release commit for 0.96

CHANGELOG.rst

@@ -2,13 +2,15 @@
 CHANGELOG
 =========
 
-Unreleased
-==========
+0.96
+====
 * feature: Add support for SQLAlchemy and Flask-SQLAlcemy. `PR14 <https://github.com/aws/aws-xray-sdk-python/pull/14>`_.
 * feature: Add support for PynamoDB calls to DynamoDB. `PR13 <https://github.com/aws/aws-xray-sdk-python/pull/13>`_.
-* feature: Add support for httplib calls `PR19 <https://github.com/aws/aws-xray-sdk-python/pull/19>`_.
+* feature: Add support for httplib calls. `PR19 <https://github.com/aws/aws-xray-sdk-python/pull/19>`_.
+* feature: Make streaming threshold configurable through public interface. `ISSUE21 <https://github.com/aws/aws-xray-sdk-python/issues/21>`_.
 * bugfix:  Drop invalid annotation keys and log a warning. `PR22 <https://github.com/aws/aws-xray-sdk-python/pull/22>`_.
 * bugfix:  Respect `with` statement on cursor objects in dbapi2 patcher. `PR17 <https://github.com/aws/aws-xray-sdk-python/pull/17>`_.
+* bugfix:  Don't throw error from built in subsegment capture when `LOG_ERROR` is set. `ISSUE4 <https://github.com/aws/aws-xray-sdk-python/issues/4>`_.
 
 0.95
 ====

aws_xray_sdk/core/recorder.py

@@ -57,7 +57,7 @@ def configure(self, sampling=None, plugins=None,
                   context_missing=None, sampling_rules=None,
                   daemon_address=None, service=None,
                   context=None, emitter=None,
-                  dynamic_naming=None):
+                  dynamic_naming=None, streaming_threshold=None):
         """Configure global X-Ray recorder.
 
         Configure needs to run before patching thrid party libraries
@@ -90,6 +90,9 @@ def configure(self, sampling=None, plugins=None,
         :param dynamic_naming: a string that defines a pattern that host names
             should match. Alternatively you can pass a module which
             overrides ``DefaultDynamicNaming`` module.
+        :param streaming_threshold: If breaks within a single segment it will
+            start streaming out children subsegments. By default it is the
+            maximum number of subsegments within a segment.
 
         Environment variables AWS_XRAY_DAEMON_ADDRESS, AWS_XRAY_CONTEXT_MISSING
         and AWS_XRAY_TRACING_NAME respectively overrides arguments
@@ -111,6 +114,8 @@ def configure(self, sampling=None, plugins=None,
             self.context.context_missing = os.getenv(CONTEXT_MISSING_KEY, context_missing)
         if dynamic_naming:
             self.dynamic_naming = dynamic_naming
+        if streaming_threshold:
+            self.streaming_threshold = streaming_threshold
 
         plugin_modules = None
         if plugins:
@@ -259,7 +264,7 @@ def stream_subsegments(self):
         if not segment or not segment.sampled:
             return
 
-        if segment.get_total_subsegments_size() <= self._max_subsegments:
+        if segment.get_total_subsegments_size() <= self.streaming_threshold:
             return
 
         # find all subsegments that has no open child subsegments and
@@ -326,6 +331,10 @@ def record_subsegment(self, wrapped, instance, args, kwargs, name,
             stack = traceback.extract_stack(limit=self._max_trace_back)
             raise
         finally:
+            # No-op if subsegment is `None` due to `LOG_ERROR`.
+            if subsegment is None:
+                return
+
             end_time = time.time()
             if callable(meta_processor):
                 meta_processor(
@@ -440,3 +449,11 @@ def emitter(self):
     @emitter.setter
     def emitter(self, value):
         self._emitter = value
+
+    @property
+    def streaming_threshold(self):
+        return self._max_subsegments
+
+    @streaming_threshold.setter
+    def streaming_threshold(self, value):
+        self._max_subsegments = value

aws_xray_sdk/ext/django/apps.py

@@ -34,6 +34,7 @@ def ready(self):
             plugins=settings.PLUGINS,
             service=settings.AWS_XRAY_TRACING_NAME,
             dynamic_naming=settings.DYNAMIC_NAMING,
+            streaming_threshold=settings.STREAMING_THRESHOLD,
         )
 
         # if turned on subsegment will be generated on

aws_xray_sdk/ext/django/conf.py

@@ -12,6 +12,7 @@
     'SAMPLING_RULES': None,
     'AWS_XRAY_TRACING_NAME': None,
     'DYNAMIC_NAMING': None,
+    'STREAMING_THRESHOLD': None,
 }
 
 XRAY_NAMESPACE = 'XRAY_RECORDER'

aws_xray_sdk/ext/httplib/patch.py

@@ -20,6 +20,8 @@
 
 _XRAY_PROP = '_xray_prop'
 _XRay_Data = namedtuple('xray_data', ['method', 'host', 'url'])
+# A flag indicates whether this module is X-Ray patched or not
+PATCH_FLAG = '__xray_patched'
 
 
 def http_response_processor(wrapped, instance, args, kwargs, return_value,
@@ -113,11 +115,10 @@ def _xray_traced_http_client_read(wrapped, instance, args, kwargs):
 
 def patch():
     """ patch the built-in urllib/httplib/httplib.client methods for tracing"""
-
-    # we set an attribute to avoid double unwrapping
-    if getattr(httplib, '__xray_patch', False):
+    if getattr(httplib, PATCH_FLAG, False):
         return
-    setattr(httplib, '__xray_patch', True)
+    # we set an attribute to avoid multiple wrapping
+    setattr(httplib, PATCH_FLAG, True)
 
     wrapt.wrap_function_wrapper(
         httplib_client_module,
@@ -139,13 +140,12 @@ def patch():
 
 
 def unpatch():
-    """ unpatch any previously patched modules """
-    if not getattr(httplib, '__xray_patch', False):
-        return
-    setattr(httplib, '__xray_patch', False)
-
-    # send_request encapsulates putrequest, putheader[s], and endheaders
-    # NOTE that requests
+    """
+    Unpatch any previously patched modules.
+    This operation is idempotent.
+    """
+    setattr(httplib, PATCH_FLAG, False)
+    # _send_request encapsulates putrequest, putheader[s], and endheaders
     unwrap(httplib.HTTPConnection, '_send_request')
     unwrap(httplib.HTTPConnection, 'getresponse')
-    unwrap(httplib.HTTPConnection, 'read')
+    unwrap(httplib.HTTPResponse, 'read')

docs/frameworks.rst

@@ -45,6 +45,7 @@ The default values are as follows::
         'SAMPLING_RULES': None,
         'AWS_XRAY_TRACING_NAME': None, # the segment name for segments generated from incoming requests
         'DYNAMIC_NAMING': None, # defines a pattern that host names should match
+        'STREAMING_THRESHOLD': None, # defines when a segment starts to stream out its children subsegments
     }
 
 Environment variables have higher precedence over user settings.

setup.py

@@ -9,7 +9,7 @@
 
 setup(
     name='aws-xray-sdk',
-    version='0.95',
+    version='0.96',
 
     description='The AWS X-Ray SDK for Python (the SDK) enables Python developers to record'
                 ' and emit information from within their applications to the AWS X-Ray service.',

tests/ext/botocore/test_botocore.py

@@ -103,3 +103,25 @@ def test_map_parameter_grouping():
 
     aws_meta = subsegment.aws
     assert sorted(aws_meta['table_names']) == ['table1', 'table2']
+
+def test_pass_through_on_context_missing():
+    """
+    The built-in patcher or subsegment capture logic should not throw
+    any error when a `None` subsegment created from `LOG_ERROR` missing context.
+    """
+    xray_recorder.configure(context_missing='LOG_ERROR')
+    xray_recorder.clear_trace_entities()
+
+    ddb = session.create_client('dynamodb', region_name='us-west-2')
+    response = {
+        'ResponseMetadata': {
+            'RequestId': REQUEST_ID,
+            'HTTPStatusCode': 200,
+        }
+    }
+
+    with Stubber(ddb) as stubber:
+        stubber.add_response('describe_table', response, {'TableName': 'mytable'})
+        ddb.describe_table(TableName='mytable')
+
+    xray_recorder.configure(context_missing='RUNTIME_ERROR')

tests/test_recorder.py

@@ -30,12 +30,13 @@ def test_subsegment_parenting():
 
 
 def test_subsegments_streaming():
-
+    xray_recorder.configure(streaming_threshold=10)
     segment = xray_recorder.begin_segment('name')
-    for i in range(0, 50):
+    for i in range(0, 11):
         xray_recorder.begin_subsegment(name=str(i))
-    for i in range(0, 40):
+    for i in range(0, 1):
+        # subsegment '10' will be streamed out upon close
         xray_recorder.end_subsegment()
 
-    assert segment.get_total_subsegments_size() < 50
+    assert segment.get_total_subsegments_size() == 10
     assert xray_recorder.current_subsegment().name == '9'