Swarm/MEMORY_OPTIMIZATION_SUMMARY.md

Memory Optimization Summary for DysonNetwork.Drive

Current State

• Idle Memory Usage: ~600MB
• Target: Reduce to ~200-300MB (50-67% reduction)

Changes Implemented

1. DbContext Pooling ✓

Files Changed:

• DysonNetwork.Drive/Startup/ServiceCollectionExtensions.cs
• DysonNetwork.Drive/AppDatabase.cs

What Changed:

• Changed from AddDbContext<AppDatabase>() to AddDbContextPool<AppDatabase>(AppDatabase.ConfigureOptions)
• Added ConfigureOptions static method to configure DbContext for pooling

Expected Memory Savings: 30-50MB How: Reuses DbContext instances instead of creating new ones for each request

2. Database Connection Pool Reduction ✓

Files Changed:

• settings/drive.json

What Changed:

• Connection pool size: 20 → 5
• Idle lifetime: 60s → 30s

Expected Memory Savings: 20-40MB How: Fewer active database connections maintained in memory

3. HttpClient Connection Limits ✓

Files Changed:

• DysonNetwork.Shared/Extensions.cs

What Changed:

• Added MaxConnectionsPerServer = 5 to HttpClientHandler
• Reduces maximum connections per server from default (100+) to 5

Expected Memory Savings: 30-50MB How: Limits connection pool size, releases idle connections faster

4. gRPC Client Connection Limits ✓

Files Changed:

• DysonNetwork.Shared/Registry/GrpcChannelManager.cs (new)
• DysonNetwork.Shared/Registry/ServiceInjectionHelper.cs (updated)

What Changed:

• Created ConfigureGrpcDefaults() extension method
• Applied to all 10 gRPC clients
• Set MaxConnectionsPerServer = 2 per client
• Total connections: 10 clients × 2 = 20 (down from 1000+)

Expected Memory Savings: 100-200MB How: Each gRPC client maintains its own HTTP/2 connection pool

5. Redis Configuration Optimization ✓

Files Changed:

• DysonNetwork.Shared/Extensions.cs

What Changed:

• Added connection timeouts: 5s connect, 3s sync/async
• Added retry limit: 3 attempts
• Prevents hung connections from accumulating

Expected Memory Savings: 20-30MB How: Prevents stale connections and reduces buffer sizes

6. NATS Configuration ✓

Files Changed:

• DysonNetwork.Shared/Extensions.cs

What Changed:

• Kept default NATS configuration
• Removed custom config that was causing compilation errors
• Defaults are memory-efficient

Expected Memory Savings: N/A (already optimized)

Total Expected Memory Savings

Optimization	Expected Savings	Status
DbContext Pooling	30-50 MB	✓ Implemented
DB Pool Reduction	20-40 MB	✓ Implemented
HttpClient Limits	30-50 MB	✓ Implemented
gRPC Client Limits	100-200 MB	✓ Implemented
Redis Config	20-30 MB	✓ Implemented
TOTAL	200-370 MB
Projected Idle Memory	230-400 MB	(from 600MB)

Next Steps (Not Yet Implemented)

Phase 2: Lazy gRPC Clients (Additional 50-100MB savings)

• Create factory pattern for gRPC clients
• Only initialize clients on first use
• Requires code changes in all service classes

Phase 3: Query Optimizations (Additional 20-40MB savings)

• Add .AsNoTracking() to read-only queries
• Replace .Count(t => ...) with .CountAsync(...)
• Optimize database queries to load less data

Phase 4: Cache TTL Reduction (Additional 10-20MB savings)

• Reduce cache duration from 15-30 min to 5-10 min
• Implement partial caching instead of full objects

Monitoring Recommendations

1. Monitor Memory After Deployment

   docker stats <container-name>
   

   Expected: 230-400MB (down from 600MB)

2. Monitor Connection Counts

   # PostgreSQL connections
   psql -U postgres -c "SELECT count(*) FROM pg_stat_activity;"
   
   # Redis connections
   redis-cli CLIENT LIST | wc -l
   

3. Monitor gRPC Connections

   • Check logs for "Creating gRPC channel" messages
   • Should see 1 message per unique endpoint (not per client)

Rolling Back

If issues occur, rollback changes:

git checkout HEAD~1 -- DysonNetwork.Drive/Startup/ServiceCollectionExtensions.cs
git checkout HEAD~1 -- DysonNetwork.Drive/AppDatabase.cs
git checkout HEAD~1 -- settings/drive.json
git checkout HEAD~1 -- DysonNetwork.Shared/Extensions.cs
git checkout HEAD~1 -- DysonNetwork.Shared/Registry/

Testing

To verify memory improvements:

# Before (current)
docker-compose up -d drive
docker stats drive

# After (with changes)
docker-compose restart drive
# Wait 5 minutes for steady state
docker stats drive

Look for:

• Reduced memory usage in Docker stats
• Fewer database connections
• No increase in errors/latency
• Stable connection counts

Notes

• All changes are backward compatible
• No API changes
• Should not affect functionality
• Only reduces resource usage
• All projects compile successfully