Add exponential backoff to openstack loadbalancer functions

Using  exponential backoff to lower openstack load and reduce API call throttling

Change-Id: Iba806a12184d5e499a9ab8dc9f8dcc2e8303ef5b

openstack/BUILD

@@ -58,6 +58,7 @@ go_library(
         "//vendor/k8s.io/apimachinery/pkg/api/resource:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/types:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/net:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/util/wait:go_default_library",
         "//vendor/k8s.io/client-go/util/cert:go_default_library",
     ],
 )
@@ -80,6 +81,7 @@ go_test(
         "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/types:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/rand:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/util/wait:go_default_library",
     ],
 )
 

openstack/openstack_loadbalancer.go

@@ -39,6 +39,7 @@ import (
 	neutronports "github.com/gophercloud/gophercloud/openstack/networking/v2/ports"
 	"github.com/gophercloud/gophercloud/pagination"
 
+	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/kubernetes/pkg/api/v1"
 	"k8s.io/kubernetes/pkg/api/v1/service"
 	"k8s.io/kubernetes/pkg/cloudprovider"
@@ -46,8 +47,26 @@ import (
 
 // Note: when creating a new Loadbalancer (VM), it can take some time before it is ready for use,
 // this timeout is used for waiting until the Loadbalancer provisioning status goes to ACTIVE state.
-const loadbalancerActiveTimeoutSeconds = 120
-const loadbalancerDeleteTimeoutSeconds = 30
+const (
+	// loadbalancerActive* is configuration of exponential backoff for
+	// going into ACTIVE loadbalancer provisioning status. Starting with 1
+	// seconds, multiplying by 1.2 with each step and taking 19 steps at maximum
+	// it will time out after 128s, which roughly corresponds to 120s
+	loadbalancerActiveInitDealy = 1 * time.Second
+	loadbalancerActiveFactor    = 1.2
+	loadbalancerActiveSteps     = 19
+
+	// loadbalancerDelete* is configuration of exponential backoff for
+	// waiting for delete operation to complete. Starting with 1
+	// seconds, multiplying by 1.2 with each step and taking 13 steps at maximum
+	// it will time out after 32s, which roughly corresponds to 30s
+	loadbalancerDeleteInitDealy = 1 * time.Second
+	loadbalancerDeleteFactor    = 1.2
+	loadbalancerDeleteSteps     = 13
+
+	activeStatus = "ACTIVE"
+	errorStatus  = "ERROR"
+)
 
 // LoadBalancer implementation for LBaaS v1
 type LbaasV1 struct {
@@ -337,44 +356,6 @@ func getMembersByPoolID(client *gophercloud.ServiceClient, id string) ([]v2pools
 	return members, nil
 }
 
-// Each pool has exactly one or zero monitors. ListOpts does not seem to filter anything.
-func getMonitorByPoolID(client *gophercloud.ServiceClient, id string) (*v2monitors.Monitor, error) {
-	var monitorList []v2monitors.Monitor
-	err := v2monitors.List(client, v2monitors.ListOpts{PoolID: id}).EachPage(func(page pagination.Page) (bool, error) {
-		monitorsList, err := v2monitors.ExtractMonitors(page)
-		if err != nil {
-			return false, err
-		}
-
-		for _, monitor := range monitorsList {
-			// bugfix, filter by poolid
-			for _, pool := range monitor.Pools {
-				if pool.ID == id {
-					monitorList = append(monitorList, monitor)
-				}
-			}
-		}
-		if len(monitorList) > 1 {
-			return false, ErrMultipleResults
-		}
-		return true, nil
-	})
-	if err != nil {
-		if isNotFound(err) {
-			return nil, ErrNotFound
-		}
-		return nil, err
-	}
-
-	if len(monitorList) == 0 {
-		return nil, ErrNotFound
-	} else if len(monitorList) > 1 {
-		return nil, ErrMultipleResults
-	}
-
-	return &monitorList[0], nil
-}
-
 // Check if a member exists for node
 func memberExists(members []v2pools.Member, addr string, port int) bool {
 	for _, member := range members {
@@ -436,45 +417,59 @@ func getSecurityGroupRules(client *gophercloud.ServiceClient, opts rules.ListOpt
 }
 
 func waitLoadbalancerActiveProvisioningStatus(client *gophercloud.ServiceClient, loadbalancerID string) (string, error) {
-	start := time.Now().Second()
-	for {
+	backoff := wait.Backoff{
+		Duration: loadbalancerActiveInitDealy,
+		Factor:   loadbalancerActiveFactor,
+		Steps:    loadbalancerActiveSteps,
+	}
+
+	var provisioningStatus string
+	err := wait.ExponentialBackoff(backoff, func() (bool, error) {
 		loadbalancer, err := loadbalancers.Get(client, loadbalancerID).Extract()
 		if err != nil {
-			return "", err
+			return false, err
 		}
-		if loadbalancer.ProvisioningStatus == "ACTIVE" {
-			return "ACTIVE", nil
-		} else if loadbalancer.ProvisioningStatus == "ERROR" {
-			return "ERROR", fmt.Errorf("Loadbalancer has gone into ERROR state")
+		provisioningStatus = loadbalancer.ProvisioningStatus
+		if loadbalancer.ProvisioningStatus == activeStatus {
+			return true, nil
+		} else if loadbalancer.ProvisioningStatus == errorStatus {
+			return true, fmt.Errorf("Loadbalancer has gone into ERROR state")
+		} else {
+			return false, nil
 		}
 
-		time.Sleep(1 * time.Second)
+	})
 
-		if time.Now().Second()-start >= loadbalancerActiveTimeoutSeconds {
-			return loadbalancer.ProvisioningStatus, fmt.Errorf("Loadbalancer failed to go into ACTIVE provisioning status within alloted time")
-		}
+	if err == wait.ErrWaitTimeout {
+		err = fmt.Errorf("Loadbalancer failed to go into ACTIVE provisioning status within alloted time")
 	}
+	return provisioningStatus, err
 }
 
 func waitLoadbalancerDeleted(client *gophercloud.ServiceClient, loadbalancerID string) error {
-	start := time.Now().Second()
-	for {
+	backoff := wait.Backoff{
+		Duration: loadbalancerDeleteInitDealy,
+		Factor:   loadbalancerDeleteFactor,
+		Steps:    loadbalancerDeleteSteps,
+	}
+	err := wait.ExponentialBackoff(backoff, func() (bool, error) {
 		_, err := loadbalancers.Get(client, loadbalancerID).Extract()
 		if err != nil {
 			if err == ErrNotFound {
-				return nil
+				return true, nil
 			} else {
-				return err
+				return false, err
 			}
+		} else {
+			return false, nil
 		}
+	})
 
-		time.Sleep(1 * time.Second)
-
-		if time.Now().Second()-start >= loadbalancerDeleteTimeoutSeconds {
-			return fmt.Errorf("Loadbalancer failed to delete within the alloted time")
-		}
-
+	if err == wait.ErrWaitTimeout {
+		err = fmt.Errorf("Loadbalancer failed to delete within the alloted time")
 	}
+
+	return err
 }
 
 func toRuleProtocol(protocol v1.Protocol) rules.RuleProtocol {

openstack/openstack_test.go

@@ -30,39 +30,55 @@ import (
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/rand"
+	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/kubernetes/pkg/api/v1"
 )
 
-const volumeAvailableStatus = "available"
-const volumeInUseStatus = "in-use"
-const volumeCreateTimeoutSeconds = 30
-const testClusterName = "testCluster"
+const (
+	volumeAvailableStatus = "available"
+	volumeInUseStatus     = "in-use"
+	testClusterName       = "testCluster"
 
-func WaitForVolumeStatus(t *testing.T, os *OpenStack, volumeName string, status string, timeoutSeconds int) {
-	timeout := timeoutSeconds
-	start := time.Now().Second()
-	for {
-		time.Sleep(1 * time.Second)
-
-		if timeout >= 0 && time.Now().Second()-start >= timeout {
-			t.Logf("Volume (%s) status did not change to %s after %v seconds\n",
-				volumeName,
-				status,
-				timeout)
-			return
-		}
+	volumeStatusTimeoutSeconds = 30
+	// volumeStatus* is configuration of exponential backoff for
+	// waiting for specified volume status. Starting with 1
+	// seconds, multiplying by 1.2 with each step and taking 13 steps at maximum
+	// it will time out after 32s, which roughly corresponds to 30s
+	volumeStatusInitDealy = 1 * time.Second
+	volumeStatusFactor    = 1.2
+	volumeStatusSteps     = 13
+)
 
+func WaitForVolumeStatus(t *testing.T, os *OpenStack, volumeName string, status string) {
+	backoff := wait.Backoff{
+		Duration: volumeStatusInitDealy,
+		Factor:   volumeStatusFactor,
+		Steps:    volumeStatusSteps,
+	}
+	err := wait.ExponentialBackoff(backoff, func() (bool, error) {
 		getVol, err := os.getVolume(volumeName)
 		if err != nil {
-			t.Fatalf("Cannot get existing Cinder volume (%s): %v", volumeName, err)
+			return false, err
 		}
 		if getVol.Status == status {
 			t.Logf("Volume (%s) status changed to %s after %v seconds\n",
 				volumeName,
 				status,
-				timeout)
-			return
+				volumeStatusTimeoutSeconds)
+			return true, nil
+		} else {
+			return false, nil
 		}
+	})
+	if err == wait.ErrWaitTimeout {
+		t.Logf("Volume (%s) status did not change to %s after %v seconds\n",
+			volumeName,
+			status,
+			volumeStatusTimeoutSeconds)
+		return
+	}
+	if err != nil {
+		t.Fatalf("Cannot get existing Cinder volume (%s): %v", volumeName, err)
 	}
 }
 
@@ -360,7 +376,7 @@ func TestVolumes(t *testing.T) {
 	}
 	t.Logf("Volume (%s) created\n", vol)
 
-	WaitForVolumeStatus(t, os, vol, volumeAvailableStatus, volumeCreateTimeoutSeconds)
+	WaitForVolumeStatus(t, os, vol, volumeAvailableStatus)
 
 	diskId, err := os.AttachDisk(os.localInstanceID, vol)
 	if err != nil {
@@ -368,7 +384,7 @@ func TestVolumes(t *testing.T) {
 	}
 	t.Logf("Volume (%s) attached, disk ID: %s\n", vol, diskId)
 
-	WaitForVolumeStatus(t, os, vol, volumeInUseStatus, volumeCreateTimeoutSeconds)
+	WaitForVolumeStatus(t, os, vol, volumeInUseStatus)
 
 	devicePath := os.GetDevicePath(diskId)
 	if !strings.HasPrefix(devicePath, "/dev/disk/by-id/") {
@@ -382,7 +398,7 @@ func TestVolumes(t *testing.T) {
 	}
 	t.Logf("Volume (%s) detached\n", vol)
 
-	WaitForVolumeStatus(t, os, vol, volumeAvailableStatus, volumeCreateTimeoutSeconds)
+	WaitForVolumeStatus(t, os, vol, volumeAvailableStatus)
 
 	err = os.DeleteVolume(vol)
 	if err != nil {