# Copyright 2019, OpenTelemetry Authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import atexit
import logging
import random
import threading
from contextlib import contextmanager
from numbers import Number
from types import TracebackType
from typing import Iterator, Optional, Sequence, Tuple, Type
from opentelemetry import context as context_api
from opentelemetry import trace as trace_api
from opentelemetry.sdk import util
from opentelemetry.sdk.util import BoundedDict, BoundedList
from opentelemetry.trace import SpanContext, sampling
from opentelemetry.trace.propagation import SPAN_KEY
from opentelemetry.trace.status import Status, StatusCanonicalCode
from opentelemetry.util import time_ns, types
logger = logging.getLogger(__name__)
MAX_NUM_ATTRIBUTES = 32
MAX_NUM_EVENTS = 128
MAX_NUM_LINKS = 32
[docs]class SpanProcessor:
"""Interface which allows hooks for SDK's `Span` start and end method
invocations.
Span processors can be registered directly using
:func:`TracerSource.add_span_processor` and they are invoked
in the same order as they were registered.
"""
[docs] def on_start(self, span: "Span") -> None:
"""Called when a :class:`opentelemetry.trace.Span` is started.
This method is called synchronously on the thread that starts the
span, therefore it should not block or throw an exception.
Args:
span: The :class:`opentelemetry.trace.Span` that just started.
"""
[docs] def on_end(self, span: "Span") -> None:
"""Called when a :class:`opentelemetry.trace.Span` is ended.
This method is called synchronously on the thread that ends the
span, therefore it should not block or throw an exception.
Args:
span: The :class:`opentelemetry.trace.Span` that just ended.
"""
[docs] def shutdown(self) -> None:
"""Called when a :class:`opentelemetry.sdk.trace.Tracer` is shutdown.
"""
[docs] def force_flush(self, timeout_millis: int = 30000) -> bool:
"""Export all ended spans to the configured Exporter that have not yet
been exported.
Args:
timeout_millis: The maximum amount of time to wait for spans to be
exported.
Returns:
False if the timeout is exceeded, True otherwise.
"""
[docs]class MultiSpanProcessor(SpanProcessor):
"""Implementation of :class:`SpanProcessor` that forwards all received
events to a list of `SpanProcessor`.
"""
def __init__(self):
# use a tuple to avoid race conditions when adding a new span and
# iterating through it on "on_start" and "on_end".
self._span_processors = () # type: Tuple[SpanProcessor, ...]
self._lock = threading.Lock()
[docs] def add_span_processor(self, span_processor: SpanProcessor) -> None:
"""Adds a SpanProcessor to the list handled by this instance."""
with self._lock:
self._span_processors = self._span_processors + (span_processor,)
[docs] def on_start(self, span: "Span") -> None:
for sp in self._span_processors:
sp.on_start(span)
[docs] def on_end(self, span: "Span") -> None:
for sp in self._span_processors:
sp.on_end(span)
[docs] def shutdown(self) -> None:
for sp in self._span_processors:
sp.shutdown()
[docs]class Span(trace_api.Span):
"""See `opentelemetry.trace.Span`.
Users should create `Span` objects via the `Tracer` instead of this
constructor.
Args:
name: The name of the operation this span represents
context: The immutable span context
parent: This span's parent, may be a `SpanContext` if the parent is
remote, null if this is a root span
sampler: The sampler used to create this span
trace_config: TODO
resource: TODO
attributes: The span's attributes to be exported
events: Timestamped events to be exported
links: Links to other spans to be exported
span_processor: `SpanProcessor` to invoke when starting and ending
this `Span`.
"""
# Initialize these lazily assuming most spans won't have them.
empty_attributes = BoundedDict(MAX_NUM_ATTRIBUTES)
empty_events = BoundedList(MAX_NUM_EVENTS)
empty_links = BoundedList(MAX_NUM_LINKS)
def __init__(
self,
name: str,
context: trace_api.SpanContext,
parent: trace_api.ParentSpan = None,
sampler: Optional[sampling.Sampler] = None,
trace_config: None = None, # TODO
resource: None = None, # TODO
attributes: types.Attributes = None, # TODO
events: Sequence[trace_api.Event] = None, # TODO
links: Sequence[trace_api.Link] = (),
kind: trace_api.SpanKind = trace_api.SpanKind.INTERNAL,
span_processor: SpanProcessor = SpanProcessor(),
instrumentation_info: "InstrumentationInfo" = None,
set_status_on_exception: bool = True,
) -> None:
self.name = name
self.context = context
self.parent = parent
self.sampler = sampler
self.trace_config = trace_config
self.resource = resource
self.kind = kind
self._set_status_on_exception = set_status_on_exception
self.span_processor = span_processor
self.status = None
self._lock = threading.Lock()
if attributes is None:
self.attributes = Span.empty_attributes
else:
self.attributes = BoundedDict.from_map(
MAX_NUM_ATTRIBUTES, attributes
)
if events is None:
self.events = Span.empty_events
else:
self.events = BoundedList.from_seq(MAX_NUM_EVENTS, events)
if links is None:
self.links = Span.empty_links
else:
self.links = BoundedList.from_seq(MAX_NUM_LINKS, links)
self._end_time = None # type: Optional[int]
self._start_time = None # type: Optional[int]
self.instrumentation_info = instrumentation_info
@property
def start_time(self):
return self._start_time
@property
def end_time(self):
return self._end_time
def __repr__(self):
return '{}(name="{}", context={})'.format(
type(self).__name__, self.name, self.context
)
def __str__(self):
return (
'{}(name="{}", context={}, kind={}, '
"parent={}, start_time={}, end_time={})"
).format(
type(self).__name__,
self.name,
self.context,
self.kind,
repr(self.parent),
util.ns_to_iso_str(self.start_time) if self.start_time else "None",
util.ns_to_iso_str(self.end_time) if self.end_time else "None",
)
[docs] def get_context(self):
return self.context
[docs] def set_attribute(self, key: str, value: types.AttributeValue) -> None:
with self._lock:
if not self.is_recording_events():
return
has_ended = self.end_time is not None
if not has_ended:
if self.attributes is Span.empty_attributes:
self.attributes = BoundedDict(MAX_NUM_ATTRIBUTES)
if has_ended:
logger.warning("Setting attribute on ended span.")
return
if isinstance(value, Sequence):
error_message = self._check_attribute_value_sequence(value)
if error_message is not None:
logger.warning("%s in attribute value sequence", error_message)
return
elif not isinstance(value, (bool, str, Number, Sequence)):
logger.warning("invalid type for attribute value")
return
self.attributes[key] = value
@staticmethod
def _check_attribute_value_sequence(sequence: Sequence) -> Optional[str]:
"""
Checks if sequence items are valid and are of the same type
"""
if len(sequence) == 0:
return None
first_element_type = type(sequence[0])
if issubclass(first_element_type, Number):
first_element_type = Number
if first_element_type not in (bool, str, Number):
return "invalid type"
for element in sequence:
if not isinstance(element, first_element_type):
return "different type"
return None
[docs] def add_event(
self,
name: str,
attributes: types.Attributes = None,
timestamp: Optional[int] = None,
) -> None:
self.add_lazy_event(
trace_api.Event(
name,
Span.empty_attributes if attributes is None else attributes,
time_ns() if timestamp is None else timestamp,
)
)
[docs] def add_lazy_event(self, event: trace_api.Event) -> None:
with self._lock:
if not self.is_recording_events():
return
has_ended = self.end_time is not None
if not has_ended:
if self.events is Span.empty_events:
self.events = BoundedList(MAX_NUM_EVENTS)
if has_ended:
logger.warning("Calling add_event() on an ended span.")
return
self.events.append(event)
[docs] def start(self, start_time: Optional[int] = None) -> None:
with self._lock:
if not self.is_recording_events():
return
has_started = self.start_time is not None
if not has_started:
self._start_time = (
start_time if start_time is not None else time_ns()
)
if has_started:
logger.warning("Calling start() on a started span.")
return
self.span_processor.on_start(self)
[docs] def end(self, end_time: Optional[int] = None) -> None:
with self._lock:
if not self.is_recording_events():
return
if self.start_time is None:
raise RuntimeError("Calling end() on a not started span.")
has_ended = self.end_time is not None
if not has_ended:
if self.status is None:
self.status = Status(canonical_code=StatusCanonicalCode.OK)
self._end_time = (
end_time if end_time is not None else time_ns()
)
if has_ended:
logger.warning("Calling end() on an ended span.")
return
self.span_processor.on_end(self)
[docs] def update_name(self, name: str) -> None:
with self._lock:
has_ended = self.end_time is not None
if has_ended:
logger.warning("Calling update_name() on an ended span.")
return
self.name = name
[docs] def is_recording_events(self) -> bool:
return True
[docs] def set_status(self, status: trace_api.Status) -> None:
with self._lock:
has_ended = self.end_time is not None
if has_ended:
logger.warning("Calling set_status() on an ended span.")
return
self.status = status
def __exit__(
self,
exc_type: Optional[Type[BaseException]],
exc_val: Optional[BaseException],
exc_tb: Optional[TracebackType],
) -> None:
"""Ends context manager and calls `end` on the `Span`."""
if (
self.status is None
and self._set_status_on_exception
and exc_val is not None
):
self.set_status(
Status(
canonical_code=StatusCanonicalCode.UNKNOWN,
description="{}: {}".format(exc_type.__name__, exc_val),
)
)
super().__exit__(exc_type, exc_val, exc_tb)
[docs]def generate_span_id() -> int:
"""Get a new random span ID.
Returns:
A random 64-bit int for use as a span ID
"""
return random.getrandbits(64)
[docs]def generate_trace_id() -> int:
"""Get a new random trace ID.
Returns:
A random 128-bit int for use as a trace ID
"""
return random.getrandbits(128)
[docs]class InstrumentationInfo:
"""Immutable information about an instrumentation library module.
See `TracerSource.get_tracer` for the meaning of the properties.
"""
__slots__ = ("_name", "_version")
def __init__(self, name: str, version: str):
self._name = name
self._version = version
def __repr__(self):
return "{}({}, {})".format(
type(self).__name__, self._name, self._version
)
def __hash__(self):
return hash((self._name, self._version))
def __eq__(self, value):
return type(value) is type(self) and (self._name, self._version) == (
value._name,
value._version,
)
def __lt__(self, value):
if type(value) is not type(self):
return NotImplemented
return (self._name, self._version) < (value._name, value._version)
@property
def version(self) -> str:
return self._version
@property
def name(self) -> str:
return self._name
[docs]class Tracer(trace_api.Tracer):
"""See `opentelemetry.trace.Tracer`.
Args:
name: The name of the tracer.
shutdown_on_exit: Register an atexit hook to shut down the tracer when
the application exits.
"""
def __init__(
self, source: "TracerSource", instrumentation_info: InstrumentationInfo
) -> None:
self.source = source
self.instrumentation_info = instrumentation_info
[docs] def get_current_span(self):
"""See `opentelemetry.trace.Tracer.get_current_span`."""
return self.source.get_current_span()
[docs] def start_as_current_span(
self,
name: str,
parent: trace_api.ParentSpan = trace_api.Tracer.CURRENT_SPAN,
kind: trace_api.SpanKind = trace_api.SpanKind.INTERNAL,
attributes: Optional[types.Attributes] = None,
links: Sequence[trace_api.Link] = (),
) -> Iterator[trace_api.Span]:
"""See `opentelemetry.trace.Tracer.start_as_current_span`."""
span = self.start_span(name, parent, kind, attributes, links)
return self.use_span(span, end_on_exit=True)
[docs] def start_span( # pylint: disable=too-many-locals
self,
name: str,
parent: trace_api.ParentSpan = trace_api.Tracer.CURRENT_SPAN,
kind: trace_api.SpanKind = trace_api.SpanKind.INTERNAL,
attributes: Optional[types.Attributes] = None,
links: Sequence[trace_api.Link] = (),
start_time: Optional[int] = None,
set_status_on_exception: bool = True,
) -> trace_api.Span:
"""See `opentelemetry.trace.Tracer.start_span`."""
if parent is Tracer.CURRENT_SPAN:
parent = self.get_current_span()
parent_context = parent
if isinstance(parent_context, trace_api.Span):
parent_context = parent.get_context()
if parent_context is not None and not isinstance(
parent_context, trace_api.SpanContext
):
raise TypeError
if parent_context is None or not parent_context.is_valid():
parent = parent_context = None
trace_id = generate_trace_id()
trace_options = None
trace_state = None
else:
trace_id = parent_context.trace_id
trace_options = parent_context.trace_options
trace_state = parent_context.trace_state
context = trace_api.SpanContext(
trace_id, generate_span_id(), trace_options, trace_state
)
# The sampler decides whether to create a real or no-op span at the
# time of span creation. No-op spans do not record events, and are not
# exported.
# The sampler may also add attributes to the newly-created span, e.g.
# to include information about the sampling decision.
sampling_decision = self.source.sampler.should_sample(
parent_context,
context.trace_id,
context.span_id,
name,
attributes,
links,
)
if sampling_decision.sampled:
options = context.trace_options | trace_api.TraceOptions.SAMPLED
context.trace_options = trace_api.TraceOptions(options)
if attributes is None:
span_attributes = sampling_decision.attributes
else:
# apply sampling decision attributes after initial attributes
span_attributes = attributes.copy()
span_attributes.update(sampling_decision.attributes)
span = Span(
name=name,
context=context,
parent=parent,
sampler=self.source.sampler,
attributes=span_attributes,
span_processor=self.source._active_span_processor, # pylint:disable=protected-access
kind=kind,
links=links,
instrumentation_info=self.instrumentation_info,
set_status_on_exception=set_status_on_exception,
)
span.start(start_time=start_time)
else:
span = trace_api.DefaultSpan(context=context)
return span
[docs] @contextmanager
def use_span(
self, span: trace_api.Span, end_on_exit: bool = False
) -> Iterator[trace_api.Span]:
"""See `opentelemetry.trace.Tracer.use_span`."""
try:
context_snapshot = context_api.get_current()
context_api.set_current(context_api.set_value(SPAN_KEY, span))
try:
yield span
finally:
context_api.set_current(context_snapshot)
except Exception as error: # pylint: disable=broad-except
if (
span.status is None
and span._set_status_on_exception # pylint:disable=protected-access # noqa
):
span.set_status(
Status(
canonical_code=StatusCanonicalCode.UNKNOWN,
description="{}: {}".format(
type(error).__name__, error
),
)
)
raise
finally:
if end_on_exit:
span.end()
[docs]class TracerSource(trace_api.TracerSource):
def __init__(
self,
sampler: sampling.Sampler = trace_api.sampling.ALWAYS_ON,
shutdown_on_exit: bool = True,
):
self._active_span_processor = MultiSpanProcessor()
self.sampler = sampler
self._atexit_handler = None
if shutdown_on_exit:
self._atexit_handler = atexit.register(self.shutdown)
[docs] def get_tracer(
self,
instrumenting_module_name: str,
instrumenting_library_version: str = "",
) -> "trace_api.Tracer":
if not instrumenting_module_name: # Reject empty strings too.
instrumenting_module_name = "ERROR:MISSING MODULE NAME"
logger.error("get_tracer called with missing module name.")
return Tracer(
self,
InstrumentationInfo(
instrumenting_module_name, instrumenting_library_version
),
)
[docs] @staticmethod
def get_current_span() -> Span:
return context_api.get_value(SPAN_KEY) # type: ignore
[docs] def add_span_processor(self, span_processor: SpanProcessor) -> None:
"""Registers a new :class:`SpanProcessor` for this `TracerSource`.
The span processors are invoked in the same order they are registered.
"""
# no lock here because MultiSpanProcessor.add_span_processor is
# thread safe
self._active_span_processor.add_span_processor(span_processor)
[docs] def shutdown(self):
"""Shut down the span processors added to the tracer."""
self._active_span_processor.shutdown()
if self._atexit_handler is not None:
atexit.unregister(self._atexit_handler)
self._atexit_handler = None