No network encryption support yet but there is a patch up at https://issues.apache.org/jira/browse/FLUME-997
for this functionality. You are welcome to take a look and provide any comments. Not sure what you mean by #2, you would have to share more about your requirements / use case.
I have to install Flume and ensure that data transfer from Agent to Collector to Sink is secure enough. I noticed that some changes related ssl in FLUME-13 and that is very old. I see some discussion at http://search-hadoop.com/m/Unjdh2ovsNE/v=plain
but I dont know if there is any update after.
I request someone, if possible to give a qualified answer to
1. Is encryption possible in the Agent to Collector to Sink communication.
2. If not, does that mean RPC communication is secure enough if not encrypted.
3. Any pointers for security related design.
Thanks very much for reading this much and appreciate someone's insight.