From 68dca7a5a80b743ab3e74a8550ed67d1620b6120 Mon Sep 17 00:00:00 2001
From: TzZtzt <trafalgarz@outlook.com>
Date: Thu, 24 Mar 2022 10:27:18 +0800
Subject: [PATCH] Optimize CSI Plugin node server logic (#1582)

* Cache node to avoid frequent requests to api server

Signed-off-by: TrafalgarZZZ <trafalgarz@outlook.com>

* Add env variable switch for allowing node server to patch cached node

Signed-off-by: TrafalgarZZZ <trafalgarz@outlook.com>
---
 .../fluid/fluid/templates/csi/daemonset.yaml  |  2 ++
 pkg/csi/plugins/nodeserver.go                 | 30 +++++++++++++++++--
 pkg/ddc/goosefs/transform_permission.go       |  2 +-
 3 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/charts/fluid/fluid/templates/csi/daemonset.yaml b/charts/fluid/fluid/templates/csi/daemonset.yaml
index ae594553611..a8d455f1324 100644
--- a/charts/fluid/fluid/templates/csi/daemonset.yaml
+++ b/charts/fluid/fluid/templates/csi/daemonset.yaml
@@ -84,6 +84,8 @@ spec:
             - name: MOUNT_ROOT
               value: {{ .Values.runtime.mountRoot | quote }}
             {{- end }}
+            - name: ALLOW_PATCH_STALE_NODE
+              value: "true"
             - name: KUBELET_ROOTDIR
               value: {{ .Values.csi.kubelet.rootDir }}
             - name: CSI_ENDPOINT
diff --git a/pkg/csi/plugins/nodeserver.go b/pkg/csi/plugins/nodeserver.go
index 534311a4034..a8d2eab4422 100644
--- a/pkg/csi/plugins/nodeserver.go
+++ b/pkg/csi/plugins/nodeserver.go
@@ -24,6 +24,7 @@ import (
 	"github.com/fluid-cloudnative/fluid/pkg/utils/dataset/volume"
 	"github.com/fluid-cloudnative/fluid/pkg/utils/kubeclient"
 	"github.com/pkg/errors"
+	v1 "k8s.io/api/core/v1"
 	"os"
 	"os/exec"
 	"sigs.k8s.io/controller-runtime/pkg/client"
@@ -40,12 +41,17 @@ import (
 	"k8s.io/utils/mount"
 )
 
+const (
+	AllowPatchStaleNodeEnv = "ALLOW_PATCH_STALE_NODE"
+)
+
 type nodeServer struct {
 	nodeId string
 	*csicommon.DefaultNodeServer
 	client    client.Client
 	apiReader client.Reader
 	mutex     sync.Mutex
+	node      *v1.Node
 }
 
 func (ns *nodeServer) NodePublishVolume(ctx context.Context, req *csi.NodePublishVolumeRequest) (*csi.NodePublishVolumeResponse, error) {
@@ -234,7 +240,7 @@ func (ns *nodeServer) NodeUnstageVolume(ctx context.Context, req *csi.NodeUnstag
 	var labelsToModify common.LabelsToModify
 	labelsToModify.Delete(fuseLabelKey)
 
-	node, err := kubeclient.GetNode(ns.apiReader, ns.nodeId)
+	node, err := ns.getNode()
 	if err != nil {
 		glog.Errorf("NodeUnstageVolume: can't get node %s: %v", ns.nodeId, err)
 		return nil, errors.Wrapf(err, "NodeUnstageVolume: can't get node %s", ns.nodeId)
@@ -266,7 +272,7 @@ func (ns *nodeServer) NodeStageVolume(ctx context.Context, req *csi.NodeStageVol
 	var labelsToModify common.LabelsToModify
 	labelsToModify.Add(fuseLabelKey, "true")
 
-	node, err := kubeclient.GetNode(ns.apiReader, ns.nodeId)
+	node, err := ns.getNode()
 	if err != nil {
 		glog.Errorf("NodeStageVolume: can't get node %s: %v", ns.nodeId, err)
 		return nil, errors.Wrapf(err, "NodeStageVolume: can't get node %s", ns.nodeId)
@@ -313,14 +319,34 @@ func (ns *nodeServer) getRuntimeNamespacedName(volumeContext map[string]string,
 		runtimeName, nameFound := volumeContext[common.VolumeAttrName]
 		runtimeNamespace, nsFound := volumeContext[common.VolumeAttrNamespace]
 		if nameFound && nsFound {
+			glog.V(3).Infof("Get runtime namespace(%s) and name(%s) from volume context", runtimeNamespace, runtimeName)
 			return runtimeNamespace, runtimeName, nil
 		}
 	}
 
 	// Fallback: query API Server to get namespaced name
+	glog.Infof("Get runtime namespace and name directly from api server with volumeId %s", volumeId)
 	return volume.GetNamespacedNameByVolumeId(ns.apiReader, volumeId)
 }
 
+// getNode first checks cached node
+func (ns *nodeServer) getNode() (node *v1.Node, err error) {
+	// Default to allow patch stale node info
+	if envVar, found := os.LookupEnv(AllowPatchStaleNodeEnv); !found || "true" == envVar {
+		if ns.node != nil {
+			glog.V(3).Infof("Found cached node %s", ns.node.Name)
+			return ns.node, nil
+		}
+	}
+
+	if node, err = kubeclient.GetNode(ns.apiReader, ns.nodeId); err != nil {
+		return nil, err
+	}
+	glog.V(1).Infof("Got node %s from api server", node.Name)
+	ns.node = node
+	return ns.node, nil
+}
+
 func checkMountInUse(volumeName string) (bool, error) {
 	var inUse bool
 	glog.Infof("Try to check if the volume %s is being used", volumeName)
diff --git a/pkg/ddc/goosefs/transform_permission.go b/pkg/ddc/goosefs/transform_permission.go
index 088353fc819..93f9bad13cf 100644
--- a/pkg/ddc/goosefs/transform_permission.go
+++ b/pkg/ddc/goosefs/transform_permission.go
@@ -1,5 +1,5 @@
 /*
-Copyright 2022 The Fluid Authors. 
+Copyright 2022 The Fluid Authors.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.