NoopSpan on queue full, propagation downstream (#141)

skywalking/agent/__init__.py

@@ -168,6 +168,10 @@ def started():
     return __started
 
 
+def isfull():
+    return __queue.full()
+
+
 def archive(segment: 'Segment'):
     try:  # unlike checking __queue.full() then inserting, this is atomic
         __queue.put(segment, block=False)

skywalking/plugins/sw_urllib_request.py

@@ -41,7 +41,8 @@ def _sw_open(this: OpenerDirector, fullurl, data=None, timeout=socket._GLOBAL_DE
             span.layer = Layer.Http
             code = None
 
-            [fullurl.add_header(item.key, item.val) for item in carrier]
+            for item in carrier:
+                fullurl.add_header(item.key, item.val)
 
             try:
                 res = _open(this, fullurl, data, timeout)

skywalking/trace/carrier.py

@@ -48,6 +48,7 @@ def __init__(self, trace_id: str = '', segment_id: str = '', span_id: str = '',
                  service_instance: str = '', endpoint: str = '', client_address: str = '',
                  correlation: dict = None):  # pyre-ignore
         super(Carrier, self).__init__(key='sw8')
+        self.__val = None
         self.trace_id = trace_id  # type: str
         self.segment_id = segment_id  # type: str
         self.span_id = span_id  # type: str
@@ -101,6 +102,10 @@ def is_valid(self):
                len(self.client_address) > 0 and \
                self.span_id.isnumeric()
 
+    @property
+    def is_suppressed(self):  # if is invalid from previous set, ignored or suppressed status propagation downstream
+        return self.__val and not self.is_valid
+
     def __iter__(self):
         self.__iter_index = 0
         return self

skywalking/trace/context.py

@@ -16,6 +16,7 @@
 #
 
 from skywalking import Component, agent, config
+from skywalking.agent import isfull
 from skywalking.trace import ID
 from skywalking.trace.carrier import Carrier
 from skywalking.trace.segment import Segment, SegmentRef
@@ -75,12 +76,18 @@ def __init__(self):
         self._correlation = {}  # type: dict
         self._nspans = 0
 
+    def ignore_check(self, op: str, kind: Kind, carrier: 'Carrier' = None):
+        if config.RE_IGNORE_PATH.match(op) or isfull() or (carrier is not None and carrier.is_suppressed):
+            return NoopSpan(context=NoopContext())
+
+        return None
+
     def new_local_span(self, op: str) -> Span:
         span = self.ignore_check(op, Kind.Local)
         if span is not None:
             return span
 
-        spans = _spans_dup()
+        spans = _spans()
         parent = spans[-1] if spans else None  # type: Span
 
         return Span(
@@ -92,11 +99,11 @@ def new_local_span(self, op: str) -> Span:
         )
 
     def new_entry_span(self, op: str, carrier: 'Carrier' = None, inherit: Component = None) -> Span:
-        span = self.ignore_check(op, Kind.Entry)
+        span = self.ignore_check(op, Kind.Entry, carrier)
         if span is not None:
             return span
 
-        spans = _spans_dup()
+        spans = _spans()
         parent = spans[-1] if spans else None  # type: Span
 
         if parent is not None and parent.kind.is_entry and inherit == parent.component:
@@ -120,12 +127,13 @@ def new_exit_span(self, op: str, peer: str, component: Component = None, inherit
         if span is not None:
             return span
 
-        spans = _spans_dup()
+        spans = _spans()
         parent = spans[-1] if spans else None  # type: Span
 
         if parent is not None and parent.kind.is_exit and component == parent.inherit:
             span = parent
             span.op = op
+            span.peer = peer
             span.component = component
         else:
             span = ExitSpan(
@@ -142,23 +150,14 @@ def new_exit_span(self, op: str, peer: str, component: Component = None, inherit
 
         return span
 
-    def ignore_check(self, op: str, kind: Kind):
-        if config.RE_IGNORE_PATH.match(op):
-            return NoopSpan(
-                context=NoopContext(),
-                kind=kind,
-            )
-
-        return None
-
     def start(self, span: Span):
         self._nspans += 1
-        spans = _spans()
+        spans = _spans_dup()
         if span not in spans:
             spans.append(span)
 
     def stop(self, span: Span) -> bool:
-        spans = _spans()
+        spans = _spans_dup()
         span.finish(self.segment)
 
         try:
@@ -225,30 +224,27 @@ def continued(self, snapshot: 'Snapshot'):
 class NoopContext(SpanContext):
     def __init__(self):
         super().__init__()
-        self._depth = 0
-        self._noop_span = NoopSpan(self, kind=Kind.Local)
-        self.correlation = {}  # type: dict
 
     def new_local_span(self, op: str) -> Span:
-        return self._noop_span
+        return NoopSpan(self)
 
     def new_entry_span(self, op: str, carrier: 'Carrier' = None, inherit: Component = None) -> Span:
-        if carrier is not None:
-            self._noop_span.extract(carrier)
-        return self._noop_span
+        return NoopSpan(self)
 
     def new_exit_span(self, op: str, peer: str, component: Component = None, inherit: Component = None) -> Span:
-        return self._noop_span
-
-    def start(self, span: Span):
-        self._depth += 1
+        return NoopSpan(self)
 
     def stop(self, span: Span) -> bool:
-        self._depth -= 1
-        return self._depth == 0
+        spans = _spans_dup()
 
-    def active_span(self):
-        return self._noop_span
+        try:
+            spans.remove(span)
+        except Exception:
+            pass
+
+        self._nspans -= 1
+
+        return self._nspans == 0
 
     def capture(self):
         return Snapshot(

skywalking/trace/span.py

@@ -220,12 +220,11 @@ def inject(self) -> 'Carrier':
 
 @tostring
 class NoopSpan(Span):
-    def __init__(self, context: 'SpanContext' = None, kind: 'Kind' = None):
-        Span.__init__(self, context=context, kind=kind)
+    def __init__(self, context: 'SpanContext' = None):
+        Span.__init__(self, context=context, op='', kind=Kind.Local)
 
     def extract(self, carrier: 'Carrier'):
-        if carrier is not None:
-            self.context._correlation = carrier.correlation_carrier.correlation
+        return
 
     def inject(self) -> 'Carrier':
-        return Carrier(correlation=self.context._correlation)
+        return Carrier()