Resolution: If the EMS server is started by an application and the parent application does not handle the child process STDERR and STDOUT. If configured, the tracing to write to STDERR or STDOUT, then when the STDERR and STDOUT buffer is full, the EMS sever would hang at the write() system call.
The resolution is to fix the parent process on handling child process STDERR and STDOUT. Alternatively, on "FIX", you can start EMS directly from the command line and redirect the STDERR and STDOUT to /dev/null .