Merge .out and .err worker log files

Hi, guys! Currently, there are .out and .err worker files in our /tmp/ray/session_latest/logs , and we are planning to combine those two files to .log file to
reduce number of files
help people looking at the whole logs within a single file

This means we will remove files such as


and it will become


This also means logs that are streamed to the driver will always be emitted to stderr or stdout only (currently, we emit .err file to stderr and .out file to stdout).

Since this can be breaking changes for some people, I’d like to hear if there are any concerns about this or other suggestions.


01000000 means job id?

Yes. This log name will be more clearly explained in our documentation soon.