{
  "schema_version": 2,
  "id": "operate/rs/databases/active-active/causal-consistency",
  "title": "Enable causal consistency",
  "url": "https://redis.io/docs/latest/operate/rs/databases/active-active/causal-consistency/",
  "summary": "Enable causal consistency in an Active-Active database.",
  "tags": [
    "docs",
    "operate",
    "rs"
  ],
  "last_updated": "2026-10-01T15:48:36+01:00",
  "page_type": "content",
  "content_hash": "0718a5e832f06fc84792f4d788192fdfd303967776710496e8730d4ab9f2c1e7",
  "sections": [
    {
      "id": "overview",
      "title": "Overview",
      "role": "overview",
      "text": "When you enable causal consistency in Active-Active databases,\nthe order of operations on a specific key are maintained across all Active-Active database instances.\n\nFor example, if operations A and B were applied on the same key and the effect of A was observed by the instance that initiated B before B was applied to the key.\nAll instances of an Active-Active database would then observe the effect of A before observing the effect of B.\nThis way, any causal relationship between operations on the same key is also observed and maintained by every replica."
    },
    {
      "id": "enable-causal-consistency",
      "title": "Enable causal consistency",
      "role": "content",
      "text": "When you create an Active-Active database, you can enable causal consistency in the Cluster Manager UI:\n\n1. In the **Participating clusters** section of the **Create Active-Active database** screen, locate **Causal Consistency**:\n\n    ![The Participating clusters section of the Create Active-Active database screen.](https://redis.io/docs/latest/images/rs/screenshots/databases/active-active-databases/create-a-a-db-participating-clusters.png)\n\n1. Click **Change** to open the **Causal Consistency** dialog.\n\n1. Select **Enabled**:\n\n    ![Enabled is selected in the Causal Consistency dialog.](https://redis.io/docs/latest/images/rs/screenshots/databases/active-active-databases/enable-causal-consistency.png)\n\n1. Click **Change** to confirm your selection.\n\nAfter database creation, you can only turn causal consistency on or off using the REST API or `crdb-cli`.\nThe updated setting only affects commands and operations received after the change."
    },
    {
      "id": "causal-consistency-side-effects",
      "title": "Causal consistency side effects",
      "role": "content",
      "text": "When the causal consistency option is enabled, each instance maintains the order of operations it received from another instance\nand relays that information to all other N-2 instances,\nwhere N represents the number of instances used by the Active-Active database.\n\nAs a result, network traffic is increased by a factor of (N-2).\nThe memory consumed by each instance and overall performance are also impacted when causal consistency is activated."
    }
  ],
  "examples": []
}