Warning messages when redis-server is started on Linux.

[robertnishihara]

Warning messages when redis-server is started on Linux.

[atumanov]

I think there's a more general underlying question of what to do with stdio for all Ray system components. We could have something like a RAY_LOG_DIR where logs are aggregated for all system components including Redis. All stdio can be redirected there. User shouldn't see any of this. At the same time, they should be able to access these messages if they want to. So best practice is to store it in a per-daemon log and log-rotate them (to keep the space per log capped).

[robertnishihara]

Agreed. There is a deeper question about how to handle output from all the different processes.

[robertnishihara]

As a stopgap, this commit redirects the redis-server output to /dev/null. This is not a long term solution.. 2d0d041

[robertnishihara]

We're suppressing the error for now (by always redirecting redis output to a file). We may want to look into this more in the future to improve redis performance..