# Parallelism

> A technique for running independent units of work at the same time on several cores or workers.

Record: `architecture:parallelism`
Kind: technique
Layer: [Performance Core](https://banes-lab.com/records/layer/performance-core.md)
Severity: contextual
Scope: algorithm, processing, runtime
Canonical: https://banes-lab.com/ontology#architecture-parallelism

Listed in [Architecture principles](https://banes-lab.com/api/records/architecture.md), after [Concurrency](https://banes-lab.com/records/architecture/concurrency.md) and before [Throughput](https://banes-lab.com/records/architecture/throughput.md).

## Repair

- Refactored by: Split Work, Add Parallel Execution
- Detected by: CPU bottlenecks with independent work
- Violated by: serial processing of independent heavy tasks
- Measured by: speedup, utilization
- Enforced by: performance benchmarks

## Requires

- [Independent Work Units](https://banes-lab.com/records/lexicon/independent-work-units.md)

## Reinforces

- [Throughput](https://banes-lab.com/records/architecture/throughput.md)
- [Performance](https://banes-lab.com/records/lexicon/performance.md)

## Enables

- [Multi-Core Utilization](https://banes-lab.com/records/lexicon/multi-core-utilization.md)

## Conflicts with

- [Sequential Bottleneck](https://banes-lab.com/records/lexicon/sequential-bottleneck.md)

## In tension with

- [Coordination Overhead](https://banes-lab.com/records/lexicon/coordination-overhead.md)
- [Causality](https://banes-lab.com/records/architecture/causality.md)
- [Causality / Parallelism](https://banes-lab.com/records/tension/causality-parallelism.md)

## Tensions

- [Parallelism / Coordination Overhead](https://banes-lab.com/records/tension/coordination-overhead-parallelism.md)

## Severity

- [contextual](https://banes-lab.com/records/vocabulary/severity-contextual.md)

## Category

- [Scalability / Performance / Optimization](https://banes-lab.com/records/architecture-category/scalability-performance-optimization.md)

## Enabled by

- [Partitioning](https://banes-lab.com/records/architecture/partitioning.md)

## Reinforced by

- [Fan-out/Fan-in](https://banes-lab.com/records/architecture/fan-out-fan-in.md)

## Linked from

- [Causality / Ordering / Distributed Time](https://banes-lab.com/ontology/principles/architecture-category-causality-ordering-distributed-time.md)
- [Scalability / Performance / Optimization](https://banes-lab.com/ontology/principles/architecture-category-scalability-performance-optimization.md)
- [Streaming / Pipeline / Dataflow Processing](https://banes-lab.com/ontology/principles/architecture-category-streaming-pipeline-dataflow-processing.md)
- [Core Vocabulary](https://banes-lab.com/ontology/lexicon/lexicon-category-core-vocabulary.md)
- [Quality Attributes](https://banes-lab.com/ontology/lexicon/lexicon-category-quality-attributes.md)
- [Scalability / Performance / Optimization](https://banes-lab.com/ontology/lexicon/lexicon-category-scalability-performance-optimization.md)
- [Severity levels](https://banes-lab.com/ontology/schema/the-vocabulary-severity.md)
- [The resolutions](https://banes-lab.com/ontology/schema/the-resolutions.md)