Send all logging to the root logger instead of per-module loggers.

This undoes the effect of
http://github.com/facebook/tornado/commit/e391fd289ed085671344504cc5b1fa84f5a3c774

Per-module loggers are problematic because only the top-level convenience
logging.{error,warning,...} functions configure logging on-demand, so
an app that only uses per-module loggers will produce no output except
"no handlers found for logger X".  Since tornado.ioloop swallows and logs
all exceptions, this makes it too hard to tell what's going on for apps
that do not configure logging explicitly.

Instead of setting log levels on individual module's loggers,
logging.Handler.addFilter can be used with a filter that examines
the module attribute of the log record.

tornado/auth.py

@@ -58,8 +58,6 @@ def _on_auth(self, user):
 import urlparse
 import uuid
 
-_log = logging.getLogger("tornado.auth")
-
 class OpenIdMixin(object):
     """Abstract implementation of OpenID and Attribute Exchange.
 
@@ -146,7 +144,7 @@ def _openid_args(self, callback_uri, ax_attrs=[], oauth_scope=None):
 
     def _on_authentication_verified(self, callback, response):
         if response.error or u"is_valid:true" not in response.body:
-            _log.warning("Invalid OpenID response: %s", response.error or
+            logging.warning("Invalid OpenID response: %s", response.error or
                             response.body)
             callback(None)
             return
@@ -233,12 +231,12 @@ def get_authenticated_user(self, callback):
         request_key = self.get_argument("oauth_token")
         request_cookie = self.get_cookie("_oauth_request_token")
         if not request_cookie:
-            _log.warning("Missing OAuth request token cookie")
+            logging.warning("Missing OAuth request token cookie")
             callback(None)
             return
         cookie_key, cookie_secret = request_cookie.split("|")
         if cookie_key != request_key:
-            _log.warning("Request token does not match cookie")
+            logging.warning("Request token does not match cookie")
             callback(None)
             return
         token = dict(key=cookie_key, secret=cookie_secret)
@@ -290,7 +288,7 @@ def _oauth_access_token_url(self, request_token):
 
     def _on_access_token(self, callback, response):
         if response.error:
-            _log.warning("Could not fetch access token")
+            logging.warning("Could not fetch access token")
             callback(None)
             return
         access_token = _oauth_parse_response(response.body)
@@ -442,7 +440,7 @@ def _on_post(self, new_entry):
 
     def _on_twitter_request(self, callback, response):
         if response.error:
-            _log.warning("Error response %s fetching %s", response.error,
+            logging.warning("Error response %s fetching %s", response.error,
                             response.request.url)
             callback(None)
             return
@@ -562,7 +560,7 @@ def _on_post(self, new_entry):
 
     def _on_friendfeed_request(self, callback, response):
         if response.error:
-            _log.warning("Error response %s fetching %s", response.error,
+            logging.warning("Error response %s fetching %s", response.error,
                             response.request.url)
             callback(None)
             return
@@ -820,17 +818,17 @@ def _on_get_user_info(self, callback, session, users):
 
     def _parse_response(self, callback, response):
         if response.error:
-            _log.warning("HTTP error from Facebook: %s", response.error)
+            logging.warning("HTTP error from Facebook: %s", response.error)
             callback(None)
             return
         try:
             json = escape.json_decode(response.body)
         except:
-            _log.warning("Invalid JSON from Facebook: %r", response.body)
+            logging.warning("Invalid JSON from Facebook: %r", response.body)
             callback(None)
             return
         if isinstance(json, dict) and json.get("error_code"):
-            _log.warning("Facebook error: %d: %r", json["error_code"],
+            logging.warning("Facebook error: %d: %r", json["error_code"],
                             json.get("error_msg"))
             callback(None)
             return

tornado/autoreload.py

@@ -29,8 +29,6 @@
 import sys
 import types
 
-_log = logging.getLogger('tornado.autoreload')
-
 def start(io_loop=None, check_time=500):
     """Restarts the process automatically when a module is modified.
 
@@ -69,7 +67,7 @@ def _reload_on_update(io_loop, modify_times):
             modify_times[path] = modified
             continue
         if modify_times[path] != modified:
-            _log.info("%s modified; restarting server", path)
+            logging.info("%s modified; restarting server", path)
             _reload_attempted = True
             for fd in io_loop._handlers.keys():
                 try:

tornado/database.py

@@ -24,8 +24,6 @@
 import itertools
 import logging
 
-_log = logging.getLogger('tornado.database')
-
 class Connection(object):
     """A lightweight wrapper around MySQLdb DB-API connections.
 
@@ -72,7 +70,7 @@ def __init__(self, host, database, user=None, password=None):
         try:
             self.reconnect()
         except:
-            _log.error("Cannot connect to MySQL on %s", self.host,
+            logging.error("Cannot connect to MySQL on %s", self.host,
                           exc_info=True)
 
     def __del__(self):
@@ -151,7 +149,7 @@ def _execute(self, cursor, query, parameters):
         try:
             return cursor.execute(query, parameters)
         except OperationalError:
-            _log.error("Error connecting to MySQL on %s", self.host)
+            logging.error("Error connecting to MySQL on %s", self.host)
             self.close()
             raise
 

tornado/httpclient.py

@@ -29,8 +29,6 @@
 import time
 import weakref
 
-_log = logging.getLogger('tornado.httpclient')
-
 class HTTPClient(object):
     """A blocking HTTP client backed with pycurl.
 
@@ -348,7 +346,7 @@ def __init__(self, errno, message):
 
 def _curl_create(max_simultaneous_connections=None):
     curl = pycurl.Curl()
-    if _log.isEnabledFor(logging.DEBUG):
+    if logging.getLogger().isEnabledFor(logging.DEBUG):
         curl.setopt(pycurl.VERBOSE, 1)
         curl.setopt(pycurl.DEBUGFUNCTION, _curl_debug)
     curl.setopt(pycurl.MAXCONNECTS, max_simultaneous_connections or 5)
@@ -423,11 +421,11 @@ def ioctl(cmd):
         userpwd = "%s:%s" % (request.auth_username, request.auth_password)
         curl.setopt(pycurl.HTTPAUTH, pycurl.HTTPAUTH_BASIC)
         curl.setopt(pycurl.USERPWD, userpwd)
-        _log.info("%s %s (username: %r)", request.method, request.url,
+        logging.info("%s %s (username: %r)", request.method, request.url,
                      request.auth_username)
     else:
         curl.unsetopt(pycurl.USERPWD)
-        _log.info("%s %s", request.method, request.url)
+        logging.info("%s %s", request.method, request.url)
     if request.prepare_curl_callback is not None:
         request.prepare_curl_callback(curl)
 
@@ -440,7 +438,7 @@ def _curl_header_callback(headers, header_line):
         return
     parts = header_line.split(":", 1)
     if len(parts) != 2:
-        _log.warning("Invalid HTTP response header line %r", header_line)
+        logging.warning("Invalid HTTP response header line %r", header_line)
         return
     name = parts[0].strip()
     value = parts[1].strip()
@@ -453,12 +451,12 @@ def _curl_header_callback(headers, header_line):
 def _curl_debug(debug_type, debug_msg):
     debug_types = ('I', '<', '>', '<', '>')
     if debug_type == 0:
-        _log.debug('%s', debug_msg.strip())
+        logging.debug('%s', debug_msg.strip())
     elif debug_type in (1, 2):
         for line in debug_msg.splitlines():
-            _log.debug('%s %s', debug_types[debug_type], line)
+            logging.debug('%s %s', debug_types[debug_type], line)
     elif debug_type == 4:
-        _log.debug('%s %r', debug_types[debug_type], debug_msg)
+        logging.debug('%s %r', debug_types[debug_type], debug_msg)
 
 
 def _utf8(value):

tornado/httpserver.py

@@ -40,8 +40,6 @@
 except ImportError:
     ssl = None
 
-_log = logging.getLogger('tornado.httpserver')
-
 class HTTPServer(object):
     """A non-blocking, single-threaded HTTP server.
 
@@ -172,16 +170,16 @@ def start(self, num_processes=None):
             try:
                 num_processes = os.sysconf("SC_NPROCESSORS_CONF")
             except ValueError:
-                _log.error("Could not get num processors from sysconf; "
+                logging.error("Could not get num processors from sysconf; "
                               "running with one process")
                 num_processes = 1
         if num_processes > 1 and ioloop.IOLoop.initialized():
-            _log.error("Cannot run in multiple processes: IOLoop instance "
+            logging.error("Cannot run in multiple processes: IOLoop instance "
                           "has already been initialized. You cannot call "
                           "IOLoop.instance() before calling start()")
             num_processes = 1
         if num_processes > 1:
-            _log.info("Pre-forking %d server processes", num_processes)
+            logging.info("Pre-forking %d server processes", num_processes)
             for i in range(num_processes):
                 if os.fork() == 0:
                     self.io_loop = ioloop.IOLoop.instance()
@@ -218,7 +216,7 @@ def _handle_events(self, fd, events):
                 HTTPConnection(stream, address, self.request_callback,
                                self.no_keep_alive, self.xheaders)
             except:
-                _log.error("Error in connection callback", exc_info=True)
+                logging.error("Error in connection callback", exc_info=True)
 
 
 class HTTPConnection(object):
@@ -321,21 +319,21 @@ def _parse_mime_body(self, boundary, data):
             if not part: continue
             eoh = part.find("\r\n\r\n")
             if eoh == -1:
-                _log.warning("multipart/form-data missing headers")
+                logging.warning("multipart/form-data missing headers")
                 continue
             headers = HTTPHeaders.parse(part[:eoh])
             name_header = headers.get("Content-Disposition", "")
             if not name_header.startswith("form-data;") or \
                not part.endswith("\r\n"):
-                _log.warning("Invalid multipart/form-data")
+                logging.warning("Invalid multipart/form-data")
                 continue
             value = part[eoh + 4:-2]
             name_values = {}
             for name_part in name_header[10:].split(";"):
                 name, name_value = name_part.strip().split("=", 1)
                 name_values[name] = name_value.strip('"').decode("utf-8")
             if not name_values.get("name"):
-                _log.warning("multipart/form-data value missing name")
+                logging.warning("multipart/form-data value missing name")
                 continue
             name = name_values["name"]
             if name_values.get("filename"):

tornado/ioloop.py

@@ -32,8 +32,6 @@
     else:
         raise
 
-_log = logging.getLogger("tornado.ioloop")
-
 class IOLoop(object):
     """A level-triggered I/O loop.
 
@@ -154,7 +152,7 @@ def remove_handler(self, fd):
         try:
             self._impl.unregister(fd)
         except (OSError, IOError):
-            _log.debug("Error deleting fd from IOLoop", exc_info=True)
+            logging.debug("Error deleting fd from IOLoop", exc_info=True)
 
     def start(self):
         """Starts the I/O loop.
@@ -198,7 +196,7 @@ def start(self):
                 event_pairs = self._impl.poll(poll_timeout)
             except Exception, e:
                 if hasattr(e, 'errno') and e.errno == errno.EINTR:
-                    _log.warning("Interrupted system call", exc_info=1)
+                    logging.warning("Interrupted system call", exc_info=1)
                     continue
                 else:
                     raise
@@ -219,10 +217,10 @@ def start(self):
                         # Happens when the client closes the connection
                         pass
                     else:
-                        _log.error("Exception in I/O handler for fd %d",
+                        logging.error("Exception in I/O handler for fd %d",
                                       fd, exc_info=True)
                 except:
-                    _log.error("Exception in I/O handler for fd %d",
+                    logging.error("Exception in I/O handler for fd %d",
                                   fd, exc_info=True)
         # reset the stopped flag so another start/stop pair can be issued
         self._stopped = False
@@ -290,7 +288,7 @@ def handle_callback_exception(self, callback):
         The exception itself is not passed explicitly, but is available
         in sys.exc_info.
         """
-        _log.error("Exception in callback %r", callback, exc_info=True)
+        logging.error("Exception in callback %r", callback, exc_info=True)
 
     def _read_waker(self, fd, events):
         try:
@@ -348,7 +346,7 @@ def _run(self):
         except (KeyboardInterrupt, SystemExit):
             raise
         except:
-            _log.error("Error in periodic callback", exc_info=True)
+            logging.error("Error in periodic callback", exc_info=True)
         self.start()
 
 
@@ -479,5 +477,5 @@ def poll(self, timeout):
         # All other systems
         import sys
         if "linux" in sys.platform:
-            _log.warning("epoll module not found; using select()")
+            logging.warning("epoll module not found; using select()")
         _poll = _Select

tornado/iostream.py

@@ -21,8 +21,6 @@
 import logging
 import socket
 
-_log = logging.getLogger('tornado.iostream')
-
 class IOStream(object):
     """A utility class to write to and read from a non-blocking socket.
 
@@ -139,7 +137,7 @@ def closed(self):
 
     def _handle_events(self, fd, events):
         if not self.socket:
-            _log.warning("Got events for closed stream %d", fd)
+            logging.warning("Got events for closed stream %d", fd)
             return
         if events & self.io_loop.READ:
             self._handle_read()
@@ -168,7 +166,7 @@ def _handle_read(self):
             if e[0] in (errno.EWOULDBLOCK, errno.EAGAIN):
                 return
             else:
-                _log.warning("Read error on %d: %s",
+                logging.warning("Read error on %d: %s",
                                 self.socket.fileno(), e)
                 self.close()
                 return
@@ -177,7 +175,7 @@ def _handle_read(self):
             return
         self._read_buffer += chunk
         if len(self._read_buffer) >= self.max_buffer_size:
-            _log.error("Reached maximum read buffer size")
+            logging.error("Reached maximum read buffer size")
             self.close()
             return
         if self._read_bytes:
@@ -205,7 +203,7 @@ def _handle_write(self):
                 if e[0] in (errno.EWOULDBLOCK, errno.EAGAIN):
                     break
                 else:
-                    _log.warning("Write error on %d: %s",
+                    logging.warning("Write error on %d: %s",
                                     self.socket.fileno(), e)
                     self.close()
                     return

tornado/locale.py

@@ -51,8 +51,6 @@
 _supported_locales = frozenset([_default_locale])
 _use_gettext = False
 
-_log = logging.getLogger('tornado.locale')
-
 def get(*locale_codes):
     """Returns the closest match for the given locale codes.
 
@@ -112,7 +110,7 @@ def load_translations(directory):
         if not path.endswith(".csv"): continue
         locale, extension = path.split(".")
         if locale not in LOCALE_NAMES:
-            _log.error("Unrecognized locale %r (path: %s)", locale,
+            logging.error("Unrecognized locale %r (path: %s)", locale,
                           os.path.join(directory, path))
             continue
         f = open(os.path.join(directory, path), "r")
@@ -126,13 +124,13 @@ def load_translations(directory):
             else:
                 plural = "unknown"
             if plural not in ("plural", "singular", "unknown"):
-                _log.error("Unrecognized plural indicator %r in %s line %d",
+                logging.error("Unrecognized plural indicator %r in %s line %d",
                               plural, path, i + 1)
                 continue
             _translations[locale].setdefault(plural, {})[english] = translation
         f.close()
     _supported_locales = frozenset(_translations.keys() + [_default_locale])
-    _log.info("Supported locales: %s", sorted(_supported_locales))
+    logging.info("Supported locales: %s", sorted(_supported_locales))
 
 def load_gettext_translations(directory, domain):
     """Loads translations from gettext's locale tree
@@ -168,7 +166,7 @@ def load_gettext_translations(directory, domain):
             continue
     _supported_locales = frozenset(_translations.keys() + [_default_locale])
     _use_gettext = True
-    _log.info("Supported locales: %s", sorted(_supported_locales))
+    logging.info("Supported locales: %s", sorted(_supported_locales))
 
 
 def get_supported_locales(cls):