Redis Quota

The redisquota adapter can be used to support Istio’s quota management system. It depends on a Redis server to store quota values.

Params

redisquota adapter supports the rate limit quota using either fixed or rolling window algorithm. And it is using Redis as a shared data storage.

Example configuration:

redisServerUrl: localhost:6379
connectionPoolSize: 10
quotas:
  - name: requestCount.quota.istio-system
    maxAmount: 50
    validDuration: 60s
    bucketDuration: 1s
    rateLimitAlgorithm: ROLLING_WINDOW
    overrides:
      - dimensions:
          destination: ratings
          source: reviews
        maxAmount: 12
      - dimensions:
          destination: reviews
        maxAmount: 5

Field	Type	Description
`quotas`	`Params.Quota[]`	The set of known quotas. At least one quota configuration is required
`redisServerUrl`	`string`	Redis connection string : ex) localhost:6379
`connectionPoolSize`	`int64`	Maximum number of idle connections to redis Default is 10 connections per every CPU as reported by runtime.NumCPU.

Params.Override

Field	Type	Description
`dimensions`	`map<string, string>`	The specific dimensions for which this override applies. String representation of instance dimensions is used to check against configured dimensions. dimensions should not be empty
`maxAmount`	`int64`	The upper limit for this quota override. This value should be bigger than 0

Params.Quota

Field	Type	Description
`name`	`string`	The name of the quota
`maxAmount`	`int64`	The upper limit for this quota. max_amount should be bigger than 0
`validDuration`	`google.protobuf.Duration`	The amount of time allocated quota remains valid before it is automatically released. This is only meaningful for rate limit quotas. value should be 0 < valid_duration
`bucketDuration`	`google.protobuf.Duration`	bucketduration will be ignored if ratelimitalgorithm is FIXEDWINDOW value should be 0 < bucketduration < validduration
`rateLimitAlgorithm`	`Params.QuotaAlgorithm`	Quota management algorithm. The default value is FIXED_WINDOW
`overrides`	`Params.Override[]`	Overrides associated with this quota. The first matching override is applied.

Params.QuotaAlgorithm

Algorithms for rate-limiting:

Name	Description
`FIXED_WINDOW`	FIXED_WINDOW The fixed window approach can allow 2x peak specified rate, whereas the rolling-window doesn’t.
`ROLLING_WINDOW`	ROLLING_WINDOW The rolling window algorithm’s additional precision comes at the cost of increased redis resource usage.