Performance Comparison: v5.1.x vs v6.x

Benchmarked on MongoDB 8.2, 3-node replica set, January 2026

---

Executive Summary

Aspect	v5.1.x → v6.x	Improvement
Connection Pool	Global lock → Per-host locking	+38% throughput
Messaging	Improved threading & lock handling	Better under load
$in Queries	Same (MongoDB indexed)	~8% faster
SSL/TLS	Not available → Full support	✅ New feature

---

Real Benchmark Results

v5.1.9 vs v6.x (MongoDB Cluster)

Benchmark	v5.1.9	v6.x	Improvement
Connection Pool (20 threads × 100 ops)	22,869 ops/sec	31,642 ops/sec	+38%
Messaging (500 msgs, default settings)	10 msgs/sec*	21 msgs/sec	+110%
$in Query (500 values, indexed)	3.40 ms	3.14 ms	+8%
Bulk Writes (10K docs)	43,544 docs/sec	38,219 docs/sec	-12%**

*v5 messaging hit timeout (345/500 received) — may indicate stability issues under load. **Bulk write difference under investigation.

Messaging Performance by Backend

Backend	Throughput	Latency	vs MongoDB
MongoDB (3-node replica set)	89 msgs/sec	11.28 ms	1x
MorphiumServer	223 msgs/sec	4.47 ms	2.5x faster
InMemory Driver (direct)	281 msgs/sec	3.56 ms	3.2x faster

Key insight: MorphiumServer is 2.5x faster than real MongoDB for messaging tests!

$in Query: Indexed vs Non-Indexed

Field	MongoDB	InMemory
Indexed (counter, 500 values)	5.52 ms	81.30 ms
Non-indexed (category, 50 values)	10.39 ms	16.60 ms

MongoDB indexes make a huge difference. InMemory shows O(n×m) behavior without indexes.

---

Architecture Improvements

PooledDriver: Per-Host Locking

v5.1.x:

// Global synchronized blocks - all hosts blocked
private synchronized MongoConnection borrowConnection(String host) {
    synchronized (connectionPool) { ... }
}

v6.x:

// Per-host isolation with modern concurrency
private final Map<String, Host> hosts = new ConcurrentHashMap<>();

class Host {
    private final BlockingQueue<ConnectionContainer> pool;
    private final AtomicInteger borrowedConnections;
}

Result: Operations on different hosts don't block each other.

Messaging Improvements

Both v5 and v6 use ChangeStream, but v6 has:

• Better thread pool management — Configurable core/max sizes
• Improved resume token handling — More reliable after disconnects
• Lock optimizations — Less contention in message processing
• Java 21 threading — Ready for virtual threads

Result: Better throughput with optimized settings.

---

MorphiumServer for Testing

MorphiumServer provides a MongoDB-compatible server backed by InMemoryDriver:

Feature	Benefit
No MongoDB required	CI/CD without Docker
2.5x faster messaging	Faster test suites
Full wire protocol	Drop-in replacement
Clustering support	Test replica set scenarios

Quick Start

# Start server
mvn exec:java -Dexec.mainClass="de.caluga.morphium.server.MorphiumServerCLI" \
    -Dexec.args="-p 17017"

# Connect Morphium
MorphiumConfig cfg = new MorphiumConfig();
cfg.addHostToSeed("localhost:17017");
cfg.setDatabase("test");
Morphium m = new Morphium(cfg);

---

InMemory vs MongoDB: When to Use What

Use Case	Recommendation
Unit tests	InMemory Driver (fastest)
Integration tests	MorphiumServer (realistic + fast)
Load testing	Real MongoDB (production-like)
CI/CD pipelines	MorphiumServer (no dependencies)

InMemory Driver Limitations

• No real indexes (full collection scan)
• $in queries are O(n×m) not O(n+m)
• No persistence across restarts

---

Tuning Messaging Performance

Default settings are conservative. For high-throughput:

// Optimized settings
SingleCollectionMessaging messaging = new SingleCollectionMessaging(
    morphium,
    10,      // pause: 10ms (default: 100ms)
    true,    // multithreaded
    100      // windowSize (default: 10)
);

Setting	Default	Optimized	Effect
pause	100ms	10ms	Lower latency
multithreaded	false	true	Parallel processing
windowSize	10	100	Batch efficiency

---

Migration Checklist

Upgrading from v5.1.x to v6.x:

• [ ] Java 21 required
• [ ] Update Messaging → SingleCollectionMessaging
• [ ] Review messaging settings for optimal performance
• [ ] Enable SSL/TLS for production (new in v6!)
• [ ] Consider MorphiumServer for tests

See Migration Guide v5→v6 for details.

---

Benchmarks run on Mac Studio M2 Ultra, MongoDB 8.2.4, Morphium 6.1.8-SNAPSHOT