fix: rename READY deadline to CLUSTER deadline ENV (#10535)

cmd/config/api/api.go

@@ -31,17 +31,23 @@ import (
 const (
 	apiRequestsMax             = "requests_max"
 	apiRequestsDeadline        = "requests_deadline"
-	apiReadyDeadline           = "ready_deadline"
+	apiClusterDeadline         = "cluster_deadline"
 	apiCorsAllowOrigin         = "cors_allow_origin"
 	apiRemoteTransportDeadline = "remote_transport_deadline"
 
 	EnvAPIRequestsMax             = "MINIO_API_REQUESTS_MAX"
 	EnvAPIRequestsDeadline        = "MINIO_API_REQUESTS_DEADLINE"
-	EnvAPIReadyDeadline           = "MINIO_API_READY_DEADLINE"
+	EnvAPIClusterDeadline         = "MINIO_API_CLUSTER_DEADLINE"
 	EnvAPICorsAllowOrigin         = "MINIO_API_CORS_ALLOW_ORIGIN"
 	EnvAPIRemoteTransportDeadline = "MINIO_API_REMOTE_TRANSPORT_DEADLINE"
 )
 
+// Deprecated key and ENVs
+const (
+	apiReadyDeadline    = "ready_deadline"
+	EnvAPIReadyDeadline = "MINIO_API_READY_DEADLINE"
+)
+
 // DefaultKVS - default storage class config
 var (
 	DefaultKVS = config.KVS{
@@ -54,7 +60,7 @@ var (
 			Value: "10s",
 		},
 		config.KV{
-			Key:   apiReadyDeadline,
+			Key:   apiClusterDeadline,
 			Value: "10s",
 		},
 		config.KV{
@@ -72,7 +78,7 @@ var (
 type Config struct {
 	RequestsMax             int           `json:"requests_max"`
 	RequestsDeadline        time.Duration `json:"requests_deadline"`
-	ReadyDeadline           time.Duration `json:"ready_deadline"`
+	ClusterDeadline         time.Duration `json:"cluster_deadline"`
 	CorsAllowOrigin         []string      `json:"cors_allow_origin"`
 	RemoteTransportDeadline time.Duration `json:"remote_transport_deadline"`
 }
@@ -90,6 +96,9 @@ func (sCfg *Config) UnmarshalJSON(data []byte) error {
 
 // LookupConfig - lookup api config and override with valid environment settings if any.
 func LookupConfig(kvs config.KVS) (cfg Config, err error) {
+	// remove this since we have removed this already.
+	kvs.Delete(apiReadyDeadline)
+
 	if err = config.CheckValidKeys(config.APISubSys, kvs, DefaultKVS); err != nil {
 		return cfg, err
 	}
@@ -109,7 +118,7 @@ func LookupConfig(kvs config.KVS) (cfg Config, err error) {
 		return cfg, err
 	}
 
-	readyDeadline, err := time.ParseDuration(env.Get(EnvAPIReadyDeadline, kvs.Get(apiReadyDeadline)))
+	clusterDeadline, err := time.ParseDuration(env.Get(EnvAPIClusterDeadline, kvs.Get(apiClusterDeadline)))
 	if err != nil {
 		return cfg, err
 	}
@@ -124,7 +133,7 @@ func LookupConfig(kvs config.KVS) (cfg Config, err error) {
 	return Config{
 		RequestsMax:             requestsMax,
 		RequestsDeadline:        requestsDeadline,
-		ReadyDeadline:           readyDeadline,
+		ClusterDeadline:         clusterDeadline,
 		CorsAllowOrigin:         corsAllowOrigin,
 		RemoteTransportDeadline: remoteTransportDeadline,
 	}, nil

cmd/config/config.go

@@ -267,6 +267,16 @@ func (kvs KVS) Get(key string) string {
 	return ""
 }
 
+// Delete - deletes the key if present from the KV list.
+func (kvs *KVS) Delete(key string) {
+	for i, kv := range *kvs {
+		if kv.Key == key {
+			*kvs = append((*kvs)[:i], (*kvs)[i+1:]...)
+			return
+		}
+	}
+}
+
 // Lookup - lookup a key in a list of KVS
 func (kvs KVS) Lookup(key string) (string, bool) {
 	for _, kv := range kvs {

cmd/handler-api.go

@@ -31,7 +31,7 @@ type apiConfig struct {
 
 	requestsDeadline time.Duration
 	requestsPool     chan struct{}
-	readyDeadline    time.Duration
+	clusterDeadline  time.Duration
 	corsAllowOrigins []string
 }
 
@@ -39,7 +39,7 @@ func (t *apiConfig) init(cfg api.Config, setDriveCount int) {
 	t.mu.Lock()
 	defer t.mu.Unlock()
 
-	t.readyDeadline = cfg.ReadyDeadline
+	t.clusterDeadline = cfg.ClusterDeadline
 	t.corsAllowOrigins = cfg.CorsAllowOrigin
 
 	var apiRequestsMaxPerNode int
@@ -74,15 +74,15 @@ func (t *apiConfig) getCorsAllowOrigins() []string {
 	return corsAllowOrigins
 }
 
-func (t *apiConfig) getReadyDeadline() time.Duration {
+func (t *apiConfig) getClusterDeadline() time.Duration {
 	t.mu.RLock()
 	defer t.mu.RUnlock()
 
-	if t.readyDeadline == 0 {
+	if t.clusterDeadline == 0 {
 		return 10 * time.Second
 	}
 
-	return t.readyDeadline
+	return t.clusterDeadline
 }
 
 func (t *apiConfig) getRequestsPool() (chan struct{}, <-chan time.Time) {

cmd/healthcheck-handler.go

@@ -33,7 +33,7 @@ func ClusterCheckHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	ctx, cancel := context.WithTimeout(ctx, globalAPIConfig.getReadyDeadline())
+	ctx, cancel := context.WithTimeout(ctx, globalAPIConfig.getClusterDeadline())
 	defer cancel()
 
 	opts := HealthOptions{Maintenance: r.URL.Query().Get("maintenance") == "true"}

docs/metrics/README.md

@@ -4,10 +4,10 @@ MinIO server exposes monitoring data over endpoints. Monitoring tools can pick t
 
 ### Healthcheck Probe
 
-MinIO server has two healthcheck related un-authenticated endpoints, a liveness probe to indicate if server is working fine and a readiness probe to indicate if server is not accepting connections due to heavy load.
+MinIO server has two healthcheck related un-authenticated endpoints, a liveness probe to indicate if server is responding, cluster probe to check if server can be taken down for maintenance.
 
 - Liveness probe available at `/minio/health/live`
-- Readiness probe available at `/minio/health/ready`
+- Cluster probe available at `/minio/health/cluster`
 
 Read more on how to use these endpoints in [MinIO healthcheck guide](https://github.com/minio/minio/blob/master/docs/metrics/healthcheck/README.md).
 

docs/metrics/healthcheck/README.md

@@ -1,6 +1,6 @@
 ## MinIO Healthcheck
 
-MinIO server exposes three un-authenticated, healthcheck endpoints liveness probe, readiness probe and a cluster probe at `/minio/health/live`, `/minio/health/ready` and `/minio/health/cluster` respectively.
+MinIO server exposes three un-authenticated, healthcheck endpoints liveness probe and a cluster probe at `/minio/health/live`, `/minio/health/ready` and `/minio/health/cluster` respectively.
 
 ### Liveness probe
 
@@ -12,31 +12,13 @@ This probe always responds with '200 OK'. When liveness probe fails, Kubernetes
               path: /minio/health/live
               port: 9000
               scheme: HTTP
-            initialDelaySeconds: 3
+            initialDelaySeconds: 120
-            periodSeconds: 1
+            periodSeconds: 15
-            timeoutSeconds: 1
+            timeoutSeconds: 10
             successThreshold: 1
             failureThreshold: 3
 ```
 
-### Readiness probe
-
-This probe always responds with '200 OK'. When readiness probe fails, Kubernetes like platforms *do not* forward traffic to a pod.
-
-```
-          readinessProbe:
-            httpGet:
-              path: /minio/health/ready
-              port: 9000
-              scheme: HTTP
-            initialDelaySeconds: 3
-            periodSeconds: 1
-            timeoutSeconds: 1
-            successThreshold: 1
-            failureThreshold: 3
-
-```
-
 ### Cluster probe
 This probe is not useful in almost all cases, this is meant for administrators to see if quorum is available in any given cluster. The reply is '200 OK' if cluster has quorum if not it returns '503 Service Unavailable'.
 
@@ -49,6 +31,7 @@ Content-Security-Policy: block-all-mixed-content
 Server: MinIO/GOGET.GOGET
 Vary: Origin
 X-Amz-Bucket-Region: us-east-1
+X-Minio-Write-Quorum: 3
 X-Amz-Request-Id: 16239D6AB80EBECF
 X-Xss-Protection: 1; mode=block
 Date: Tue, 21 Jul 2020 00:36:14 GMT
@@ -68,5 +51,6 @@ Vary: Origin
 X-Amz-Bucket-Region: us-east-1
 X-Amz-Request-Id: 16239D63820C6E76
 X-Xss-Protection: 1; mode=block
+X-Minio-Write-Quorum: 3
 Date: Tue, 21 Jul 2020 00:35:43 GMT
 ```

docs/orchestration/kubernetes/README.md

@@ -12,9 +12,7 @@ There are multiple options to deploy MinIO on Kubernetes:
 
 ## Monitoring MinIO in Kubernetes
 
-MinIO server exposes un-authenticated readiness and liveness endpoints so Kubernetes can natively identify unhealthy MinIO containers. MinIO also exposes Prometheus compatible data on a different endpoint to enable Prometheus users to natively monitor their MinIO deployments.
+MinIO server exposes un-authenticated liveness endpoints so Kubernetes can natively identify unhealthy MinIO containers. MinIO also exposes Prometheus compatible data on a different endpoint to enable Prometheus users to natively monitor their MinIO deployments.
-
-_Note_ : Readiness check is not allowed in distributed MinIO deployment. This is because Kubernetes doesn't allow any traffic to containers whose Readiness checks fail, and in a distributed setup, MinIO server can't respond to Readiness checks until all the nodes are reachable. So, Liveness checks are recommended native Kubernetes monitoring approach for distributed MinIO StatefulSets. Read more about Kubernetes recommendations for [container probes](https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle/#container-probes).
 
 ## Explore Further