fleet-memory/hindsight-api/hindsight_api/metrics.py
Nicolò Boschi 5e1f13e4f2
feat: add metrics for llm call latency (#120)
* feat: add metrics for llm call latency

* feat: add metrics for llm call latency

* fix
2026-01-08 11:40:34 +01:00

365 lines
11 KiB
Python

"""
OpenTelemetry metrics instrumentation for Hindsight API.
This module provides metrics for:
- Operation latency (retain, recall, reflect) with percentiles
- Token usage (input/output) per operation
- Per-bank granularity via labels
- LLM call latency and token usage with scope dimension
"""
import logging
import time
from contextlib import contextmanager
from opentelemetry import metrics
from opentelemetry.exporter.prometheus import PrometheusMetricReader
from opentelemetry.sdk.metrics import MeterProvider
from opentelemetry.sdk.metrics.view import ExplicitBucketHistogramAggregation, View
from opentelemetry.sdk.resources import Resource
# Custom bucket boundaries for operation duration (in seconds)
# Fine granularity in 0-30s range where most operations complete
DURATION_BUCKETS = (0.1, 0.25, 0.5, 0.75, 1.0, 2.0, 3.0, 5.0, 7.5, 10.0, 15.0, 20.0, 30.0, 60.0, 120.0)
# LLM duration buckets (finer granularity for faster LLM calls)
LLM_DURATION_BUCKETS = (0.1, 0.25, 0.5, 1.0, 2.0, 3.0, 5.0, 10.0, 15.0, 30.0, 60.0, 120.0)
def get_token_bucket(token_count: int) -> str:
"""
Convert a token count to a bucket label for use as a dimension.
This allows analyzing token usage patterns without high-cardinality issues.
Buckets:
- "0-100": Very small requests/responses
- "100-500": Small requests/responses
- "500-1k": Medium requests/responses
- "1k-5k": Large requests/responses
- "5k-10k": Very large requests/responses
- "10k-50k": Huge requests/responses
- "50k+": Extremely large requests/responses
Args:
token_count: Number of tokens
Returns:
Bucket label string
"""
if token_count < 100:
return "0-100"
elif token_count < 500:
return "100-500"
elif token_count < 1000:
return "500-1k"
elif token_count < 5000:
return "1k-5k"
elif token_count < 10000:
return "5k-10k"
elif token_count < 50000:
return "10k-50k"
else:
return "50k+"
logger = logging.getLogger(__name__)
# Global meter instance
_meter = None
def initialize_metrics(service_name: str = "hindsight-api", service_version: str = "1.0.0"):
"""
Initialize OpenTelemetry metrics with Prometheus exporter.
This should be called once during application startup.
Args:
service_name: Name of the service for resource attributes
service_version: Version of the service
Returns:
PrometheusMetricReader instance (for accessing metrics endpoint)
"""
global _meter
# Create resource with service information
resource = Resource.create(
{
"service.name": service_name,
"service.version": service_version,
}
)
# Create Prometheus metric reader
prometheus_reader = PrometheusMetricReader()
# Create view with custom bucket boundaries for duration histogram
duration_view = View(
instrument_name="hindsight.operation.duration",
aggregation=ExplicitBucketHistogramAggregation(boundaries=DURATION_BUCKETS),
)
# Create view with custom bucket boundaries for LLM duration histogram
llm_duration_view = View(
instrument_name="hindsight.llm.duration",
aggregation=ExplicitBucketHistogramAggregation(boundaries=LLM_DURATION_BUCKETS),
)
# Create meter provider with Prometheus exporter and custom views
provider = MeterProvider(
resource=resource, metric_readers=[prometheus_reader], views=[duration_view, llm_duration_view]
)
# Set the global meter provider
metrics.set_meter_provider(provider)
# Get meter for this application
_meter = metrics.get_meter(__name__)
return prometheus_reader
def get_meter():
"""Get the global meter instance."""
if _meter is None:
raise RuntimeError("Metrics not initialized. Call initialize_metrics() first.")
return _meter
class MetricsCollectorBase:
"""Base class for metrics collectors."""
@contextmanager
def record_operation(
self,
operation: str,
bank_id: str,
source: str = "api",
budget: str | None = None,
max_tokens: int | None = None,
):
"""Context manager to record operation duration and status."""
raise NotImplementedError
def record_llm_call(
self,
provider: str,
model: str,
scope: str,
duration: float,
input_tokens: int = 0,
output_tokens: int = 0,
success: bool = True,
):
"""
Record metrics for an LLM call.
Args:
provider: LLM provider name (openai, anthropic, gemini, groq, ollama, lmstudio)
model: Model name
scope: Scope identifier (e.g., "memory", "reflect", "entity_observation")
duration: Call duration in seconds
input_tokens: Number of input/prompt tokens
output_tokens: Number of output/completion tokens
success: Whether the call was successful
"""
raise NotImplementedError
class NoOpMetricsCollector(MetricsCollectorBase):
"""No-op metrics collector that does nothing. Used when metrics are disabled."""
@contextmanager
def record_operation(
self,
operation: str,
bank_id: str,
source: str = "api",
budget: str | None = None,
max_tokens: int | None = None,
):
"""No-op context manager."""
yield
def record_llm_call(
self,
provider: str,
model: str,
scope: str,
duration: float,
input_tokens: int = 0,
output_tokens: int = 0,
success: bool = True,
):
"""No-op LLM call recording."""
pass
class MetricsCollector(MetricsCollectorBase):
"""
Collector for Hindsight API metrics.
Provides methods to record latency and token usage for operations.
"""
def __init__(self):
self.meter = get_meter()
# Operation latency histogram (in seconds)
# Records duration of retain, recall, reflect operations
self.operation_duration = self.meter.create_histogram(
name="hindsight.operation.duration", description="Duration of Hindsight operations in seconds", unit="s"
)
# Operation counter (success/failure)
self.operation_total = self.meter.create_counter(
name="hindsight.operation.total", description="Total number of operations executed", unit="operations"
)
# LLM call latency histogram (in seconds)
# Records duration of LLM API calls with provider, model, and scope dimensions
self.llm_duration = self.meter.create_histogram(
name="hindsight.llm.duration", description="Duration of LLM API calls in seconds", unit="s"
)
# LLM token usage counters with bucket labels
self.llm_tokens_input = self.meter.create_counter(
name="hindsight.llm.tokens.input", description="Number of input tokens for LLM calls", unit="tokens"
)
self.llm_tokens_output = self.meter.create_counter(
name="hindsight.llm.tokens.output", description="Number of output tokens from LLM calls", unit="tokens"
)
# LLM call counter (success/failure)
self.llm_calls_total = self.meter.create_counter(
name="hindsight.llm.calls.total", description="Total number of LLM API calls", unit="calls"
)
@contextmanager
def record_operation(
self,
operation: str,
bank_id: str,
source: str = "api",
budget: str | None = None,
max_tokens: int | None = None,
):
"""
Context manager to record operation duration and status.
Usage:
with metrics.record_operation("recall", bank_id="user123", source="api", budget="mid", max_tokens=4096):
# ... perform operation
pass
Args:
operation: Operation name (retain, recall, reflect, entity_observation)
bank_id: Memory bank ID
source: Source of the operation (api, reflect, internal)
budget: Optional budget level (low, mid, high)
max_tokens: Optional max tokens for the operation
"""
start_time = time.time()
attributes = {
"operation": operation,
"bank_id": bank_id,
"source": source,
}
if budget:
attributes["budget"] = budget
if max_tokens:
attributes["max_tokens"] = str(max_tokens)
success = True
try:
yield
except Exception:
success = False
raise
finally:
duration = time.time() - start_time
attributes["success"] = str(success).lower()
# Record duration
self.operation_duration.record(duration, attributes)
# Record operation count
self.operation_total.add(1, attributes)
def record_llm_call(
self,
provider: str,
model: str,
scope: str,
duration: float,
input_tokens: int = 0,
output_tokens: int = 0,
success: bool = True,
):
"""
Record metrics for an LLM call.
Args:
provider: LLM provider name (openai, anthropic, gemini, groq, ollama, lmstudio)
model: Model name
scope: Scope identifier (e.g., "memory", "reflect", "entity_observation")
duration: Call duration in seconds
input_tokens: Number of input/prompt tokens
output_tokens: Number of output/completion tokens
success: Whether the call was successful
"""
# Base attributes for all metrics
base_attributes = {
"provider": provider,
"model": model,
"scope": scope,
"success": str(success).lower(),
}
# Record duration
self.llm_duration.record(duration, base_attributes)
# Record call count
self.llm_calls_total.add(1, base_attributes)
# Record tokens with bucket labels for cardinality control
if input_tokens > 0:
input_attributes = {
**base_attributes,
"token_bucket": get_token_bucket(input_tokens),
}
self.llm_tokens_input.add(input_tokens, input_attributes)
if output_tokens > 0:
output_attributes = {
**base_attributes,
"token_bucket": get_token_bucket(output_tokens),
}
self.llm_tokens_output.add(output_tokens, output_attributes)
# Global metrics collector instance (defaults to no-op)
_metrics_collector: MetricsCollectorBase = NoOpMetricsCollector()
def get_metrics_collector() -> MetricsCollectorBase:
"""
Get the global metrics collector instance.
Returns a no-op collector if metrics are not initialized.
"""
return _metrics_collector
def create_metrics_collector() -> MetricsCollector:
"""
Create and set the global metrics collector.
Should be called after initialize_metrics().
"""
global _metrics_collector
_metrics_collector = MetricsCollector()
return _metrics_collector