# Availability

> The proportion of time a system is operational and able to serve requests.

Record: `lexicon:availability`
Kind: quality-attribute
Layer: [Correctness Core](https://banes-lab.com/records/layer/correctness-core.md)
Canonical: https://banes-lab.com/ontology/lexicon#lexicon-availability

Listed in [Lexicon terms](https://banes-lab.com/api/records/lexicon.md), after [Registry Availability](https://banes-lab.com/records/lexicon/registry-availability.md) and before [Security](https://banes-lab.com/records/lexicon/security.md).

## Category

- [Quality Attributes](https://banes-lab.com/records/lexicon-category/quality-attributes.md)

## In tension with

- [Control Plane](https://banes-lab.com/records/architecture/control-plane.md)
- [Leader Election](https://banes-lab.com/records/architecture/leader-election.md)
- [Consensus](https://banes-lab.com/records/architecture/consensus.md)
- [Fail Safe](https://banes-lab.com/records/architecture/fail-safe.md)
- [Fail Secure](https://banes-lab.com/records/architecture/fail-secure.md)
- [Single Source of Truth](https://banes-lab.com/records/architecture/single-source-of-truth.md)
- [Consistency](https://banes-lab.com/records/architecture/consistency.md)
- [Control Plane / Availability](https://banes-lab.com/records/tension/availability-control-plane.md)
- [Leader Election / Availability](https://banes-lab.com/records/tension/availability-leader-election.md)
- [Consensus / Availability](https://banes-lab.com/records/tension/availability-consensus.md)
- [Fail Safe / Availability](https://banes-lab.com/records/tension/availability-fail-safe.md)
- [Fail Secure / Availability](https://banes-lab.com/records/tension/availability-fail-secure.md)
- [Single Source of Truth / Availability](https://banes-lab.com/records/tension/availability-single-source-of-truth.md)
- [Consistency / Availability](https://banes-lab.com/records/tension/availability-consistency.md)

## Reinforced by

- [Eventual Consistency](https://banes-lab.com/records/architecture/eventual-consistency.md)
- [Horizontal Scaling](https://banes-lab.com/records/architecture/horizontal-scaling.md)
- [Load Balancing](https://banes-lab.com/records/architecture/load-balancing.md)
- [Failover](https://banes-lab.com/records/architecture/failover.md)
- [Replication](https://banes-lab.com/records/architecture/replication.md)
- [Blue-Green Deployment](https://banes-lab.com/records/architecture/blue-green-deployment.md)

## Linked from

- [Separate, trade, or mitigate](https://banes-lab.com/software-architecture/principles/separate-trade-or-mitigate.md)
- [Architectural rules and principles](https://banes-lab.com/software-architecture/glossary/architectural-principles.md)
- [Control / Coordination / Centralization](https://banes-lab.com/ontology/principles/architecture-category-control-coordination-centralization.md)
- [Event / Messaging / Asynchronous Architecture](https://banes-lab.com/ontology/principles/architecture-category-event-messaging-asynchronous-architecture.md)
- [Error Handling / Resilience](https://banes-lab.com/ontology/principles/architecture-category-error-handling-resilience.md)
- [Scalability / Performance / Optimization](https://banes-lab.com/ontology/principles/architecture-category-scalability-performance-optimization.md)
- [Self-Healing / Recovery / Deployment Safety](https://banes-lab.com/ontology/principles/architecture-category-self-healing-recovery-deployment-safety.md)
- [Schema / Canonical Data / Semantics](https://banes-lab.com/ontology/principles/architecture-category-schema-canonical-data-semantics.md)
- [Transactions / State / Concurrency](https://banes-lab.com/ontology/principles/architecture-category-transactions-state-concurrency.md)
- [The resolutions](https://banes-lab.com/ontology/schema/the-resolutions.md)