leaks (high dev process usage)
if [ "$TOTAL_DEV_MEMORY_KB" -gt 0 ] && [ "$DEV_MEMORY_PERCENT" -ge 50 ]; then
  report_memory "WARNING" "Development processes using significant memory: $DEV_MEMORY_PERCENT% of system"
elif [ "$TOTAL_DEV_MEMORY_KB" -gt 0 ]; then
  report_memory "INFO" "Development process memory usage normal: $DEV_MEMORY_PERCENT% of system"
fi

# 5. Memory Recommendations
echo "💡 Memory optimization recommendations..." >&2

if [ "$MEMORY_PERCENT" -ge "$HIGH_MEMORY_THRESHOLD" ]; then
  echo "   • Consider closing unused applications and browser tabs" >&2
  echo "   • Restart development servers to free up memory" >&2
  echo "   • Check for memory leaks in your applications" >&2
fi

if [ "$SWAP_PERCENT" -ge "$HIGH_SWAP_THRESHOLD" ]; then
  echo "   • High swap usage may slow down development" >&2
  echo "   • Consider adding more RAM or closing applications" >&2
fi

if [ "$PROCESS_COUNT" -gt 10 ]; then
  echo "   • Many development processes running ($PROCESS_COUNT)" >&2
  echo "   • Consider stopping unused development servers" >&2
fi

# 6. Generate Memory Summary
echo "" >&2
echo "📋 Memory Usage Summary:" >&2
echo "========================" >&2
echo "   💾 System Memory: $MEMORY_PERCENT% used ($(format_bytes $((USED_MEMORY_KB * 1024))) / $(format_bytes $((TOTAL_MEMORY_KB * 1024))))" >&2
[ "$SWAP_PERCENT" -gt 0 ] && echo "   💿 Swap Usage: $SWAP_PERCENT%" >&2
echo "   🔧 Dev Processes: $PROCESS_COUNT running ($(format_bytes $((TOTAL_DEV_MEMORY_KB * 1024))))" >&2
echo "   ⚠️ Warnings: $WARNINGS" >&2
echo "   ❌ Critical Issues: $ERRORS" >&2

if [ "$ERRORS" -eq 0 ] && [ "$WARNINGS" -eq 0 ]; then
  echo "   🎉 Status: OPTIMAL - Memory usage is healthy" >&2
elif [ "$ERRORS" -eq 0 ]; then
  echo "   ✅ Status: GOOD - Memory usage acceptable with minor warnings" >&2
else
  echo "   ❌ Status: CRITICAL - Memory usage requires immediate attention" >&2
fi

echo "" >&2
echo "💡 Memory Best Practices:" >&2
echo "   • Monitor memory usage regularly during development" >&2
echo "   • Use memory profiling tools to identify leaks" >&2
echo "   • Restart development servers periodically" >&2
echo "   • Consider using lighter development tools when memory is limited" >&2
echo "   • Close unused applications and browser tabs" >&2

# Memory monitoring complete
exit 0

Examples

Memory Usage Monitor Hook Script

Complete hook script that performs memory usage monitoring

#!/usr/bin/env bash
echo "💾 Memory Usage Monitor" >&2
OS_TYPE=$(uname -s)
if [ "$OS_TYPE" = "Linux" ] && [ -f /proc/meminfo ]; then
  TOTAL_MEMORY_KB=$(grep '^MemTotal:' /proc/meminfo | awk '{print $2}')
  AVAILABLE_MEMORY_KB=$(grep '^MemAvailable:' /proc/meminfo | awk '{print $2}' || echo "0")
  USED_MEMORY_KB=$((TOTAL_MEMORY_KB - AVAILABLE_MEMORY_KB))
  MEMORY_PERCENT=$((USED_MEMORY_KB * 100 / TOTAL_MEMORY_KB))
  echo "📊 Memory Usage: $MEMORY_PERCENT%" >&2
  if [ "$MEMORY_PERCENT" -ge 90 ]; then
    echo "❌ CRITICAL: Memory usage exceeds 90%" >&2
  elif [ "$MEMORY_PERCENT" -ge 75 ]; then
    echo "⚠️ WARNING: High memory usage" >&2
  fi
fi
exit 0

Process-Specific Memory Tracking

Enhanced hook script for tracking development process memory usage

#!/usr/bin/env bash
OS_TYPE=$(uname -s)
DEV_PROCESSES=("node" "python" "java" "ruby")
TOTAL_DEV_MEMORY_KB=0
for process in "${DEV_PROCESSES[@]}"; do
  if command -v pgrep &> /dev/null; then
    PIDS=$(pgrep -u $USER -f "$process" 2>/dev/null || true)
    for pid in $PIDS; do
      if [ "$OS_TYPE" = "Linux" ] && [ -f "/proc/$pid/status" ]; then
        PID_MEMORY=$(grep '^VmRSS:' "/proc/$pid/status" 2>/dev/null | awk '{print $2}' || echo "0")
      elif command -v ps &> /dev/null; then
        PID_MEMORY=$(ps -o rss= -p "$pid" 2>/dev/null | awk '{print $1}' || echo "0")
      fi
      TOTAL_DEV_MEMORY_KB=$((TOTAL_DEV_MEMORY_KB + PID_MEMORY))
    done
  fi
done
echo "🔧 Development processes: $(($TOTAL_DEV_MEMORY_KB / 1024))MB" >&2
exit 0

Container Memory Monitoring

Enhanced hook script for Docker container memory monitoring

#!/usr/bin/env bash
if command -v docker &> /dev/null && docker info >/dev/null 2>&1; then
  RUNNING_CONTAINERS=$(docker ps --format "table {{.Names}}" --no-trunc 2>/dev/null | tail -n +2 | wc -l || echo "0")
  if [ "$RUNNING_CONTAINERS" -gt 0 ]; then
    echo "🐳 Docker containers: $RUNNING_CONTAINERS running" >&2
    CONTAINER_STATS=$(timeout 5 docker stats --no-stream --format "table {{.Container}}\t{{.MemUsage}}" 2>/dev/null | tail -n +2 | head -5 || true)
    if [ -n "$CONTAINER_STATS" ]; then
      echo "📊 Top container memory usage:" >&2
      echo "$CONTAINER_STATS" | while read line; do
        echo "  $line" >&2
      done
    fi
  fi
fi
exit 0

macOS Memory Monitoring

Enhanced hook script for macOS memory monitoring with Apple Silicon support

#!/usr/bin/env bash
OS_TYPE=$(uname -s)
if [ "$OS_TYPE" = "Darwin" ] && command -v vm_stat &> /dev/null; then
  PAGE_SIZE=4096
  if [ "$(uname -m)" = "arm64" ]; then
    PAGE_SIZE=16384
  fi
  VM_STAT_OUTPUT=$(vm_stat)
  PAGES_FREE=$(echo "$VM_STAT_OUTPUT" | grep 'Pages free:' | awk '{print $3}' | tr -d '.')
  PAGES_ACTIVE=$(echo "$VM_STAT_OUTPUT" | grep 'Pages active:' | awk '{print $3}' | tr -d '.')
  PAGES_INACTIVE=$(echo "$VM_STAT_OUTPUT" | grep 'Pages inactive:' | awk '{print $3}' | tr -d '.')
  PAGES_WIRED=$(echo "$VM_STAT_OUTPUT" | grep 'Pages wired down:' | awk '{print $4}' | tr -d '.')
  TOTAL_PAGES=$((PAGES_FREE + PAGES_ACTIVE + PAGES_INACTIVE + PAGES_WIRED))
  USED_PAGES=$((PAGES_ACTIVE + PAGES_INACTIVE + PAGES_WIRED))
  TOTAL_MEMORY_KB=$((TOTAL_PAGES * PAGE_SIZE / 1024))
  USED_MEMORY_KB=$((USED_PAGES * PAGE_SIZE / 1024))
  MEMORY_PERCENT=$((USED_MEMORY_KB * 100 / TOTAL_MEMORY_KB))
  echo "📊 macOS Memory Usage: $MEMORY_PERCENT%" >&2
fi
exit 0

Troubleshooting

Memory percentage calculation shows values over 100% or negative

MemAvailable fallback calculation adds cached memory twice. For older Linux: 'USED_MEMORY_KB=$((TOTAL_MEMORY_KB - FREE_MEMORY_KB))' excluding buffers/cache. Or upgrade kernel to 3.14+ with MemAvailable support. Verify memory calculation logic. Test with various Linux versions.

macOS vm_stat parsing fails showing zero memory usage

PAGE_SIZE extraction fails when format changes. Hardcode: 'PAGE_SIZE=4096' (Intel) or 'PAGE_SIZE=16384' (Apple Silicon M1/M2). Or use: 'sysctl hw.pagesize | awk '{print $2}''. Verify page size detection. Test with various macOS versions.

pgrep returns processes from other users causing inflated dev memory

pgrep matches all users. Restrict: 'pgrep -u $USER -f "$process"' showing only current user's processes. Or filter: 'ps -u $USER -o pid,comm,rss' for ownership validation. Verify user filtering. Test with various user configurations.

Docker stats command hangs indefinitely when containers unhealthy

docker stats --no-stream blocks on slow containers. Add timeout: 'timeout 5 docker stats --no-stream' or skip: 'docker stats --no-stream --format json 2>/dev/null | head -n 1' limiting output. Verify timeout handling. Test with various container states.

Hook execution time exceeds timeout (5000ms) on large systems

Process enumeration slow with 100+ dev processes. Increase timeout: '"timeout": 10000' in hookConfig. Or limit: 'pgrep -f "$process" | head -20' checking only top processes. Verify timeout configuration. Test with various system sizes.

Swap usage detection fails on systems without swap

Hook checks for swap existence before calculating percentages. Verify swap detection: 'if [ -f /proc/swaps ]' (Linux) or 'sysctl vm.swapusage' (macOS). Handle no-swap scenarios gracefully. Test with various swap configurations.

Process memory calculation incorrect for multi-threaded processes

VmRSS includes all threads. For accurate per-process memory, sum thread memory or use process group memory. Verify thread handling. Test with various process types. Consider using process group aggregation.

Memory monitoring shows incorrect values after system sleep/wake

System memory stats may be stale after sleep. Refresh memory information or add sleep detection. Verify memory refresh logic. Test with sleep/wake cycles. Consider adding memory refresh before monitoring.

• Source repositorygithub.com 2026-07-13T15:19:32-07:00
• Documentationcode.claude.com