rollout-weights.md

Linkerd Rollout Weights

This guide shows you how to use weights in Flagger to have more fine-grained rollouts.

By default Flagger allows to use linear promotion metrics, with the start value, the step and maximum weight value in 0 to 100 range.

Example:

canary:
  analysis:
    promotion:
      maxWeight: 50
      stepWeight: 20

This configuration performs analysis starting from 20, increasing by 20 until weight goes above 50.
We would have steps (canary weight : primary weight):

• 20 (20 : 80)
• 40 (40 : 60)
• 60 (60 : 40)
• promotion

In order to enable non-linear promotion a new parameters were introduced:

• fullWeight - determines the sum of canary and primary weights, i.e. the maximum possible weight which can be set to the split
• stepWeights - determines the ordered array of weights, which shall be used during canary promotion.

Example:

canary:
  analysis:
    promotion:
      fullWeight: 1000
      stepWeights: [1, 10, 100, 800]

This configuration performs analysis starting from 1, going through stepWeights values till 800.
We would have steps (canary weight : primary weight):

• 1 (1 : 999)
• 10 (10 : 990)
• 100 (100 : 900)
• 800 (800 : 200)
• promotion