Merge pull request #1352 from ChenLingPeng/kube-scale

Allow more events to be buffered before the backend starts

Documentation/configuration.md

@@ -88,6 +88,8 @@ The command line options outlined above can also be specified via environment va
 For example `--etcd-endpoints=http://10.0.0.2:2379` is equivalent to `FLANNELD_ETCD_ENDPOINTS=http://10.0.0.2:2379` environment variable.
 Any command line option can be turned into an environment variable by prefixing it with `FLANNELD_`, stripping leading dashes, converting to uppercase and replacing all other dashes to underscores.
 
+`EVENT_QUEUE_DEPTH` is another environment variable to indicate the kubernetes scale. Set `EVENT_QUEUE_DEPTH` to adapter your cluster node numbers. If not set, default value is 5000. 
+
 ## Health Check
 
 Flannel provides a health check http endpoint `healthz`. Currently this endpoint will blindly

Documentation/kube-flannel.yml

@@ -220,6 +220,8 @@ spec:
           valueFrom:
             fieldRef:
               fieldPath: metadata.namespace
+        - name: EVENT_QUEUE_DEPTH
+          value: "5000"
         volumeMounts:
         - name: run
           mountPath: /run/flannel

subnet/kube/kube.go

@@ -21,6 +21,7 @@ import (
 	"io/ioutil"
 	"net"
 	"os"
+	"strconv"
 	"time"
 
 	"github.com/flannel-io/flannel/pkg/ip"
@@ -141,7 +142,18 @@ func newKubeSubnetManager(ctx context.Context, c clientset.Interface, sc *subnet
 	ksm.client = c
 	ksm.nodeName = nodeName
 	ksm.subnetConf = sc
-	ksm.events = make(chan subnet.Event, 5000)
+	scale := 5000
+	scaleStr := os.Getenv("EVENT_QUEUE_DEPTH")
+	if scaleStr != "" {
+		n, err := strconv.Atoi(scaleStr)
+		if err != nil {
+			return nil, fmt.Errorf("env EVENT_QUEUE_DEPTH=%s format error: %v", scaleStr, err)
+		}
+		if n > 0 {
+			scale = n
+		}
+	}
+	ksm.events = make(chan subnet.Event, scale)
 	indexer, controller := cache.NewIndexerInformer(
 		&cache.ListWatch{
 			ListFunc: func(options metav1.ListOptions) (runtime.Object, error) {