From 9052eddaf602fbbcfaaab226e290d593b5aaa225 Mon Sep 17 00:00:00 2001
From: Tim Hockin <thockin@google.com>
Date: Sat, 7 May 2016 21:23:50 -0700
Subject: [PATCH] Don't delete affinity when endpoints are empty

This only affects the userspace kube-proxy.
---
 pkg/proxy/userspace/loadbalancer.go |  1 +
 pkg/proxy/userspace/proxier.go      |  1 +
 pkg/proxy/userspace/roundrobin.go   | 14 +++++++++++++-
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/pkg/proxy/userspace/loadbalancer.go b/pkg/proxy/userspace/loadbalancer.go
index f32f05fc8a1..711c9f1d5a5 100644
--- a/pkg/proxy/userspace/loadbalancer.go
+++ b/pkg/proxy/userspace/loadbalancer.go
@@ -29,5 +29,6 @@ type LoadBalancer interface {
 	// service-port and source address.
 	NextEndpoint(service proxy.ServicePortName, srcAddr net.Addr) (string, error)
 	NewService(service proxy.ServicePortName, sessionAffinityType api.ServiceAffinity, stickyMaxAgeMinutes int) error
+	DeleteService(service proxy.ServicePortName)
 	CleanupStaleStickySessions(service proxy.ServicePortName)
 }
diff --git a/pkg/proxy/userspace/proxier.go b/pkg/proxy/userspace/proxier.go
index 0ee5185943c..fb5d00e1eb6 100644
--- a/pkg/proxy/userspace/proxier.go
+++ b/pkg/proxy/userspace/proxier.go
@@ -447,6 +447,7 @@ func (proxier *Proxier) OnServiceUpdate(services []api.Service) {
 			if err != nil {
 				glog.Errorf("Failed to stop service %q: %v", name, err)
 			}
+			proxier.loadBalancer.DeleteService(name)
 		}
 	}
 }
diff --git a/pkg/proxy/userspace/roundrobin.go b/pkg/proxy/userspace/roundrobin.go
index 86a93e25618..fa4735c5a7c 100644
--- a/pkg/proxy/userspace/roundrobin.go
+++ b/pkg/proxy/userspace/roundrobin.go
@@ -82,6 +82,7 @@ func NewLoadBalancerRR() *LoadBalancerRR {
 }
 
 func (lb *LoadBalancerRR) NewService(svcPort proxy.ServicePortName, affinityType api.ServiceAffinity, ttlMinutes int) error {
+	glog.V(4).Infof("LoadBalancerRR NewService %q", svcPort)
 	lb.lock.Lock()
 	defer lb.lock.Unlock()
 	lb.newServiceInternal(svcPort, affinityType, ttlMinutes)
@@ -103,6 +104,13 @@ func (lb *LoadBalancerRR) newServiceInternal(svcPort proxy.ServicePortName, affi
 	return lb.services[svcPort]
 }
 
+func (lb *LoadBalancerRR) DeleteService(svcPort proxy.ServicePortName) {
+	glog.V(4).Infof("LoadBalancerRR DeleteService %q", svcPort)
+	lb.lock.Lock()
+	defer lb.lock.Unlock()
+	delete(lb.services, svcPort)
+}
+
 // return true if this service is using some form of session affinity.
 func isSessionAffinity(affinity *affinityPolicy) bool {
 	// Should never be empty string, but checking for it to be safe.
@@ -279,7 +287,11 @@ func (lb *LoadBalancerRR) OnEndpointsUpdate(allEndpoints []api.Endpoints) {
 	for k := range lb.services {
 		if _, exists := registeredEndpoints[k]; !exists {
 			glog.V(2).Infof("LoadBalancerRR: Removing endpoints for %s", k)
-			delete(lb.services, k)
+			// Reset but don't delete.
+			state := lb.services[k]
+			state.endpoints = []string{}
+			state.index = 0
+			state.affinity.affinityMap = map[string]*affinityState{}
 		}
 	}
 }