further optimize conf.settings access when logging is enabled

the callback receiver is still fairly slow when logging is enabled due
to constant setting lookups; this speeds things up considerably

related: ansible#5618

awx/conf/settings.py

@@ -1,5 +1,4 @@
 # Python
-from collections import namedtuple
 import contextlib
 import logging
 import re
@@ -136,6 +135,15 @@ def filter_sensitive(registry, key, value):
     return value
 
 
+class TransientSetting(object):
+
+    __slots__ = ('pk', 'value')
+
+    def __init__(self, pk, value):
+        self.pk = pk
+        self.value = value
+
+
 class EncryptedCacheProxy(object):
 
     def __init__(self, cache, registry, encrypter=None, decrypter=None):
@@ -186,8 +194,6 @@ def set_many(self, data, **kwargs):
             self.set(key, value, log=False, **kwargs)
 
     def _handle_encryption(self, method, key, value):
-        TransientSetting = namedtuple('TransientSetting', ['pk', 'value'])
-
         if value is not empty and self.registry.is_setting_encrypted(key):
             # If the setting exists in the database, we'll use its primary key
             # as part of the AES key when encrypting/decrypting

awx/main/utils/formatters.py

@@ -107,6 +107,17 @@ def serialize(cls, message):
 
 class LogstashFormatter(LogstashFormatterBase):
 
+    def __init__(self, *args, **kwargs):
+        self.cluster_host_id = settings.CLUSTER_HOST_ID
+        self.tower_uuid = None
+        uuid = (
+            getattr(settings, 'LOG_AGGREGATOR_TOWER_UUID', None) or
+            getattr(settings, 'INSTALL_UUID', None)
+        )
+        if uuid:
+            self.tower_uuid = uuid
+        super(LogstashFormatter, self).__init__(*args, **kwargs)
+
     def reformat_data_for_log(self, raw_data, kind=None):
         '''
         Process dictionaries from various contexts (job events, activity stream
@@ -231,21 +242,8 @@ def get_extra_fields(self, record):
             log_kind = record.name[len('awx.analytics.'):]
             fields = self.reformat_data_for_log(fields, kind=log_kind)
         # General AWX metadata
-        for log_name, setting_name in [
-                ('type', 'LOG_AGGREGATOR_TYPE'),
-                ('cluster_host_id', 'CLUSTER_HOST_ID'),
-                ('tower_uuid', 'LOG_AGGREGATOR_TOWER_UUID')]:
-            if hasattr(settings, setting_name):
-                fields[log_name] = getattr(settings, setting_name, None)
-            elif log_name == 'type':
-                fields[log_name] = 'other'
-
-        uuid = (
-            getattr(settings, 'LOG_AGGREGATOR_TOWER_UUID', None) or
-            getattr(settings, 'INSTALL_UUID', None)
-        )
-        if uuid:
-            fields['tower_uuid'] = uuid
+        fields['cluster_host_id'] = self.cluster_host_id
+        fields['tower_uuid'] = self.tower_uuid
         return fields
 
     def format(self, record):

awx/main/utils/handlers.py

@@ -4,6 +4,7 @@
 # Python
 import logging
 import json
+import os
 import requests
 import time
 import threading
@@ -18,6 +19,7 @@
 
 # requests futures, a dependency used by these handlers
 from requests_futures.sessions import FuturesSession
+import cachetools
 
 # AWX
 from awx.main.utils.formatters import LogstashFormatter
@@ -273,6 +275,16 @@ def __init__(self, *args, **kwargs):
 }
 
 
+TTLCache = cachetools.TTLCache
+
+if 'py.test' in os.environ.get('_', ''):
+    # don't cache settings in unit tests
+    class TTLCache(TTLCache):
+
+        def __getitem__(self, item):
+            raise KeyError()
+
+
 class AWXProxyHandler(logging.Handler):
     '''
     Handler specific to the AWX external logging feature
@@ -316,6 +328,7 @@ def serialize(cls, message):
     def get_handler_class(self, protocol):
         return HANDLER_MAPPING.get(protocol, AWXNullHandler)
 
+    @cachetools.cached(cache=TTLCache(maxsize=1, ttl=3), key=lambda *args, **kw: 'get_handler')
     def get_handler(self, custom_settings=None, force_create=False):
         new_kwargs = {}
         use_settings = custom_settings or settings
@@ -342,10 +355,14 @@ def get_handler(self, custom_settings=None, force_create=False):
             self._handler.setFormatter(self.formatter)
         return self._handler
 
+    @cachetools.cached(cache=TTLCache(maxsize=1, ttl=3), key=lambda *args, **kw: 'should_audit')
+    def should_audit(self):
+        return settings.LOG_AGGREGATOR_AUDIT
+
     def emit(self, record):
         if AWXProxyHandler.thread_local.enabled:
             actual_handler = self.get_handler()
-            if settings.LOG_AGGREGATOR_AUDIT:
+            if self.should_audit():
                 self.auditor.setLevel(settings.LOG_AGGREGATOR_LEVEL)
                 self.auditor.emit(record)
             return actual_handler.emit(record)