Feature Gates

Feature gates are configuration switches that enable or disable specific features in TiDB Operator. These features are generally experimental, and enabling them might require restarting certain components for the changes to take effect.

You can configure feature gates in the spec.featureGates field of the Cluster Custom Resource (CR). The following example shows how to enable the FeatureModification feature gate:

spec:
  featureGates:
    FeatureModification: true

Supported feature gates

This section describes the feature gates supported by TiDB Operator. For definitions of feature stages, see Feature gate stages.

FeatureModification

• When this feature is enabled, you can modify the spec.featureGates configuration.
• Default value: false
• Stage: Alpha in v2.0 and later versions
• Components requiring restart: None

VolumeAttributesClass

• When this feature is enabled, you can modify the VolumeAttributesClass attribute of a PVC. This feature depends on the corresponding Kubernetes capability. For more information, see the Kubernetes documentation for VolumeAttributesClass.
• Default value: false
• Stage: Alpha in v2.0 and later versions
• Components requiring restart: None

DisablePDDefaultReadinessProbe

• When this feature is enabled, TiDB Operator no longer checks PD readiness using TCP probes.
• Default value: false
• Stage: Alpha in v2.0 and later versions
• Components requiring restart: PD

UsePDReadyAPI

• When this feature is enabled, TiDB Operator checks PD readiness using the /ready API. For implementation details, see tikv/pd #8749.
• Default value: false
• Stage: Alpha in v2.0 and later versions
• Components requiring restart: PD

SessionTokenSigning

• When this feature is enabled, TiDB Operator automatically configures the session-token-signing-cert and session-token-signing-key parameters for TiDB.
• Default value: false
• Stage: Alpha in v2.0 and later versions
• Components requiring restart: TiDB

Feature gate stages

TiDB Operator classifies feature gates into three stages based on feature maturity: Alpha, Beta, and GA.

Alpha

Alpha-stage features have the following characteristics:

• Disabled by default.
• Recommended only for newly created clusters.
• Dynamic enabling or disabling in existing clusters is not guaranteed.
• Known or unknown issues might occur after being enabled.
• Not recommended for production environments unless risks are fully evaluated and validated.

Beta

Beta-stage features have the following characteristics:

• Typically have undergone thorough testing.
• Recommended to enable in all newly created clusters.
• Usually support enabling or disabling in existing clusters, but might require restarting related components.

GA

GA (General Availability) features have the following characteristics:

• Typically have undergone long-term and large-scale testing.
• Enabled by default.
• Cannot be disabled using feature gates.