Redis

The Redis health checker is a custom health checker (with envoy.health_checkers.redis as name) which checks Redis upstream hosts. It sends a Redis PING command and expect a PONG response. The upstream Redis server can respond with anything other than PONG to cause an immediate active health check failure. Optionally, Envoy can perform EXISTS on a user-specified key. If the key does not exist it is considered a passing health check. This allows the user to mark a Redis instance for maintenance by setting the specified key to any value and waiting for traffic to drain.

An example setting for custom_health_check as a Redis health checker is shown below:

custom_health_check:
  name: envoy.health_checkers.redis
    typed_config:
      "@type": type.googleapis.com/envoy.extensions.health_checkers.redis.v3.Redis
      key: foo

• v3 API reference

Statistics

The Redis health checker emits some statistics in the health_check.redis. namespace.

Name	Description
exists_failure	Total number of health check failures caused by EXISTS check failure.