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Do service creation/update/deletion work in a pool of goroutines, protecting

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each service with a lock to ensure that no two goroutines will process a
service at the same time. This is needed to avoid weird race conditions.
This commit is contained in:
Alex Robinson 2015-04-09 20:48:27 +00:00
parent 9a351e3670
commit fc08a0a71b
4 changed files with 107 additions and 72 deletions
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2
cmd/kube-controller-manager/app/controllermanager.go
View File

@ -50,7 +50,6 @@ type CMServer struct {
ClientConfig client.Config
CloudProvider string
CloudConfigFile string
ClusterName string
MinionRegexp string
NodeSyncPeriod time.Duration
ResourceQuotaSyncPeriod time.Duration
@ -102,7 +101,6 @@ func (s *CMServer) AddFlags(fs *pflag.FlagSet) {
client.BindClientConfigFlags(fs, &s.ClientConfig)
fs.StringVar(&s.CloudProvider, "cloud_provider", s.CloudProvider, "The provider for cloud services. Empty string for no provider.")
fs.StringVar(&s.CloudConfigFile, "cloud_config", s.CloudConfigFile, "The path to the cloud provider configuration file. Empty string for no configuration file.")
fs.StringVar(&s.ClusterName, "cluster_name", s.ClusterName, "The instance prefix for the cluster")
fs.StringVar(&s.MinionRegexp, "minion_regexp", s.MinionRegexp, "If non empty, and --cloud_provider is specified, a regular expression for matching minion VMs.")
fs.DurationVar(&s.NodeSyncPeriod, "node_sync_period", s.NodeSyncPeriod, ""+
"The period for syncing nodes from cloudprovider. Longer periods will result in "+

2
pkg/cloudprovider/cloud.go
View File

@ -42,6 +42,8 @@ type Clusters interface {
Master(clusterName string) (string, error)
}
// TODO(#6812): Use a shorter name that's less likely to be longer than cloud
// providers' name length limits.
func GetLoadBalancerName(clusterName, serviceNamespace, serviceName string) string {
return clusterName + "-" + serviceNamespace + "-" + serviceName
}

172
pkg/cloudprovider/servicecontroller/servicecontroller.go
View File

@ -19,19 +19,25 @@ package servicecontroller
import (
"fmt"
"net"
"sort"
"sync"
"time"
"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
"github.com/GoogleCloudPlatform/kubernetes/pkg/api/errors"
"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
"github.com/GoogleCloudPlatform/kubernetes/pkg/client/cache"
"github.com/GoogleCloudPlatform/kubernetes/pkg/cloudprovider"
"github.com/GoogleCloudPlatform/kubernetes/pkg/fields"
"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
"github.com/GoogleCloudPlatform/kubernetes/pkg/types"
"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
"github.com/golang/glog"
)
const (
workerGoroutines = 10
clientRetryCount = 5
clientRetryInterval = 5 * time.Second
@ -39,14 +45,24 @@ const (
notRetryable = false
)
type cachedService struct {
service *api.Service
// Ensures only one goroutine can operate on this service at any given time.
mu sync.Mutex
}
type serviceCache struct {
mu sync.Mutex // protects serviceMap
serviceMap map[string]*cachedService
}
type ServiceController struct {
cloud cloudprovider.Interface
kubeClient client.Interface
clusterName string
balancer cloudprovider.TCPLoadBalancer
zone cloudprovider.Zone
mu sync.Mutex // protects serviceMap
serviceMap map[string]*api.Service // keys generated by cache.MetaNamespaceKeyFunc
cache *serviceCache
}
// New returns a new service controller to keep cloud provider service resources
@ -56,7 +72,7 @@ func New(cloud cloudprovider.Interface, kubeClient client.Interface, clusterName
cloud: cloud,
kubeClient: kubeClient,
clusterName: clusterName,
serviceMap: make(map[string]*api.Service),
cache: &serviceCache{serviceMap: make(map[string]*cachedService)},
}
}
@ -75,7 +91,16 @@ func (s *ServiceController) Run() error {
return fmt.Errorf("ServiceController only works with real Client objects, but was passed something else satisfying the client Interface.")
}
go s.watchServices()
// Get the currently existing set of services and then all future creates
// and updates of services.
// No delta compressor is needed for the DeltaFIFO queue because we only ever
// care about the most recent state.
serviceQueue := cache.NewDeltaFIFO(cache.MetaNamespaceKeyFunc, nil, s.cache)
lw := cache.NewListWatchFromClient(s.kubeClient.(*client.Client), "services", api.NamespaceAll, fields.Everything())
cache.NewReflector(lw, &api.Service{}, serviceQueue, 0).Run()
for i := 0; i < workerGoroutines; i++ {
go s.watchServices(serviceQueue)
}
return nil
}
@ -102,15 +127,8 @@ func (s *ServiceController) init() error {
return nil
}
func (s *ServiceController) watchServices() {
// Get the currently existing set of services and then all future creates
// and updates of services.
// TODO: Add a compressor that intelligently squashes together updates?
keyLister := cache.KeyListerFunc(func() []string { return s.listKeys() })
serviceQueue := cache.NewDeltaFIFO(cache.MetaNamespaceKeyFunc, nil, keyLister)
lw := cache.NewListWatchFromClient(s.kubeClient.(*client.Client), "services", api.NamespaceAll, fields.Everything())
cache.NewReflector(lw, &api.Service{}, serviceQueue, 0).Run()
// TODO: Add proper retries rather than just re-adding to the queue?
// Loop infinitely, processing all service updates provided by the queue.
func (s *ServiceController) watchServices(serviceQueue *cache.DeltaFIFO) {
for {
newItem := serviceQueue.Pop()
deltas, ok := newItem.(cache.Deltas)
@ -129,7 +147,7 @@ func (s *ServiceController) watchServices() {
time.Sleep(5 * time.Second)
serviceQueue.AddIfNotPresent(deltas)
} else if err != nil {
glog.Errorf("Failed to process service delta. Not retrying: %v", err)
util.HandleError(fmt.Errorf("Failed to process service delta. Not retrying: %v", err))
}
}
}
@ -138,6 +156,8 @@ func (s *ServiceController) watchServices() {
// indicator of whether the processing should be retried.
func (s *ServiceController) processDelta(delta *cache.Delta) (error, bool) {
service, ok := delta.Object.(*api.Service)
var namespacedName types.NamespacedName
var cachedService *cachedService
if !ok {
// If the DeltaFIFO saw a key in our cache that it didn't know about, it
// can send a deletion with an unknown state. Grab the service from our
@ -146,16 +166,25 @@ func (s *ServiceController) processDelta(delta *cache.Delta) (error, bool) {
if !ok {
return fmt.Errorf("Delta contained object that wasn't a service or a deleted key: %+v", delta), notRetryable
}
service, ok = s.getService(key.Key)
cachedService, ok = s.cache.get(key.Key)
if !ok {
return fmt.Errorf("Service %s not in cache even though the watcher thought it was. Ignoring the deletion.", key), notRetryable
}
delta.Object = service
namespacedName = types.NamespacedName{service.Namespace, service.Name}
service = cachedService.service
delta.Object = cachedService.service
} else {
namespacedName.Namespace = service.Namespace
namespacedName.Name = service.Name
cachedService = s.cache.getOrCreate(namespacedName.String())
}
glog.V(2).Infof("Got new %s delta for service: %+v", delta.Type, service)
// TODO: Make this more parallel. The only things that need to serialized
// are changes to services with the same namespace and name.
// Ensure that no other goroutine will interfere with our processing of the
// service.
cachedService.mu.Lock()
defer cachedService.mu.Unlock()
// TODO: Handle added, updated, and sync differently?
switch delta.Type {
case cache.Added:
@ -163,9 +192,19 @@ func (s *ServiceController) processDelta(delta *cache.Delta) (error, bool) {
case cache.Updated:
fallthrough
case cache.Sync:
return s.createLoadBalancerIfNeeded(service)
err, retry := s.createLoadBalancerIfNeeded(namespacedName, service, cachedService.service)
if err != nil {
return err, retry
}
// Always update the cache upon success
cachedService.service = service
s.cache.set(namespacedName.String(), cachedService)
case cache.Deleted:
return s.handleDelete(service)
err := s.ensureLBDeleted(service)
if err != nil {
return err, retryable
}
s.cache.delete(namespacedName.String())
default:
glog.Errorf("Unexpected delta type: %v", delta.Type)
}
@ -174,18 +213,12 @@ func (s *ServiceController) processDelta(delta *cache.Delta) (error, bool) {
// Returns whatever error occurred along with a boolean indicator of whether it
// should be retried.
func (s *ServiceController) createLoadBalancerIfNeeded(service *api.Service) (error, bool) {
namespacedName, err := cache.MetaNamespaceKeyFunc(service)
if err != nil {
return fmt.Errorf("Couldn't generate namespaced name for service: %v", err), notRetryable
}
cachedService, cached := s.getService(namespacedName)
if cached && !needsUpdate(cachedService, service) {
func (s *ServiceController) createLoadBalancerIfNeeded(namespacedName types.NamespacedName, service, cachedService *api.Service) (error, bool) {
if cachedService != nil && !needsUpdate(cachedService, service) {
glog.Infof("LB already exists and doesn't need update for service %s", namespacedName)
return nil, notRetryable
}
if cached {
if cachedService != nil {
// If the service already exists but needs to be updated, delete it so that
// we can recreate it cleanly.
if cachedService.Spec.CreateExternalLoadBalancer {
@ -227,7 +260,7 @@ func (s *ServiceController) createLoadBalancerIfNeeded(service *api.Service) (er
// The load balancer doesn't exist yet, so create it.
publicIPstring := fmt.Sprint(service.Spec.PublicIPs)
err = s.createExternalLoadBalancer(service)
err := s.createExternalLoadBalancer(service)
if err != nil {
return fmt.Errorf("failed to create external load balancer for service %s: %v", namespacedName, err), retryable
}
@ -236,7 +269,6 @@ func (s *ServiceController) createLoadBalancerIfNeeded(service *api.Service) (er
glog.Infof("Not persisting unchanged service to registry.")
return nil, notRetryable
}
s.setService(namespacedName, service)
// If creating the load balancer succeeded, persist the updated service.
if err = s.persistUpdate(service); err != nil {
@ -245,8 +277,6 @@ func (s *ServiceController) createLoadBalancerIfNeeded(service *api.Service) (er
return nil, notRetryable
}
// TODO(a-robinson): Handle repeated failures due to ResourceVersion changes or
// the object having been deleted.
func (s *ServiceController) persistUpdate(service *api.Service) error {
var err error
for i := 0; i < clientRetryCount; i++ {
@ -254,6 +284,20 @@ func (s *ServiceController) persistUpdate(service *api.Service) error {
if err == nil {
return nil
}
// If the object no longer exists, we don't want to recreate it. Just bail
// out so that we can process the delete, which we should soon be receiving
// if we haven't already.
if errors.IsNotFound(err) {
glog.Infof("Not persisting update to service that no longer exists: %v", err)
return nil
}
// TODO: Try to resolve the conflict if the change was unrelated to load
// balancers and public IPs. For now, just rely on the fact that we'll
// also process the update that caused the resource version to change.
if errors.IsConflict(err) {
glog.Infof("Not persisting update to service that has been changed since we received it: %v", err)
return nil
}
glog.Warningf("Failed to persist updated PublicIPs to service %s after creating its external load balancer: %v",
service.Name, err)
time.Sleep(clientRetryInterval)
@ -266,7 +310,7 @@ func (s *ServiceController) createExternalLoadBalancer(service *api.Service) err
if err != nil {
return err
}
nodes, err := s.kubeClient.Nodes().List(labels.Everything())
nodes, err := s.kubeClient.Nodes().List(labels.Everything(), fields.Everything())
if err != nil {
return err
}
@ -294,24 +338,8 @@ func (s *ServiceController) createExternalLoadBalancer(service *api.Service) err
return nil
}
// Returns whatever error occurred along with a boolean indicator of whether it
// should be retried.
func (s *ServiceController) handleDelete(service *api.Service) (error, bool) {
if err := s.ensureLBDeleted(service); err != nil {
return err, retryable
}
namespacedName, err := cache.MetaNamespaceKeyFunc(service)
if err != nil {
// This is panic-worthy, since the queue shouldn't have been able to
// handle the service if it couldn't generate a name for it.
return fmt.Errorf("Couldn't generate namespaced name for service: %v", err), notRetryable
}
s.deleteService(namespacedName)
return nil, notRetryable
}
// Ensures that the load balancer associated with the given service is deleted,
// doing the deletion if necessary.
// doing the deletion if necessary. Should always be retried upon failure.
func (s *ServiceController) ensureLBDeleted(service *api.Service) error {
// This is only needed because not all delete load balancer implementations
// are currently idempotent to the LB not existing.
@ -327,9 +355,9 @@ func (s *ServiceController) ensureLBDeleted(service *api.Service) error {
return nil
}
// listKeys implements the interface required by DeltaFIFO to list the keys we
// ListKeys implements the interface required by DeltaFIFO to list the keys we
// already know about.
func (s *ServiceController) listKeys() []string {
func (s *serviceCache) ListKeys() []string {
s.mu.Lock()
defer s.mu.Unlock()
keys := make([]string, 0, len(s.serviceMap))
@ -339,20 +367,31 @@ func (s *ServiceController) listKeys() []string {
return keys
}
func (s *ServiceController) getService(serviceName string) (*api.Service, bool) {
func (s *serviceCache) get(serviceName string) (*cachedService, bool) {
s.mu.Lock()
defer s.mu.Unlock()
info, ok := s.serviceMap[serviceName]
return info, ok
service, ok := s.serviceMap[serviceName]
return service, ok
}
func (s *ServiceController) setService(serviceName string, info *api.Service) {
func (s *serviceCache) getOrCreate(serviceName string) *cachedService {
s.mu.Lock()
defer s.mu.Unlock()
s.serviceMap[serviceName] = info
service, ok := s.serviceMap[serviceName]
if !ok {
service = &cachedService{}
s.serviceMap[serviceName] = service
}
return service
}
func (s *ServiceController) deleteService(serviceName string) {
func (s *serviceCache) set(serviceName string, service *cachedService) {
s.mu.Lock()
defer s.mu.Unlock()
s.serviceMap[serviceName] = service
}
func (s *serviceCache) delete(serviceName string) {
s.mu.Lock()
defer s.mu.Unlock()
delete(s.serviceMap, serviceName)
@ -379,10 +418,8 @@ func needsUpdate(oldService *api.Service, newService *api.Service) bool {
return false
}
// TODO: Use a shorter name that's less likely to be longer than cloud
// providers' length limits.
func (s *ServiceController) loadBalancerName(service *api.Service) string {
return s.cloud.GetLoadBalancerName(s.clusterName, service.Namespace, service.Name)
return cloudprovider.GetLoadBalancerName(s.clusterName, service.Namespace, service.Name)
}
func getTCPPorts(service *api.Service) ([]int, error) {
@ -411,13 +448,10 @@ func portsEqual(x, y *api.Service) bool {
if len(xPorts) != len(yPorts) {
return false
}
// Use a map for comparison since port slices aren't necessarily sorted.
xPortMap := make(map[int]bool)
for _, xPort := range xPorts {
xPortMap[xPort] = true
}
for _, yPort := range yPorts {
if !xPortMap[yPort] {
sort.Ints(xPorts)
sort.Ints(yPorts)
for i := range xPorts {
if xPorts[i] != yPorts[i] {
return false
}
}

3
pkg/cloudprovider/servicecontroller/servicecontroller_test.go
View File

@ -22,6 +22,7 @@ import (
"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
"github.com/GoogleCloudPlatform/kubernetes/pkg/client/testclient"
fake_cloud "github.com/GoogleCloudPlatform/kubernetes/pkg/cloudprovider/fake"
"github.com/GoogleCloudPlatform/kubernetes/pkg/types"
)
const region = "us-central"
@ -89,7 +90,7 @@ func TestCreateExternalLoadBalancer(t *testing.T) {
controller.init()
cloud.Calls = nil // ignore any cloud calls made in init()
client.Actions = nil // ignore any client calls made in init()
err, _ := controller.createLoadBalancerIfNeeded(item.service)
err, _ := controller.createLoadBalancerIfNeeded(types.NamespacedName{"foo", "bar"}, item.service, nil)
if !item.expectErr && err != nil {
t.Errorf("unexpected error: %v", err)
} else if item.expectErr && err == nil {