Add StartupTimingObserver for measuring processor start() times

Tracks how long each processor start method takes during pipeline
startup by measuring StartFrame arrive/leave deltas. Emits a timing
report via the on_startup_timing_report event and auto-logs a summary.
Internal pipeline processors are excluded from reports by default.
This commit is contained in:
Mark Backman
2026-02-28 14:04:21 -05:00
parent 5a6a93e277
commit c54232bdb4
3 changed files with 427 additions and 3 deletions

View File

@@ -12,6 +12,7 @@ from loguru import logger
from pipecat.audio.vad.silero import SileroVADAnalyzer
from pipecat.frames.frames import LLMRunFrame
from pipecat.observers.startup_timing_observer import StartupTimingObserver
from pipecat.observers.user_bot_latency_observer import UserBotLatencyObserver
from pipecat.pipeline.pipeline import Pipeline
from pipecat.pipeline.runner import PipelineRunner
@@ -87,8 +88,8 @@ async def run_bot(transport: BaseTransport, runner_args: RunnerArguments):
]
)
# Create latency tracking observer
latency_observer = UserBotLatencyObserver()
startup_observer = StartupTimingObserver()
task = PipelineTask(
pipeline,
@@ -97,14 +98,19 @@ async def run_bot(transport: BaseTransport, runner_args: RunnerArguments):
enable_usage_metrics=True,
),
idle_timeout_secs=runner_args.pipeline_idle_timeout_secs,
observers=[latency_observer],
observers=[latency_observer, startup_observer],
)
# Log latency measurements using the event handler
@latency_observer.event_handler("on_latency_measured")
async def on_latency_measured(observer, latency_seconds):
logger.info(f"⏱️ User-to-bot latency: {latency_seconds:.3f}s")
@startup_observer.event_handler("on_startup_timing_report")
async def on_startup_timing_report(observer, report):
logger.info(f"Total startup: {report.total_duration_secs:.3f}s")
for timing in report.processor_timings:
logger.info(f" {timing.processor_name}: {timing.duration_secs:.3f}s")
turn_observer = task.turn_tracking_observer
if turn_observer:

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@@ -0,0 +1,232 @@
#
# Copyright (c) 2024-2026, Daily
#
# SPDX-License-Identifier: BSD 2-Clause License
#
"""Observer for tracking pipeline startup timing.
This module provides an observer that measures how long each processor's
``start()`` method takes during pipeline startup. It works by tracking
when a ``StartFrame`` arrives at a processor (``on_process_frame``) versus
when it leaves (``on_push_frame``), giving the exact ``start()`` duration
for each processor in the pipeline.
Example::
observer = StartupTimingObserver()
@observer.event_handler("on_startup_timing_report")
async def on_report(observer, report):
for t in report.processor_timings:
print(f"{t.processor_name}: {t.duration_secs:.3f}s")
task = PipelineTask(pipeline, observers=[observer])
"""
from dataclasses import dataclass, field
from typing import Dict, List, Optional, Tuple, Type
from loguru import logger
from pipecat.frames.frames import StartFrame
from pipecat.observers.base_observer import BaseObserver, FrameProcessed, FramePushed
from pipecat.pipeline.base_pipeline import BasePipeline
from pipecat.pipeline.pipeline import PipelineSink, PipelineSource
from pipecat.processors.frame_processor import FrameDirection, FrameProcessor
# Internal pipeline types excluded from tracking by default.
_INTERNAL_TYPES = (PipelineSink, PipelineSource, BasePipeline)
@dataclass
class ProcessorStartupTiming:
"""Startup timing for a single processor.
Parameters:
processor_name: The name of the processor.
duration_secs: How long the processor's start() took, in seconds.
"""
processor_name: str
duration_secs: float
@dataclass
class StartupTimingReport:
"""Report of startup timings for all measured processors.
Parameters:
total_duration_secs: Total wall-clock time from first to last processor start.
processor_timings: Per-processor timing data, in pipeline order.
"""
total_duration_secs: float
processor_timings: List[ProcessorStartupTiming] = field(default_factory=list)
class StartupTimingObserver(BaseObserver):
"""Observer that measures processor startup times during pipeline initialization.
Tracks how long each processor's ``start()`` method takes by measuring the
time between when a ``StartFrame`` arrives at a processor and when it is
pushed downstream. This captures WebSocket connections, API authentication,
model loading, and other initialization work.
By default, internal pipeline processors (``PipelineSource``, ``PipelineSink``,
``Pipeline``) are excluded from the report. Pass ``processor_types`` to
measure only specific types.
Event handlers available:
- on_startup_timing_report: Called once after startup completes with the full
timing report.
Example::
observer = StartupTimingObserver(
processor_types=(STTService, TTSService)
)
@observer.event_handler("on_startup_timing_report")
async def on_report(observer, report):
for t in report.processor_timings:
logger.info(f"{t.processor_name}: {t.duration_secs:.3f}s")
task = PipelineTask(pipeline, observers=[observer])
Args:
processor_types: Optional tuple of processor types to measure. If None,
all non-internal processors are measured.
"""
def __init__(
self,
*,
processor_types: Optional[Tuple[Type[FrameProcessor], ...]] = None,
**kwargs,
):
"""Initialize the startup timing observer.
Args:
processor_types: Optional tuple of processor types to measure.
If None, all non-internal processors are measured.
**kwargs: Additional arguments passed to parent class.
"""
super().__init__(**kwargs)
self._processor_types = processor_types
# Map processor ID -> (processor, arrival_timestamp_ns)
self._arrivals: Dict[int, Tuple[FrameProcessor, int]] = {}
# Collected timings in pipeline order.
self._timings: List[ProcessorStartupTiming] = []
# Lock onto the first StartFrame we see (by frame ID).
self._start_frame_id: Optional[str] = None
# Whether we've already emitted the report.
self._reported = False
self._register_event_handler("on_startup_timing_report")
def _should_track(self, processor: FrameProcessor) -> bool:
"""Check if a processor should be tracked for timing.
Args:
processor: The processor to check.
Returns:
True if the processor matches the filter or no filter is set.
"""
if self._processor_types is not None:
return isinstance(processor, self._processor_types)
# Default: exclude internal pipeline plumbing.
return not isinstance(processor, _INTERNAL_TYPES)
async def on_process_frame(self, data: FrameProcessed):
"""Record when a StartFrame arrives at a processor.
When a ``StartFrame`` reaches a ``PipelineSink``, startup is complete
(the frame has traversed the entire pipeline) and the report is emitted.
Args:
data: The frame processing event data.
"""
if self._reported:
return
if not isinstance(data.frame, StartFrame):
return
if data.direction != FrameDirection.DOWNSTREAM:
return
# Lock onto the first StartFrame.
if self._start_frame_id is None:
self._start_frame_id = data.frame.id
elif data.frame.id != self._start_frame_id:
return
# When the StartFrame reaches a PipelineSink, all processors have
# completed start(). PipelineSinks use direct mode so the outermost
# sink fires last within the same synchronous call chain.
if isinstance(data.processor, PipelineSink):
if self._timings:
await self._emit_report()
return
if self._should_track(data.processor):
self._arrivals[data.processor.id] = (data.processor, data.timestamp)
async def on_push_frame(self, data: FramePushed):
"""Record when a StartFrame leaves a processor and compute the delta.
Args:
data: The frame push event data.
"""
if self._reported:
return
if not isinstance(data.frame, StartFrame):
return
if data.direction != FrameDirection.DOWNSTREAM:
return
if self._start_frame_id is not None and data.frame.id != self._start_frame_id:
return
arrival = self._arrivals.pop(data.source.id, None)
if arrival is None:
return
processor, arrival_ts = arrival
duration_ns = data.timestamp - arrival_ts
duration_secs = duration_ns / 1e9
self._timings.append(
ProcessorStartupTiming(
processor_name=processor.name,
duration_secs=duration_secs,
)
)
async def _emit_report(self):
"""Build and emit the startup timing report."""
if self._reported:
return
self._reported = True
total = sum(t.duration_secs for t in self._timings)
report = StartupTimingReport(
total_duration_secs=total,
processor_timings=self._timings,
)
logger.debug(f"Pipeline startup completed in {total:.3f}s")
for t in self._timings:
logger.debug(f" {t.processor_name}: {t.duration_secs:.3f}s")
await self._call_event_handler("on_startup_timing_report", report)

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@@ -0,0 +1,186 @@
import asyncio
import unittest
from pipecat.frames.frames import Frame, StartFrame, TextFrame
from pipecat.observers.startup_timing_observer import (
StartupTimingObserver,
StartupTimingReport,
)
from pipecat.processors.frame_processor import FrameDirection, FrameProcessor
from pipecat.tests.utils import run_test
class SlowStartProcessor(FrameProcessor):
"""A processor that sleeps during start to simulate slow initialization."""
def __init__(self, delay: float = 0.1, **kwargs):
super().__init__(**kwargs)
self._delay = delay
async def process_frame(self, frame: Frame, direction: FrameDirection):
await super().process_frame(frame, direction)
if isinstance(frame, StartFrame):
await asyncio.sleep(self._delay)
await self.push_frame(frame, direction)
class FastProcessor(FrameProcessor):
"""A processor with no start delay."""
async def process_frame(self, frame: Frame, direction: FrameDirection):
await super().process_frame(frame, direction)
await self.push_frame(frame, direction)
class TestStartupTimingObserver(unittest.IsolatedAsyncioTestCase):
"""Tests for StartupTimingObserver."""
async def test_timing_reported(self):
"""Test that startup timing is measured and reported."""
observer = StartupTimingObserver()
processor = SlowStartProcessor(delay=0.1)
reports = []
@observer.event_handler("on_startup_timing_report")
async def on_report(obs, report):
reports.append(report)
frames_to_send = [TextFrame(text="hello")]
await run_test(
processor,
frames_to_send=frames_to_send,
expected_down_frames=[TextFrame],
observers=[observer],
)
self.assertEqual(len(reports), 1)
report = reports[0]
self.assertGreater(report.total_duration_secs, 0)
self.assertGreater(len(report.processor_timings), 0)
# Find our slow processor in the timings.
slow_timings = [
t for t in report.processor_timings if "SlowStartProcessor" in t.processor_name
]
self.assertEqual(len(slow_timings), 1)
self.assertGreaterEqual(slow_timings[0].duration_secs, 0.05)
async def test_processor_types_filter(self):
"""Test that processor_types filter limits which processors appear."""
observer = StartupTimingObserver(processor_types=(SlowStartProcessor,))
processor = SlowStartProcessor(delay=0.05)
reports = []
@observer.event_handler("on_startup_timing_report")
async def on_report(obs, report):
reports.append(report)
frames_to_send = [TextFrame(text="hello")]
await run_test(
processor,
frames_to_send=frames_to_send,
expected_down_frames=[TextFrame],
observers=[observer],
)
self.assertEqual(len(reports), 1)
report = reports[0]
# Only SlowStartProcessor should be in the timings.
for t in report.processor_timings:
self.assertIn("SlowStartProcessor", t.processor_name)
async def test_report_emits_once(self):
"""Test that the report is emitted only once even with multiple frames."""
observer = StartupTimingObserver()
processor = FastProcessor()
reports = []
@observer.event_handler("on_startup_timing_report")
async def on_report(obs, report):
reports.append(report)
frames_to_send = [
TextFrame(text="first"),
TextFrame(text="second"),
TextFrame(text="third"),
]
await run_test(
processor,
frames_to_send=frames_to_send,
expected_down_frames=[TextFrame, TextFrame, TextFrame],
observers=[observer],
)
self.assertEqual(len(reports), 1)
async def test_event_handler_receives_report(self):
"""Test that the event handler receives a proper StartupTimingReport."""
observer = StartupTimingObserver()
processor = SlowStartProcessor(delay=0.05)
reports = []
@observer.event_handler("on_startup_timing_report")
async def on_report(obs, report):
reports.append(report)
frames_to_send = [TextFrame(text="hello")]
await run_test(
processor,
frames_to_send=frames_to_send,
expected_down_frames=[TextFrame],
observers=[observer],
)
self.assertEqual(len(reports), 1)
report = reports[0]
self.assertIsInstance(report, StartupTimingReport)
self.assertIsInstance(report.total_duration_secs, float)
for timing in report.processor_timings:
self.assertIsInstance(timing.processor_name, str)
self.assertIsInstance(timing.duration_secs, float)
async def test_excludes_internal_processors(self):
"""Test that internal pipeline processors are excluded by default."""
observer = StartupTimingObserver()
processor = FastProcessor()
reports = []
@observer.event_handler("on_startup_timing_report")
async def on_report(obs, report):
reports.append(report)
frames_to_send = [TextFrame(text="hello")]
await run_test(
processor,
frames_to_send=frames_to_send,
expected_down_frames=[TextFrame],
observers=[observer],
)
self.assertEqual(len(reports), 1)
report = reports[0]
# No internal processors (PipelineSource, PipelineSink, Pipeline) in the report.
internal_names = ("Pipeline#", "PipelineTask#")
for t in report.processor_timings:
for prefix in internal_names:
self.assertNotIn(
prefix,
t.processor_name,
f"Internal processor {t.processor_name} should be excluded by default",
)
if __name__ == "__main__":
unittest.main()