我使用tiup启动或停止tidb节点是可以的，这能说明tiup中控机和tidb节点间的通信是正常的吗？
在tidb的日志中， 我能看到下面的错误：
[2021/07/29 07:52:07.921 +08:00] [INFO] [grpclogger.go:77] [“ClientConn switching balancer to “pick_first””] [system=grpc] [grpc_log=true]
[2021/07/29 07:52:25.942 +08:00] [INFO] [grpclogger.go:77] [“ccResolverWrapper: sending new addresses to cc: [{http://10.10.10.208:2379 0 } {http://10.10.10.209:2379 0 } {http://10.10.10.207:2379 0 }]”] [system=grpc] [grpc_log=true]
[2021/07/29 07:52:30.634 +08:00] [WARN] [grpclogger.go:85] [“grpc: Server.Serve failed to create ServerTransport: connection error: desc = “transport: http2Server.HandleStreams failed to receive the preface from client: EOF””] [system=grpc] [grpc_log=true]
[2021/07/29 07:52:35.014 +08:00] [INFO] [grpclogger.go:77] [“ccResolverWrapper: sending new addresses to cc: [{http://10.10.10.208:2379 0 } {http://10.10.10.209:2379 0 } {http://10.10.10.207:2379 0 }]”] [system=grpc] [grpc_log=true]
[2021/07/29 07:52:55.943 +08:00] [INFO] [grpclogger.go:77] [“ccResolverWrapper: sending new addresses to cc: [{http://10.10.10.208:2379 0 } {http://10.10.10.209:2379 0 } {http://10.10.10.207:2379 0 }]”] [system=grpc] [grpc_log=true]
[2021/07/29 07:53:00.635 +08:00] [WARN] [grpclogger.go:85] [“grpc: Server.Serve failed to create ServerTransport: connection error: desc = “transport: http2Server.HandleStreams failed to receive the preface from client: EOF””] [system=grpc] [grpc_log=true]
[2021/07/29 07:53:05.014 +08:00] [INFO] [grpclogger.go:77] [“ccResolverWrapper: sending new addresses to cc: [{http://10.10.10.208:2379 0 } {http://10.10.10.209:2379 0 } {http://10.10.10.207:2379 0 }]”] [system=grpc] [grpc_log=true]
[2021/07/29 07:53:25.945 +08:00] [INFO] [grpclogger.go:77] [“ccResolverWrapper: sending new addresses to cc: [{http://10.10.10.208:2379 0 } {http://10.10.10.209:2379 0 } {http://10.10.10.207:2379 0 }]”] [system=grpc] [grpc_log=true]
[2021/07/29 07:53:30.635 +08:00] [WARN] [grpclogger.go:85] [“grpc: Server.Serve failed to create ServerTransport: connection error: desc = “transport: http2Server.HandleStreams failed to receive the preface from client: EOF””] [system=grpc] [grpc_log=true]
[2021/07/29 07:53:35.016 +08:00] [INFO] [grpclogger.go:77] [“ccResolverWrapper: sending new addresses to cc: [{http://10.10.10.208:2379 0 } {http://10.10.10.209:2379 0 } {http://10.10.10.207:2379 0 }]”] [system=grpc] [grpc_log=true]
[2021/07/29 07:53:55.946 +08:00] [INFO] [grpclogger.go:77] [“ccResolverWrapper: sending new addresses to cc: [{http://10.10.10.208:2379 0 } {http://10.10.10.209:2379 0 } {http://10.10.10.207:2379 0 }]”] [system=grpc] [grpc_log=true]
[2021/07/29 07:54:00.635 +08:00] [WARN] [grpclogger.go:85] [“grpc: Server.Serve failed to create ServerTransport: connection error: desc = “transport: http2Server.HandleStreams failed to receive the preface from client: EOF””] [system=grpc] [grpc_log=true]
[2021/07/29 07:54:05.017 +08:00] [INFO] [grpclogger.go:77] [“ccResolverWrapper: sending new addresses to cc: [{http://10.10.10.208:2379 0 } {http://10.10.10.209:2379 0 } {http://10.10.10.207:2379 0 }]”] [system=grpc] [grpc_log=true]
[2021/07/29 07:54:25.948 +08:00] [INFO] [grpclogger.go:77] [“ccResolverWrapper: sending new addresses to cc: [{http://10.10.10.208:2379 0 } {http://10.10.10.209:2379 0 } {http://10.10.10.207:2379 0 }]”] [system=grpc] [grpc_log=true]
[2021/07/29 07:54:30.634 +08:00] [WARN] [grpclogger.go:85] [“grpc: Server.Serve failed to create ServerTransport: connection error: desc = “transport: http2Server.HandleStreams failed to receive the preface from client: EOF””] [system=grpc] [grpc_log=true]
[2021/07/29 07:54:35.017 +08:00] [INFO] [grpclogger.go:77] [“ccResolverWrapper: sending new addresses to cc: [{http://10.10.10.208:2379 0 } {http://10.10.10.209:2379 0 } {http://10.10.10.207:2379 0 }]”] [system=grpc] [grpc_log=true]