Merge pull request #8840 from gyuho/health-balancer

*: refactor clientv3 balancer, upgrade gRPC to v1.7.2

clientv3/client.go

@@ -121,6 +121,19 @@ func (c *Client) SetEndpoints(eps ...string) {
 	c.cfg.Endpoints = eps
 	c.mu.Unlock()
 	c.balancer.updateAddrs(eps...)
+
+	// updating notifyCh can trigger new connections,
+	// need update addrs if all connections are down
+	// or addrs does not include pinAddr.
+	c.balancer.mu.RLock()
+	update := !hasAddr(c.balancer.addrs, c.balancer.pinAddr)
+	c.balancer.mu.RUnlock()
+	if update {
+		select {
+		case c.balancer.updateAddrsC <- notifyNext:
+		case <-c.balancer.stopc:
+		}
+	}
 }
 
 // Sync synchronizes client's endpoints with the known endpoints from the etcd membership.
@@ -378,9 +391,9 @@ func newClient(cfg *Config) (*Client, error) {
 		client.Password = cfg.Password
 	}
 
-	sb := newSimpleBalancer(cfg.Endpoints)
-	hc := func(ep string) (bool, error) { return grpcHealthCheck(client, ep) }
-	client.balancer = newHealthBalancer(sb, cfg.DialTimeout, hc)
+	client.balancer = newHealthBalancer(cfg.Endpoints, cfg.DialTimeout, func(ep string) (bool, error) {
+		return grpcHealthCheck(client, ep)
+	})
 
 	// use Endpoints[0] so that for https:// without any tls config given, then
 	// grpc will assume the certificate server name is the endpoint host.