OpenTSDB: Init script specifies the tsd cachedir from the environment variable HTTP_CACHE_DIR_PREFIX. (https://rbcommons.com/s/pepperdata/r/3749)
- OpenTSDB cache directory name is composed of $HTTP_CACHE_DIR_PREFIX and the
int script filename. - Command line cache dir overrides just empty cache dir
configuration. If the configured cache dir is not empty and different from the
command line one, tsdb throws exception and fails to run.