Cloned from launchpad blueprint https://blueprints.launchpad.net/nova/+spec/config-reload-no-restart. Description: Problem: We shouldn't need to restart the service just to reload some simple config options. But we also can't hope to convert all config at once. Note, we are building on existing support here: https://blueprints.launchpad.net/oslo/+spec/cfg-reload-config-files Suggested route: * mark options we can reload without restart with "can_update_without_restart=True", default to false * add a new param to reload config: without_restart=True * if True, we only update config values that are marked with can_update_without_restart=True, and log a warning for any other changes that are spotted * we can then convert a few easy options to can_update_without_restart=True * other will be able to follow the pattern We can trigger the reload using a file watcher, using something similar to: https://pypi.python.org/pypi/watchdog Specification URL (additional information): None