FailoverPolicy

Proto: failover_policy.proto

Package: resilience.policy.gloo.solo.io

Use a failover policy to determine where to reroute traffic in case of failure. If a backing service in a virtual destination is unhealthy, Gloo Mesh re-routes traffic to another healthy backing service by locality, as specified in the FailoverPolicy config. FailoverPolicies are applied at the Destination level.

About failover policies link

Note that you can use failover policies in combination with other policies, such as outlier detection or retry policies.

• FailoverPolicy: Choose where to direct traffic to, based on locality.
• OutlierDetectionPolicy: Determine when and for how long to remove unhealthy destinations from the pool of healthy destinations.
• RetryTimeoutPolicy: Decide how many times to retry requests before the outlier detection policy considers the request as failing and removes the service from the pool of healthy destinations.

To fine-tune traffic flow according to your operational needs, Istio has several locality settings that you can configure via the FailoverPolicy, as shown in the following example configurations.

Distribute with weight example link

Distribute traffic based on locality to enhance user experience in terms of performance, or to manage the load across resources more efficiently. Note that this setting does not fail over traffic, but instead distributes traffic.

  apiVersion: resilience.policy.gloo.solo.io/v2
kind: FailoverPolicy
metadata:
  annotations:
    cluster.solo.io/cluster: ""
  name: locality-based-failover
  namespace: bookinfo
spec:
  applyToDestinations:
  - kind: VIRTUAL_DESTINATION
    selector: {}
  config:
    localityMappings:
    - from:
        region: us-east
      to:
      - region: us-west
        weight: 50
      - region: us-east
        weight: 50
  

Failover example link

This example selects all virtual destinations in the workspace, and fails over traffic from any destinations served in the us-east region to any matching destinations only in the us-west region.

  apiVersion: resilience.policy.gloo.solo.io/v2
kind: FailoverPolicy
metadata:
  annotations:
    cluster.solo.io/cluster: ""
  name: locality-based-failover
  namespace: bookinfo
spec:
  applyToDestinations:
  - kind: VIRTUAL_DESTINATION
    selector: {}
  config:
    localityMappings:
    - from:
        region: us-east
      to:
      - region: us-west
  

Failover priority example link

The following example prioritizes destinations for failover traffic based on key-value labels. Destinations that match the most labels are prioritized first. For more information, including about important limitations especially in multicluster scenarios, see the failover guide.

  apiVersion: resilience.policy.gloo.solo.io/v2
kind: FailoverPolicy
metadata:
  annotations:
    cluster.solo.io/cluster: ""
  name: locality-based-failover-with-priority
  namespace: bookinfo
spec:
  applyToDestinations:
  - kind: VIRTUAL_DESTINATION
    selector: {}
  config:
    priorityLabels:
      labels:
      - version=v1
      - version=v4
      - topology.istio.io/subzone=a
  

FailoverPolicyReport link

The report shows the resources that the policy selects after the policy is successfully applied.

FailoverPolicyReport.WorkspacesEntry link

FailoverPolicySpec link

Specifications for the policy.

FailoverPolicySpec.Config link

FailoverPolicySpec.Config.LocalityMappings link

FailoverPolicySpec.Config.LocalityMappings.DestinationLocality link

A geographic location defined by a region, zone, and sub-zone along with the weight for the destination.

FailoverPolicySpec.Config.LocalityMappings.OriginatingLocality link

A geographic location defined by a region, zone, and sub-zone.

FailoverPolicyStatus link

The status of the policy after it is applied to your Gloo environment.