subscriber keep connected to the balancer

weed/mq/sub_coordinator/consumer_group.go

@@ -5,6 +5,7 @@ import (
 	"github.com/seaweedfs/seaweedfs/weed/mq/pub_balancer"
 	"github.com/seaweedfs/seaweedfs/weed/mq/topic"
 	"github.com/seaweedfs/seaweedfs/weed/pb/mq_pb"
+	"time"
 )
 
 type ConsumerGroupInstance struct {
@@ -16,7 +17,8 @@ type ConsumerGroupInstance struct {
 type ConsumerGroup struct {
 	// map a consumer group instance id to a consumer group instance
 	ConsumerGroupInstances cmap.ConcurrentMap[string, *ConsumerGroupInstance]
-	mapping                *PartitionConsumerMapping
+	mapping        *PartitionConsumerMapping
+	reBalanceTimer *time.Timer
 }
 
 func NewConsumerGroup() *ConsumerGroup {
@@ -33,10 +35,30 @@ func NewConsumerGroupInstance(instanceId string) *ConsumerGroupInstance {
 	}
 }
 func (cg *ConsumerGroup) OnAddConsumerGroupInstance(consumerGroupInstance string, topic *mq_pb.Topic) {
+	cg.onConsumerGroupInstanceChange()
 }
 func (cg *ConsumerGroup) OnRemoveConsumerGroupInstance(consumerGroupInstance string, topic *mq_pb.Topic) {
+	cg.onConsumerGroupInstanceChange()
+}
 
+func (cg *ConsumerGroup) onConsumerGroupInstanceChange(){
+	if cg.reBalanceTimer != nil {
+		cg.reBalanceTimer.Stop()
+		cg.reBalanceTimer = nil
+	}
+	cg.reBalanceTimer = time.AfterFunc(5*time.Second, func() {
+		cg.Rebalance()
+		cg.reBalanceTimer = nil
+	})
 }
 func (cg *ConsumerGroup) OnPartitionListChange() {
-
+	if cg.reBalanceTimer != nil {
+		cg.reBalanceTimer.Stop()
+		cg.reBalanceTimer = nil
+	}
+	cg.Rebalance()
+}
+
+func (cg *ConsumerGroup) Rebalance() {
+	println("rebalance...")
 }