Time to build a CRDT! Specifically a grow-only counter that works across distributed nodes without coordination. This is where distributed systems theory gets practical.
Implements a grow-only (increment-only) counter
Each node maintains its own counter value
Nodes periodically sync to get the global view
No coordination needed for increments
Used a G-Counter (Grow-only Counter) CRDT:
Each node tracks increments per node (vector of counters)
To increment: just bump your own counter
To read: sum all nodes' counters
To merge: take the max for each node position
Convergence: All nodes eventually see the same total
No Coordination: Increments are pure local operations
Partition Tolerant: Works even during network splits
Monotonic: Counter never decreases
Vector of counters (one per node)
Periodic state exchange between nodes
Max-based merging for conflict resolution
Clean separation of local vs global operations
Mathematical properties guarantee correctness
No need for locks, consensus, or coordination
Naturally partition tolerant
Simple to reason about
Pros:
Zero coordination overhead
Partition tolerant by design
Eventually consistent
Simple local operations
Cons:
Space grows with number of nodes
Only supports increment (no decrement)
Network overhead for state sync
This pattern shows up everywhere in distributed systems - any time you need shared state without coordination, CRDTs are often the answer.
