Add in utility to detect and delete any NRG orphans.

Signed-off-by: Derek Collison <derek@nats.io>

server/jetstream_cluster.go

@@ -1167,6 +1167,65 @@ func (js *jetStream) checkForOrphans() {
 	}
 }
 
+// Check and delete any orphans we may come across.
+func (s *Server) checkForNRGOrphans() {
+	js, cc := s.getJetStreamCluster()
+	if js == nil || cc == nil || js.isMetaRecovering() {
+		// No cluster means no NRGs. Also return if still recovering.
+		return
+	}
+
+	// Track which assets R>1 should be on this server.
+	nrgMap := make(map[string]struct{})
+	trackGroup := func(rg *raftGroup) {
+		// If R>1 track this as a legit NRG.
+		if rg.node != nil {
+			nrgMap[rg.Name] = struct{}{}
+		}
+	}
+	// Register our meta.
+	js.mu.RLock()
+	meta := cc.meta
+	if meta == nil {
+		js.mu.RUnlock()
+		// Bail with no meta node.
+		return
+	}
+
+	ourID := meta.ID()
+	nrgMap[meta.Group()] = struct{}{}
+
+	// Collect all valid groups from our assignments.
+	for _, asa := range cc.streams {
+		for _, sa := range asa {
+			if sa.Group.isMember(ourID) && sa.Restore == nil {
+				trackGroup(sa.Group)
+				for _, ca := range sa.consumers {
+					if ca.Group.isMember(ourID) {
+						trackGroup(ca.Group)
+					}
+				}
+			}
+		}
+	}
+	js.mu.RUnlock()
+
+	// Check NRGs that are running.
+	var needDelete []RaftNode
+	s.rnMu.RLock()
+	for name, n := range s.raftNodes {
+		if _, ok := nrgMap[name]; !ok {
+			needDelete = append(needDelete, n)
+		}
+	}
+	s.rnMu.RUnlock()
+
+	for _, n := range needDelete {
+		s.Warnf("Detected orphaned NRG %q, will cleanup", n.Group())
+		n.Delete()
+	}
+}
+
 func (js *jetStream) monitorCluster() {
 	s, n := js.server(), js.getMetaGroup()
 	qch, rqch, lch, aq := js.clusterQuitC(), n.QuitC(), n.LeadChangeC(), n.ApplyQ()
@@ -1197,6 +1256,8 @@ func (js *jetStream) monitorCluster() {
 		if hs := s.healthz(nil); hs.Error != _EMPTY_ {
 			s.Warnf("%v", hs.Error)
 		}
+		// Also check for orphaned NRGs.
+		s.checkForNRGOrphans()
 	}
 
 	var (
@@ -1277,7 +1338,6 @@ func (js *jetStream) monitorCluster() {
 					go checkHealth()
 					continue
 				}
-				// FIXME(dlc) - Deal with errors.
 				if didSnap, didStreamRemoval, didConsumerRemoval, err := js.applyMetaEntries(ce.Entries, ru); err == nil {
 					_, nb := n.Applied(ce.Index)
 					if js.hasPeerEntries(ce.Entries) || didStreamRemoval || (didSnap && !isLeader) {
@@ -1288,6 +1348,8 @@ func (js *jetStream) monitorCluster() {
 						doSnapshot()
 					}
 					ce.ReturnToPool()
+				} else {
+					s.Warnf("Error applying JetStream cluster entries: %v", err)
 				}
 			}
 			aq.recycle(&ces)
@@ -2037,6 +2099,15 @@ func (mset *stream) removeNode() {
 	}
 }
 
+func (mset *stream) clearRaftNode() {
+	if mset == nil {
+		return
+	}
+	mset.mu.Lock()
+	defer mset.mu.Unlock()
+	mset.node = nil
+}
+
 // Helper function to generate peer info.
 // lists and sets for old and new.
 func genPeerInfo(peers []string, split int) (newPeers, oldPeers []string, newPeerSet, oldPeerSet map[string]bool) {