Now it gets interesting! Multiple nodes need to coordinate and share broadcast messages. This is where we enter the land of distributed algorithms.
What it Does
- Multiple nodes receive broadcast messages
- Nodes gossip messages to each other to ensure everyone has everything
- Still handle read requests returning all known messages
- Use topology information to optimize communication
The Approach
Built a gossip protocol:
- When a node receives a broadcast, it stores locally
- Then forwards to all neighbor nodes
- Neighbors store and forward to their neighbors
- Eventually all nodes have all messages
Used the topology from Maelstrom to determine who to gossip with.
Key Challenges
- Message Loops: Nodes can forward the same message back and forth
- Duplicate Handling: Same message might arrive via multiple paths
- Network Efficiency: Don't want to spam the network
Solutions
- Deduplication: Only store and forward messages we haven't seen
- Topology Awareness: Use provided network topology for efficient routing
- Async Gossiping: Don't block the main handler while gossiping
What I Learned
- Gossip protocols are simple but effective
- Deduplication is crucial in distributed systems
- Network topology matters for efficiency
- Always handle failures gracefully (some gossip messages might fail)
This sets us up for the fault tolerance challenge - what happens when network partitions occur?
