Android TCP does not flush until socket is closed [duplicate]

Answer 1

Since these are short messages (< MSS), I guess the stack may be implementing Nagle's algorithm. Is the server doing some kind of delayed ACKs? If possible you should capture a trace and see if there are pending acknowledgements from the other side.

In either case, TCP_NODELAY should help.

Answer 2

I suspect you are reading lines at the consumer, but you aren't writing lines, so the consumer blocks until it gets EOS and delivers one big line. Add line terminators when sending as necessary.