From 549b77ca2dabb37e03682e3320256845f712cac5 Mon Sep 17 00:00:00 2001
From: Derek Collison <derek@nats.io>
Date: Tue, 6 Dec 2022 15:07:46 -0800
Subject: [PATCH] Ensure that ephemeral consumers that are deleted on startup
 properly are removed from the system.

Signed-off-by: Derek Collison <derek@nats.io>
---
 server/consumer.go                 |  8 +---
 server/jetstream_cluster_3_test.go | 64 +++++++++++++++++++++++++++++-
 2 files changed, 65 insertions(+), 7 deletions(-)

diff --git a/server/consumer.go b/server/consumer.go
index 53769e7f..75d41877 100644
--- a/server/consumer.go
+++ b/server/consumer.go
@@ -1353,7 +1353,6 @@ func (o *consumer) deleteNotActive() {
 			// Check to make sure we went away.
 			// Don't think this needs to be a monitored go routine.
 			go func() {
-				var fs bool
 				ticker := time.NewTicker(time.Second)
 				defer ticker.Stop()
 				for range ticker.C {
@@ -1361,11 +1360,8 @@ func (o *consumer) deleteNotActive() {
 					ca := js.consumerAssignment(acc, stream, name)
 					js.mu.RUnlock()
 					if ca != nil {
-						if fs {
-							s.Warnf("Consumer assignment not cleaned up, retrying")
-							meta.ForwardProposal(removeEntry)
-						}
-						fs = true
+						s.Warnf("Consumer assignment for '%s > %s > %s' not cleaned up, retrying", acc, stream, name)
+						meta.ForwardProposal(removeEntry)
 					} else {
 						return
 					}
diff --git a/server/jetstream_cluster_3_test.go b/server/jetstream_cluster_3_test.go
index 79633d5b..5e19cd5f 100644
--- a/server/jetstream_cluster_3_test.go
+++ b/server/jetstream_cluster_3_test.go
@@ -1635,5 +1635,67 @@ func TestJetStreamParallelConsumerCreation(t *testing.T) {
 	if len(rg) != expected {
 		t.Fatalf("Expected only %d distinct raft groups for all servers, go %d", expected, len(rg))
 	}
-
+}
+
+func TestJetStreamGhostEphemeralsAfterRestart(t *testing.T) {
+	c := createJetStreamClusterExplicit(t, "R3S", 3)
+	defer c.shutdown()
+
+	nc, js := jsClientConnect(t, c.randomServer())
+	defer nc.Close()
+
+	_, err := js.AddStream(&nats.StreamConfig{
+		Name:     "TEST",
+		Subjects: []string{"foo"},
+		Replicas: 3,
+	})
+	require_NoError(t, err)
+
+	// Add in 100 memory based ephemerals.
+	for i := 0; i < 100; i++ {
+		_, err = js.AddConsumer("TEST", &nats.ConsumerConfig{
+			Replicas:          1,
+			InactiveThreshold: time.Second,
+			MemoryStorage:     true,
+		})
+		require_NoError(t, err)
+	}
+
+	// Grab random server.
+	rs := c.randomServer()
+	// Now shutdown cluster.
+	c.stopAll()
+
+	// Let the consumers all expire.
+	time.Sleep(2 * time.Second)
+
+	// Restart first and wait so that we know it will try cleanup without a metaleader.
+	c.restartServer(rs)
+	time.Sleep(time.Second)
+
+	c.restartAll()
+	c.waitOnLeader()
+	c.waitOnStreamLeader(globalAccountName, "TEST")
+
+	nc, _ = jsClientConnect(t, c.randomServer())
+	defer nc.Close()
+
+	subj := fmt.Sprintf(JSApiConsumerListT, "TEST")
+	checkFor(t, 5*time.Second, 200*time.Millisecond, func() error {
+		m, err := nc.Request(subj, nil, time.Second)
+		if err != nil {
+			return err
+		}
+		var resp JSApiConsumerListResponse
+		err = json.Unmarshal(m.Data, &resp)
+		require_NoError(t, err)
+		if len(resp.Consumers) != 0 {
+			return fmt.Errorf("Still have %d consumers", len(resp.Consumers))
+		}
+		if len(resp.Missing) != 0 {
+			return fmt.Errorf("Still have %d missing consumers", len(resp.Missing))
+		}
+
+		return nil
+	})
 }