etcdserver: add --max-request-bytes flag

etcdserver/server.go

@@ -83,6 +83,8 @@ const (
 
 	// maxPendingRevokes is the maximum number of outstanding expired lease revocations.
 	maxPendingRevokes = 16
+
+	recommendedMaxRequestBytes = 10 * 1024 * 1024
 )
 
 var (
@@ -259,6 +261,10 @@ func NewServer(cfg *ServerConfig) (srv *EtcdServer, err error) {
 		cl *membership.RaftCluster
 	)
 
+	if cfg.MaxRequestBytes > recommendedMaxRequestBytes {
+		plog.Warningf("MaxRequestBytes %v exceeds maximum recommended size %v", cfg.MaxRequestBytes, recommendedMaxRequestBytes)
+	}
+
 	if terr := fileutil.TouchDirAll(cfg.DataDir); terr != nil {
 		return nil, fmt.Errorf("cannot access data directory: %v", terr)
 	}