Fix unregister node info has no channel (#5699)

Signed-off-by: NCongqi Xia <congqi.xia@zilliz.com>

internal/dataservice/cluster.go

@@ -170,7 +170,9 @@ func (c *cluster) register(n *datapb.DataNodeInfo) {
 	c.dataManager.register(n)
 	cNodes, chanBuffer := c.dataManager.getDataNodes(true)
 	var rets []*datapb.DataNodeInfo
+	log.Debug("before register policy applied", zap.Any("n.Channels", n.Channels), zap.Any("buffer", chanBuffer))
 	rets, chanBuffer = c.registerPolicy.apply(cNodes, n, chanBuffer)
+	log.Debug("after register policy applied", zap.Any("ret", rets), zap.Any("buffer", chanBuffer))
 	c.dataManager.updateDataNodes(rets, chanBuffer)
 	rets = c.watch(rets)
 	c.dataManager.updateDataNodes(rets, chanBuffer)
@@ -179,9 +181,14 @@ func (c *cluster) register(n *datapb.DataNodeInfo) {
 func (c *cluster) unregister(n *datapb.DataNodeInfo) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
+
 	c.sessionManager.releaseSession(n.Address)
-	c.dataManager.unregister(n)
+	oldNode := c.dataManager.unregister(n)
+	if oldNode != nil {
+		n = oldNode
+	}
 	cNodes, chanBuffer := c.dataManager.getDataNodes(true)
+	log.Debug("before unregister policy applied", zap.Any("n.Channels", n.Channels), zap.Any("buffer", chanBuffer))
 	var rets []*datapb.DataNodeInfo
 	if len(cNodes) == 0 {
 		for _, chStat := range n.Channels {
@@ -191,6 +198,7 @@ func (c *cluster) unregister(n *datapb.DataNodeInfo) {
 	} else {
 		rets = c.unregisterPolicy.apply(cNodes, n)
 	}
+	log.Debug("after register policy applied", zap.Any("ret", rets), zap.Any("buffer", chanBuffer))
 	c.dataManager.updateDataNodes(rets, chanBuffer)
 	rets = c.watch(rets)
 	c.dataManager.updateDataNodes(rets, chanBuffer)

internal/dataservice/cluster_data_manager.go

@@ -158,13 +158,14 @@ func (c *clusterNodeManager) register(n *datapb.DataNodeInfo) {
 	c.updateMetrics()
 }
 
-func (c *clusterNodeManager) unregister(n *datapb.DataNodeInfo) {
+func (c *clusterNodeManager) unregister(n *datapb.DataNodeInfo) *datapb.DataNodeInfo {
 	node, ok := c.dataNodes[n.Address]
 	if !ok {
-		return
+		return nil
 	}
 	node.status = offline
 	c.updateMetrics()
+	return node.info
 }
 
 func (c *clusterNodeManager) updateMetrics() {