Performance Monitoring

Comprehensive guide to monitoring and optimizing performance of the ActivityPub MCP Server. Learn about key metrics, profiling techniques, and optimization strategies.

📊 Key Performance Metrics

Response Time

Tool Execution Time: Time to complete MCP tool calls
HTTP Request Time: ActivityPub/WebFinger request latency
Cache Hit/Miss Time: Cache lookup performance
End-to-End Latency: Total user request to response time

Resource Usage

Memory Usage: Heap size and garbage collection
CPU Usage: Processing load and utilization
Network I/O: Bandwidth and connection usage
Cache Size: Memory used by caching layers

Throughput

Requests per Second: Tool call frequency
Concurrent Connections: Simultaneous operations
Cache Hit Rate: Percentage of cache hits
Error Rate: Failed requests percentage

🔍 Monitoring Setup

Built-in Monitoring

The server includes built-in performance monitoring accessible via the health-check tool:

# Check server performance
health-check

# Access performance data via resource
activitypub://server-info

Available Metrics:

Request count and timing statistics
Memory usage and garbage collection stats
Cache performance metrics
Error counts and types

External Monitoring Tools

Node.js Profiling

# CPU profiling
node --prof server.js

# Memory profiling
node --inspect server.js

# Heap snapshots
node --inspect --inspect-brk server.js

Process Monitoring

# System resource usage
top -p $(pgrep -f activitypub-mcp)

# Detailed process info
ps aux | grep activitypub-mcp

# Memory details
cat /proc/$(pgrep -f activitypub-mcp)/status

📈 Performance Analysis

Response Time Analysis

1. Baseline Measurement

# Measure tool execution time
time discover-actor @mastodon@mastodon.social

# Benchmark multiple operations
for i in {1..10}; do
  time get-instance-info mastodon.social
done

2. Bottleneck Identification

Network Latency: Test with different instances
Cache Performance: Compare cached vs uncached requests
Processing Time: Profile JSON parsing and data transformation
Concurrency Issues: Test with multiple simultaneous requests

Memory Analysis

Memory Profiling

# Generate heap snapshot
kill -USR2 $(pgrep -f activitypub-mcp)

# Analyze with Chrome DevTools
node --inspect server.js
# Open chrome://inspect in Chrome

Memory Leak Detection

Monitor Growth: Track memory usage over time
Cache Limits: Verify cache size limits are enforced
Event Listeners: Check for unremoved listeners
Circular References: Look for objects preventing GC

Cache Performance

Cache Metrics

# Check cache statistics
curl activitypub://server-info | jq '.statistics'

# Monitor cache hit rate
watch -n 5 'curl -s activitypub://server-info | jq ".statistics.cacheHits, .statistics.cacheMisses"'

Optimization Strategies

TTL Tuning: Adjust cache expiration times
Size Limits: Optimize cache size vs hit rate
Eviction Policy: Use LRU for better performance
Preloading: Cache frequently accessed data

⚡ Optimization Strategies

Network Optimization

Connection Pooling: Reuse HTTP connections
Request Batching: Combine multiple requests
Compression: Enable gzip/brotli compression
Timeout Tuning: Optimize request timeouts
Retry Logic: Implement exponential backoff

Caching Optimization

Multi-level Caching: Memory + disk caching
Smart Invalidation: Selective cache clearing
Predictive Caching: Pre-fetch likely requests
Cache Warming: Populate cache on startup
Compression: Compress cached data

Processing Optimization

Async Operations: Non-blocking I/O
Stream Processing: Process data in chunks
Worker Threads: Offload CPU-intensive tasks
JSON Streaming: Parse large responses incrementally
Memory Pooling: Reuse objects and buffers

🚨 Performance Alerts

Threshold Configuration

Metric	Warning	Critical	Action
Response Time	> 5s	> 15s	Check network/cache
Memory Usage	> 80%	> 95%	Clear cache/restart
Error Rate	> 5%	> 15%	Check logs/connectivity
Cache Hit Rate	< 60%	< 40%	Tune cache settings

Monitoring Scripts

# Simple performance monitor
#!/bin/bash
while true; do
  MEMORY=$(ps -o pid,vsz,rss,comm -p $(pgrep -f activitypub-mcp))
  RESPONSE_TIME=$(curl -w "%{time_total}" -s -o /dev/null activitypub://server-info)

  echo "$(date): Memory: $MEMORY, Response: ${RESPONSE_TIME}s"

  if (( $(echo "$RESPONSE_TIME > 10" | bc -l) )); then
    echo "WARNING: High response time detected"
  fi

  sleep 60
done

📋 Performance Checklist

Daily Monitoring

□ Check server response times
□ Monitor memory usage trends
□ Review error logs
□ Verify cache hit rates
□ Check for memory leaks

Weekly Analysis

□ Analyze performance trends
□ Review slow queries
□ Check cache effectiveness
□ Monitor resource usage patterns
□ Update performance baselines

Monthly Optimization

□ Profile application performance
□ Optimize cache configurations
□ Review and tune timeouts
□ Analyze dependency performance
□ Plan capacity upgrades