{
  "code": null,
  "collection": "architecture",
  "href": "https://banes-lab.com/ontology#architecture-read-replica",
  "id": "read-replica",
  "kind": "technique",
  "layer": {
    "href": "https://banes-lab.com/ontology/schema#layer-performance-core",
    "json": "https://banes-lab.com/json/records/layer/performance-core",
    "label": "Performance Core",
    "markdown": "https://banes-lab.com/records/layer/performance-core.md",
    "ref": "layer:performance-core"
  },
  "name": "Read Replica",
  "ref": "architecture:read-replica",
  "relations": [
    {
      "links": [
        {
          "href": "https://banes-lab.com/ontology#architecture-replication",
          "json": "https://banes-lab.com/json/records/architecture/replication",
          "label": "Replication",
          "markdown": "https://banes-lab.com/records/architecture/replication.md",
          "ref": "architecture:replication"
        }
      ],
      "relation": "requires"
    },
    {
      "links": [
        {
          "href": "https://banes-lab.com/ontology#architecture-horizontal-scaling",
          "json": "https://banes-lab.com/json/records/architecture/horizontal-scaling",
          "label": "Horizontal Scaling",
          "markdown": "https://banes-lab.com/records/architecture/horizontal-scaling.md",
          "ref": "architecture:horizontal-scaling"
        },
        {
          "href": "https://banes-lab.com/ontology#architecture-load-balancing",
          "json": "https://banes-lab.com/json/records/architecture/load-balancing",
          "label": "Load Balancing",
          "markdown": "https://banes-lab.com/records/architecture/load-balancing.md",
          "ref": "architecture:load-balancing"
        }
      ],
      "relation": "reinforces"
    },
    {
      "links": [
        {
          "href": "https://banes-lab.com/ontology/lexicon#lexicon-read-traffic-offload",
          "json": "https://banes-lab.com/json/records/lexicon/read-traffic-offload",
          "label": "Read Traffic Offload",
          "markdown": "https://banes-lab.com/records/lexicon/read-traffic-offload.md",
          "ref": "lexicon:read-traffic-offload"
        }
      ],
      "relation": "enables"
    },
    {
      "links": [
        {
          "href": "https://banes-lab.com/ontology/lexicon#lexicon-single-primary-read-contention",
          "json": "https://banes-lab.com/json/records/lexicon/single-primary-read-contention",
          "label": "Single-Primary Read Contention",
          "markdown": "https://banes-lab.com/records/lexicon/single-primary-read-contention.md",
          "ref": "lexicon:single-primary-read-contention"
        }
      ],
      "relation": "conflicts-with"
    },
    {
      "links": [
        {
          "href": "https://banes-lab.com/ontology/lexicon#lexicon-read-your-writes-consistency",
          "json": "https://banes-lab.com/json/records/lexicon/read-your-writes-consistency",
          "label": "Read-Your-Writes Consistency",
          "markdown": "https://banes-lab.com/records/lexicon/read-your-writes-consistency.md",
          "ref": "lexicon:read-your-writes-consistency"
        }
      ],
      "relation": "tensions-with"
    },
    {
      "links": [
        {
          "href": "https://banes-lab.com/ontology/schema#tension-read-replica-read-your-writes-consistency",
          "json": "https://banes-lab.com/json/records/tension/read-replica-read-your-writes-consistency",
          "label": "Read Replica / Read-Your-Writes Consistency",
          "markdown": "https://banes-lab.com/records/tension/read-replica-read-your-writes-consistency.md",
          "ref": "tension:read-replica-read-your-writes-consistency"
        }
      ],
      "relation": "tensions"
    },
    {
      "links": [
        {
          "href": "https://banes-lab.com/ontology/lexicon#lexicon-single-primary-read-contention",
          "json": "https://banes-lab.com/json/records/lexicon/single-primary-read-contention",
          "label": "Single-Primary Read Contention",
          "markdown": "https://banes-lab.com/records/lexicon/single-primary-read-contention.md",
          "ref": "lexicon:single-primary-read-contention"
        }
      ],
      "relation": "violated-by"
    },
    {
      "links": [
        {
          "href": "https://banes-lab.com/ontology/schema#vocabulary-severity-contextual",
          "json": "https://banes-lab.com/json/records/vocabulary/severity-contextual",
          "label": "contextual",
          "markdown": "https://banes-lab.com/records/vocabulary/severity-contextual.md",
          "ref": "vocabulary:severity-contextual"
        }
      ],
      "relation": "severity"
    },
    {
      "links": [
        {
          "href": "https://banes-lab.com/ontology#architecture-category-scalability-performance-optimization",
          "json": "https://banes-lab.com/json/records/architecture-category/scalability-performance-optimization",
          "label": "Scalability / Performance / Optimization",
          "markdown": "https://banes-lab.com/records/architecture-category/scalability-performance-optimization.md",
          "ref": "architecture-category:scalability-performance-optimization"
        }
      ],
      "relation": "category"
    },
    {
      "links": [
        {
          "href": "https://banes-lab.com/ontology#architecture-failover",
          "json": "https://banes-lab.com/json/records/architecture/failover",
          "label": "Failover",
          "markdown": "https://banes-lab.com/records/architecture/failover.md",
          "ref": "architecture:failover"
        },
        {
          "href": "https://banes-lab.com/ontology#architecture-redundancy",
          "json": "https://banes-lab.com/json/records/architecture/redundancy",
          "label": "Redundancy",
          "markdown": "https://banes-lab.com/records/architecture/redundancy.md",
          "ref": "architecture:redundancy"
        }
      ],
      "relation": "refactors"
    },
    {
      "links": [
        {
          "href": "https://banes-lab.com/ontology#architecture-category-scalability-performance-optimization",
          "json": "https://banes-lab.com/json/ontology/principles/architecture-category-scalability-performance-optimization",
          "label": "Scalability / Performance / Optimization",
          "markdown": "https://banes-lab.com/ontology/principles/architecture-category-scalability-performance-optimization.md",
          "ref": "chapter:/ontology#architecture-category-scalability-performance-optimization"
        },
        {
          "href": "https://banes-lab.com/ontology#architecture-category-self-healing-recovery-deployment-safety",
          "json": "https://banes-lab.com/json/ontology/principles/architecture-category-self-healing-recovery-deployment-safety",
          "label": "Self-Healing / Recovery / Deployment Safety",
          "markdown": "https://banes-lab.com/ontology/principles/architecture-category-self-healing-recovery-deployment-safety.md",
          "ref": "chapter:/ontology#architecture-category-self-healing-recovery-deployment-safety"
        },
        {
          "href": "https://banes-lab.com/ontology/lexicon#lexicon-category-scalability-performance-optimization",
          "json": "https://banes-lab.com/json/ontology/lexicon/lexicon-category-scalability-performance-optimization",
          "label": "Scalability / Performance / Optimization",
          "markdown": "https://banes-lab.com/ontology/lexicon/lexicon-category-scalability-performance-optimization.md",
          "ref": "chapter:/ontology/lexicon#lexicon-category-scalability-performance-optimization"
        },
        {
          "href": "https://banes-lab.com/ontology/schema#the-vocabulary-severity",
          "json": "https://banes-lab.com/json/ontology/schema/the-vocabulary-severity",
          "label": "Severity levels",
          "markdown": "https://banes-lab.com/ontology/schema/the-vocabulary-severity.md",
          "ref": "chapter:/ontology/schema#the-vocabulary-severity"
        },
        {
          "href": "https://banes-lab.com/ontology/schema#the-resolutions",
          "json": "https://banes-lab.com/json/ontology/schema/the-resolutions",
          "label": "The resolutions",
          "markdown": "https://banes-lab.com/ontology/schema/the-resolutions.md",
          "ref": "chapter:/ontology/schema#the-resolutions"
        }
      ],
      "relation": "linked-from"
    }
  ],
  "summary": "A technique for routing read queries to replicated copies of a database, so the primary handles only writes.",
  "siblings": {
    "next": {
      "href": "https://banes-lab.com/ontology#architecture-queuing-theory",
      "json": "https://banes-lab.com/json/records/architecture/queuing-theory",
      "label": "Queuing Theory",
      "markdown": "https://banes-lab.com/records/architecture/queuing-theory.md",
      "ref": "architecture:queuing-theory"
    },
    "previous": {
      "href": "https://banes-lab.com/ontology#architecture-cdn-edge-caching",
      "json": "https://banes-lab.com/json/records/architecture/cdn-edge-caching",
      "label": "CDN / Edge Caching",
      "markdown": "https://banes-lab.com/records/architecture/cdn-edge-caching.md",
      "ref": "architecture:cdn-edge-caching"
    }
  },
  "up": {
    "href": null,
    "json": "https://banes-lab.com/json/api/records/architecture",
    "label": "Architecture principles",
    "markdown": "https://banes-lab.com/api/records/architecture.md",
    "ref": "api:records/architecture"
  },
  "aliases": [],
  "exemplar": {
    "after": "const foo = await replicaRouter.read(fooQuery);\nawait primaryDb.write(fooCommand);",
    "before": "const foo = await primaryDb.query(fooQuery);\nawait primaryDb.write(fooCommand);",
    "lang": "ts",
    "medium": "code"
  },
  "formedBy": null,
  "scope": [
    "service",
    "database",
    "scalability"
  ],
  "severity": "contextual"
}