Edit logs are saved on Journal daemon. When NameNode starts, it loads the latest image file and then streams the edit logs from an active Journal daemon.
Currently we are using http to transfer edit files between two journal daemons/nodes or between a journal daemon and a NameNode. To get edit file from Journal daemon, the NameNode has to download it first and then read it from the disk.
To avoid the slow start-up time, NameNode should be enhance to read the http data stream and update its in memory name space instead of saving the streamed data on disk first.