syntax = "proto3";

package envoy.config.cluster.redis;

import "google/protobuf/duration.proto";
import "google/protobuf/wrappers.proto";

import "udpa/annotations/status.proto";
import "validate/validate.proto";

option java_package = "io.envoyproxy.envoy.config.cluster.redis";
option java_outer_classname = "RedisClusterProto";
option java_multiple_files = true;
option go_package = "github.com/envoyproxy/go-control-plane/envoy/config/cluster/redis";
option (udpa.annotations.file_status).package_version_status = FROZEN;

// [#protodoc-title: Redis Cluster Configuration]
// This cluster adds support for `Redis Cluster <https://redis.io/topics/cluster-spec>`_, as part
// of :ref:`Envoy's support for Redis Cluster <arch_overview_redis>`.
//
// Redis Cluster is an extension of Redis which supports sharding and high availability (where a
// shard that loses its primary fails over to a replica, and designates it as the new primary).
// However, as there is no unified frontend or proxy service in front of Redis Cluster, the client
// (in this case Envoy) must locally maintain the state of the Redis Cluster, specifically the
// topology. A random node in the cluster is queried for the topology using the `CLUSTER SLOTS
// command <https://redis.io/commands/cluster-slots>`_. This result is then stored locally, and
// updated at user-configured intervals.
//
// Additionally, if
// :ref:`enable_redirection<envoy_api_field_config.filter.network.redis_proxy.v2.RedisProxy.ConnPoolSettings.enable_redirection>`
// is true, then moved and ask redirection errors from upstream servers will trigger a topology
// refresh when they exceed a user-configured error threshold.
//
// Example:
//
// .. code-block:: yaml
//
//     name: name
//     connect_timeout: 0.25s
//     dns_lookup_family: V4_ONLY
//     hosts:
//     - socket_address:
//       address: foo.bar.com
//       port_value: 22120
//     cluster_type:
//       name: envoy.clusters.redis
//       typed_config:
//         "@type": type.googleapis.com/google.protobuf.Struct
//         value:
//           cluster_refresh_rate: 30s
//           cluster_refresh_timeout: 0.5s
//           redirect_refresh_interval: 10s
//           redirect_refresh_threshold: 10
// [#extension: envoy.clusters.redis]

// [#next-free-field: 7]
message RedisClusterConfig {
  // Interval between successive topology refresh requests. If not set, this defaults to 5s.
  google.protobuf.Duration cluster_refresh_rate = 1 [(validate.rules).duration = {gt {}}];

  // Timeout for topology refresh request. If not set, this defaults to 3s.
  google.protobuf.Duration cluster_refresh_timeout = 2 [(validate.rules).duration = {gt {}}];

  // The minimum interval that must pass after triggering a topology refresh request before a new
  // request can possibly be triggered again. Any errors received during one of these
  // time intervals are ignored. If not set, this defaults to 5s.
  google.protobuf.Duration redirect_refresh_interval = 3;

  // The number of redirection errors that must be received before
  // triggering a topology refresh request. If not set, this defaults to 5.
  // If this is set to 0, topology refresh after redirect is disabled.
  google.protobuf.UInt32Value redirect_refresh_threshold = 4;

  // The number of failures that must be received before triggering a topology refresh request.
  // If not set, this defaults to 0, which disables the topology refresh due to failure.
  uint32 failure_refresh_threshold = 5;

  // The number of hosts became degraded or unhealthy before triggering a topology refresh request.
  // If not set, this defaults to 0, which disables the topology refresh due to degraded or
  // unhealthy host.
  uint32 host_degraded_refresh_threshold = 6;
}
