Patterns

35 items

System Design Pattern

Coordination2pctwo-phase-commitdistributed-transactionscoordinatoratomicityadvanced

Two-Phase Commit Pattern

Distributed transaction coordination

Used in: Database Transactions, Saga Pattern, XA Transactions|25 min read

Key Takeaways

All-or-Nothing Atomicity

Either all participants commit the transaction or none do. Guarantees no partial failures. Essential when data must be consistent across systems.

Blocking Protocol

If coordinator fails after sending prepare but before commit/abort, participants are stuck holding locks. Cannot proceed or rollback safely. This is 2PC's biggest weakness.

Latency Penalty

Minimum 4 network hops: prepare request, prepare response, commit request, commit response. Plus time for logging. Significantly slower than local transactions.

Key Takeaways

All-or-Nothing Atomicity

Either all participants commit the transaction or none do. Guarantees no partial failures. Essential when data must be consistent across systems.

Blocking Protocol

If coordinator fails after sending prepare but before commit/abort, participants are stuck holding locks. Cannot proceed or rollback safely. This is 2PC's biggest weakness.

Latency Penalty

Minimum 4 network hops: prepare request, prepare response, commit request, commit response. Plus time for logging. Significantly slower than local transactions.

Coordinator is Single Point

Coordinator failure blocks entire transaction. Need coordinator HA (often itself using consensus). Adds complexity and failure modes.

Aspect	Advantage	Disadvantage

Patterns

Horizontal Scaling Pattern

Retry with Backoff Pattern

Replication Pattern

Caching Strategies Pattern

Persistent Connections Pattern

Load Balancing Pattern

Fan-out Pattern

Fan-in Pattern

Circuit Breaker Pattern

Eventual Consistency Pattern

Queue-based Load Leveling Pattern

Bloom Filters Pattern

Time-Series Storage Pattern

Bulkhead Pattern

Batch Processing Pattern

Write-Ahead Log Pattern

API Gateway Pattern

Backend for Frontend Pattern

Sidecar Pattern

Idempotency Pattern

Rate Limiting Pattern

Backpressure Pattern

Pub/Sub Pattern

Strong Consistency Pattern

Conflict Resolution Pattern

Leader Election Pattern

Consensus Protocols Pattern

CQRS Pattern

LSM Trees Pattern

Sharding Pattern

Event Sourcing Pattern

Stream Processing Pattern

Change Data Capture Pattern

Distributed Locking Pattern