https://knowledge.broadcom.com/external/article?articleId=105772#/
The above KB helped resolving an EM startup issue.
Concern is , what are the advantages of having nio active? What features does it has to offer?
transport.enable.nio=
Release : 10.7.0
Component : Introscope
No major difference using between Java IO and Java NIO
From APM Development:
"Disabling NIO will switch back to the previous classic socket operations to revert to the polling architecture, there is no loss of functionality.
The main difference between Java IO and Java NIO is IO is stream oriented where caching is not there while NIO is buffer oriented and uses caching to read data and has additional flexibility due the buffering. Apart from flexibility you may have other overheads of verification before data processing and overwriting dangers. Once the data is read, it does not make any difference in what you do with it and how you handle it. Hence, using IO/NIO should not make any other difference