Concurrency Control

Kind: mechanism

Layer: Atomic Boundary

Record: architecture:concurrency-control

Severity: mandatory

Scope: transaction, memory, distributed system

Canonical: Ontology

A mechanism that coordinates concurrent access to shared state, through locks, versions or compare-and-swap.

Listed in Architecture principles, after Isolation and before Optimistic Locking.

Requires

• Shared State Identification

Reinforces

• Isolation
• Correctness

Enables

• Safe Parallel Mutation

Conflicts with

• Race Conditions
• Lost Update

In tension with

• Performance

Tensions

• Concurrency Control / Performance

Violated by

• Race Conditions

Refactored by

• Pessimistic Locking
• Make Immutable
• Optimistic Locking

Severity

• mandatory

Category

• Transactions / State / Concurrency

Required by

• Concurrency

Linked from

• Coordination is software
• Anti-patterns
• Correctness / Determinism / Verification
• Scalability / Performance / Optimization
• Transactions / State / Concurrency
• Core Vocabulary
• Quality Attributes
• Transactions / State / Concurrency
• Severity levels
• The resolutions