344 lines
13 KiB
Python
344 lines
13 KiB
Python
# ================================================================
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# shared/monitoring/metrics.py - FIXED VERSION
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# ================================================================
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"""
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Centralized metrics collection for microservices - Fixed middleware issue
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"""
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import time
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import logging
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from typing import Dict, Any, List, Optional
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from prometheus_client import Counter, Histogram, Gauge, start_http_server, generate_latest
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from fastapi import Request, Response
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from threading import Lock
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logger = logging.getLogger(__name__)
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# Global registry for metrics collectors
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_metrics_registry: Dict[str, 'MetricsCollector'] = {}
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_registry_lock = Lock()
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# Default Prometheus metrics
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DEFAULT_REQUEST_COUNT = Counter(
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'http_requests_total',
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'Total HTTP requests',
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['method', 'endpoint', 'status_code', 'service']
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)
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DEFAULT_REQUEST_DURATION = Histogram(
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'http_request_duration_seconds',
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'HTTP request duration in seconds',
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['method', 'endpoint', 'service']
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)
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DEFAULT_ACTIVE_CONNECTIONS = Gauge(
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'active_connections',
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'Active database connections',
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['service']
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)
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class MetricsCollector:
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"""Thread-safe metrics collector for microservices"""
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def __init__(self, service_name: str):
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self.service_name = service_name
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self.start_time = time.time()
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self._counters: Dict[str, Counter] = {}
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self._histograms: Dict[str, Histogram] = {}
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self._gauges: Dict[str, Gauge] = {}
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self._lock = Lock()
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# Register in global registry
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with _registry_lock:
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_metrics_registry[service_name] = self
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def start_metrics_server(self, port: int = 8080):
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"""Start Prometheus metrics server"""
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try:
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start_http_server(port)
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logger.info(f"Metrics server started on port {port} for {self.service_name}")
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except Exception as e:
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logger.error(f"Failed to start metrics server for {self.service_name}: {e}")
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def register_counter(self, name: str, documentation: str, labels: List[str] = None) -> Counter:
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"""Register a custom Counter metric."""
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with self._lock:
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if name in self._counters:
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logger.warning(f"Counter '{name}' already registered for {self.service_name}")
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return self._counters[name]
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if labels is None:
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labels = ['service']
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elif 'service' not in labels:
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labels.append('service')
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try:
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counter = Counter(f"{self.service_name.replace('-', '_')}_{name}", documentation, labelnames=labels)
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self._counters[name] = counter
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logger.info(f"Registered counter: {name} for {self.service_name}")
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return counter
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except Exception as e:
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logger.error(f"Failed to register counter {name} for {self.service_name}: {e}")
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raise
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def register_histogram(self, name: str, documentation: str, labels: List[str] = None,
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buckets: tuple = Histogram.DEFAULT_BUCKETS) -> Histogram:
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"""Register a custom Histogram metric."""
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with self._lock:
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if name in self._histograms:
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logger.warning(f"Histogram '{name}' already registered for {self.service_name}")
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return self._histograms[name]
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if labels is None:
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labels = ['service']
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elif 'service' not in labels:
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labels.append('service')
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try:
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histogram = Histogram(f"{self.service_name.replace('-', '_')}_{name}", documentation,
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labelnames=labels, buckets=buckets)
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self._histograms[name] = histogram
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logger.info(f"Registered histogram: {name} for {self.service_name}")
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return histogram
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except ValueError as e:
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if "Duplicated timeseries" in str(e):
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# Metric already exists in global registry, try to find it
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from prometheus_client import REGISTRY
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metric_name = f"{self.service_name.replace('-', '_')}_{name}"
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for collector in REGISTRY._collector_to_names.keys():
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if hasattr(collector, '_name') and collector._name == metric_name:
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self._histograms[name] = collector
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logger.warning(f"Reusing existing histogram: {name} for {self.service_name}")
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return collector
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# If we can't find it, create a new name with suffix
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import time
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suffix = str(int(time.time() * 1000))[-6:] # Last 6 digits of timestamp
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histogram = Histogram(f"{self.service_name.replace('-', '_')}_{name}_{suffix}",
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documentation, labelnames=labels, buckets=buckets)
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self._histograms[name] = histogram
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logger.warning(f"Created histogram with suffix: {name}_{suffix} for {self.service_name}")
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return histogram
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else:
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logger.error(f"Failed to register histogram {name} for {self.service_name}: {e}")
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raise
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except Exception as e:
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logger.error(f"Failed to register histogram {name} for {self.service_name}: {e}")
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raise
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def register_gauge(self, name: str, documentation: str, labels: List[str] = None) -> Gauge:
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"""Register a custom Gauge metric."""
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with self._lock:
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if name in self._gauges:
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logger.warning(f"Gauge '{name}' already registered for {self.service_name}")
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return self._gauges[name]
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if labels is None:
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labels = ['service']
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elif 'service' not in labels:
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labels.append('service')
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try:
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gauge = Gauge(f"{self.service_name.replace('-', '_')}_{name}", documentation, labelnames=labels)
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self._gauges[name] = gauge
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logger.info(f"Registered gauge: {name} for {self.service_name}")
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return gauge
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except Exception as e:
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logger.error(f"Failed to register gauge {name} for {self.service_name}: {e}")
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raise
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def increment_counter(self, name: str, value: int = 1, labels: Dict[str, str] = None):
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"""Increment a counter metric."""
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if name not in self._counters:
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logger.error(f"Counter '{name}' not registered for {self.service_name}. Cannot increment.")
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return
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if labels is None:
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labels = {'service': self.service_name}
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elif 'service' not in labels:
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labels['service'] = self.service_name
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try:
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self._counters[name].labels(**labels).inc(value)
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except Exception as e:
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logger.error(f"Failed to increment counter {name} for {self.service_name}: {e}")
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def observe_histogram(self, name: str, value: float, labels: Dict[str, str] = None):
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"""Observe a histogram metric."""
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if name not in self._histograms:
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logger.error(f"Histogram '{name}' not registered for {self.service_name}. Cannot observe.")
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return
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if labels is None:
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labels = {'service': self.service_name}
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elif 'service' not in labels:
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labels['service'] = self.service_name
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try:
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self._histograms[name].labels(**labels).observe(value)
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except Exception as e:
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logger.error(f"Failed to observe histogram {name} for {self.service_name}: {e}")
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def set_gauge(self, name: str, value: float, labels: Dict[str, str] = None):
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"""Set a gauge metric."""
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if name not in self._gauges:
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logger.error(f"Gauge '{name}' not registered for {self.service_name}. Cannot set.")
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return
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if labels is None:
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labels = {'service': self.service_name}
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elif 'service' not in labels:
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labels['service'] = self.service_name
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try:
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self._gauges[name].labels(**labels).set(value)
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except Exception as e:
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logger.error(f"Failed to set gauge {name} for {self.service_name}: {e}")
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def record_request(self, method: str, endpoint: str, status_code: int, duration: float):
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"""Record HTTP request metrics using default metrics."""
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try:
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DEFAULT_REQUEST_COUNT.labels(
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method=method,
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endpoint=endpoint,
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status_code=status_code,
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service=self.service_name
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).inc()
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DEFAULT_REQUEST_DURATION.labels(
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method=method,
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endpoint=endpoint,
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service=self.service_name
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).observe(duration)
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except Exception as e:
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logger.error(f"Failed to record request metrics for {self.service_name}: {e}")
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def set_active_connections(self, count: int):
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"""Set active database connections using default gauge."""
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try:
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DEFAULT_ACTIVE_CONNECTIONS.labels(service=self.service_name).set(count)
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except Exception as e:
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logger.error(f"Failed to set active connections for {self.service_name}: {e}")
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def get_metrics(self) -> str:
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"""Return Prometheus metrics in exposition format."""
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try:
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return generate_latest().decode('utf-8')
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except Exception as e:
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logger.error(f"Failed to generate metrics for {self.service_name}: {e}")
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return ""
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def get_metrics_collector(service_name: str) -> Optional[MetricsCollector]:
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"""Get metrics collector by service name from global registry."""
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with _registry_lock:
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return _metrics_registry.get(service_name)
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def create_metrics_collector(service_name: str) -> MetricsCollector:
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"""
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Create metrics collector without adding middleware.
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This should be called BEFORE app startup, not during lifespan.
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"""
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# Get existing or create new
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existing = get_metrics_collector(service_name)
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if existing:
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return existing
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return MetricsCollector(service_name)
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def add_metrics_middleware(app, metrics_collector: MetricsCollector):
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"""
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Add metrics middleware to app. Must be called BEFORE app startup.
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"""
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@app.middleware("http")
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async def metrics_middleware(request: Request, call_next):
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start_time = time.time()
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try:
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response = await call_next(request)
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duration = time.time() - start_time
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# Record request metrics
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metrics_collector.record_request(
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method=request.method,
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endpoint=request.url.path,
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status_code=response.status_code,
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duration=duration
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)
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return response
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except Exception as e:
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duration = time.time() - start_time
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# Record failed request
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metrics_collector.record_request(
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method=request.method,
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endpoint=request.url.path,
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status_code=500,
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duration=duration
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)
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raise
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return metrics_collector
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def add_metrics_endpoint(app, metrics_collector: MetricsCollector):
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"""Add metrics endpoint to app"""
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@app.get("/metrics")
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async def prometheus_metrics():
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"""Prometheus metrics endpoint"""
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return Response(
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content=metrics_collector.get_metrics(),
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media_type="text/plain; version=0.0.4; charset=utf-8"
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)
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def setup_metrics_early(app, service_name: str = None) -> MetricsCollector:
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"""
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Setup metrics collection BEFORE app startup.
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This must be called before adding any middleware or starting the app.
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"""
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if service_name is None:
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service_name = getattr(app, 'title', 'unknown-service').lower().replace(' ', '-').replace('.', '_')
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# Create metrics collector
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metrics_collector = create_metrics_collector(service_name)
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# Add middleware (must be before app starts)
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add_metrics_middleware(app, metrics_collector)
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# Add metrics endpoint
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add_metrics_endpoint(app, metrics_collector)
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# Store in app state for access from routes
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app.state.metrics_collector = metrics_collector
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logger.info(f"Metrics setup completed for service: {service_name}")
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return metrics_collector
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# Additional helper function for endpoint tracking
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def track_endpoint_metrics(endpoint_name: str = None, service_name: str = None):
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"""Decorator for tracking endpoint metrics - Fixed for async functions"""
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def decorator(func):
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import asyncio
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from functools import wraps
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@wraps(func)
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async def async_wrapper(*args, **kwargs):
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# For now, just pass through - metrics are handled by middleware
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return await func(*args, **kwargs)
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@wraps(func)
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def sync_wrapper(*args, **kwargs):
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# For now, just pass through - metrics are handled by middleware
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return func(*args, **kwargs)
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# Return appropriate wrapper based on function type
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if asyncio.iscoroutinefunction(func):
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return async_wrapper
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else:
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return sync_wrapper
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return decorator
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