Root logger is now hijacked by default, to disable this behavior set CELERYD_HIJACK_ROOT_LOGGER = False

celery/conf.py

@@ -66,7 +66,7 @@ _DEFAULTS = {
     "CELERYD_LOG_COLOR": False,
     "CELERYD_LOG_LEVEL": "WARN",
     "CELERYD_LOG_FILE": None,                       # stderr
-    "CELERYD_FORCE_HIJACK_ROOT_LOGGER": False,
+    "CELERYD_HIJACK_ROOT_LOGGER": True,
     "CELERYBEAT_SCHEDULER": "celery.beat.PersistentScheduler",
     "CELERYBEAT_SCHEDULE": {},
     "CELERYD_STATE_DB": None,
@@ -186,7 +186,7 @@ def prepare(m, source=settings, defaults=_DEFAULTS):
                             compat=["CELERYD_DAEMON_LOG_LEVEL"])
     if not isinstance(m.CELERYD_LOG_LEVEL, int):
         m.CELERYD_LOG_LEVEL = LOG_LEVELS[m.CELERYD_LOG_LEVEL.upper()]
-    m.CELERYD_FORCE_HIJACK_ROOT_LOGGER = _get("CELERYD_FORCE_HIJACK_ROOT_LOGGER")
+    m.CELERYD_HIJACK_ROOT_LOGGER = _get("CELERYD_HIJACK_ROOT_LOGGER")
     m.CELERYD_STATE_DB = _get("CELERYD_STATE_DB")
     m.CELERYD_CONCURRENCY = _get("CELERYD_CONCURRENCY")
     m.CELERYD_PREFETCH_MULTIPLIER = _get("CELERYD_PREFETCH_MULTIPLIER")

celery/log.py

@@ -84,7 +84,7 @@ def setup_logging_subsystem(loglevel=conf.CELERYD_LOG_LEVEL, logfile=None,
         if not receivers:
             root = logging.getLogger()
 
-            if conf.CELERYD_FORCE_HIJACK_ROOT_LOGGER:
+            if conf.CELERYD_HIJACK_ROOT_LOGGER:
                 root.handlers = []
 
             mp = mputil.get_logger()
@@ -126,7 +126,7 @@ def setup_logger(loglevel=conf.CELERYD_LOG_LEVEL, logfile=None,
     Returns logger object.
 
     """
-    if not root or conf.CELERYD_FORCE_HIJACK_ROOT_LOGGER:
+    if not root or conf.CELERYD_HIJACK_ROOT_LOGGER:
         return _setup_logger(get_default_logger(loglevel, name),
                              logfile, format, colorize, **kwargs)
     setup_logging_subsystem(loglevel, logfile, format, colorize, **kwargs)

celery/tests/config.py

@@ -2,6 +2,8 @@ import os
 
 BROKER_BACKEND = "memory"
 
+#: Don't want log output when running suite.
+CELERYD_HIJACK_ROOT_LOGGER = False
 
 CELERY_RESULT_BACKEND = "database"
 CELERY_RESULT_DBURI = "sqlite:///test.db"