vllm/vllm/engine/metrics.py

174 lines
6.9 KiB
Python

from vllm.logger import init_logger
from aioprometheus import Counter, Gauge, Histogram
import time
import numpy as np
from typing import List
from dataclasses import dataclass
logger = init_logger(__name__)
labels = {}
def add_global_metrics_labels(**kwargs):
labels.update(kwargs)
# The begin-* and end* here are used by the documentation generator
# to extract the metrics definitions.
# begin-metrics-definitions
gauge_avg_prompt_throughput = Gauge("vllm:avg_prompt_throughput_toks_per_s",
"Average prefill throughput in tokens/s.")
gauge_avg_generation_throughput = Gauge(
"vllm:avg_generation_throughput_toks_per_s",
"Average generation throughput in tokens/s.")
counter_prompt_tokens = Counter("vllm:prompt_tokens_total",
"Number of prefill tokens processed.")
counter_generation_tokens = Counter("vllm:generation_tokens_total",
"Number of generation tokens processed.")
gauge_scheduler_running = Gauge(
"vllm:num_requests_running",
"Number of requests currently running on GPU.")
gauge_scheduler_swapped = Gauge("vllm:num_requests_swapped",
"Number of requests swapped to CPU.")
gauge_scheduler_waiting = Gauge("vllm:num_requests_waiting",
"Number of requests waiting to be processed.")
gauge_gpu_cache_usage = Gauge(
"vllm:gpu_cache_usage_perc",
"GPU KV-cache usage. 1 means 100 percent usage.")
gauge_cpu_cache_usage = Gauge(
"vllm:cpu_cache_usage_perc",
"CPU KV-cache usage. 1 means 100 percent usage.")
histogram_time_to_first_token = Histogram(
"vllm:time_to_first_token_seconds",
"Histogram of time to first token in seconds.",
buckets=[
0.001, 0.005, 0.01, 0.02, 0.04, 0.06, 0.08, 0.1, 0.25, 0.5, 0.75, 1.0,
2.5, 5.0, 7.5, 10.0
])
histogram_time_per_output_tokens = Histogram(
"vllm:time_per_output_token_seconds",
"Histogram of time per output token in seconds.",
buckets=[
0.01, 0.025, 0.05, 0.075, 0.1, 0.15, 0.2, 0.3, 0.4, 0.5, 0.75, 1.0, 2.5
])
histogram_e2e_request_latency = Histogram(
"vllm:e2e_request_latency_seconds",
"Histogram of end to end request latency in seconds.",
buckets=[1.0, 2.5, 5.0, 10.0, 15.0, 20.0, 30.0, 40.0, 50.0, 60.0])
# end-metrics-definitions
@dataclass
class Stats:
"""Created by LLMEngine for use by StatLogger."""
now: float
# System stats.
num_running: int
num_waiting: int
num_swapped: int
gpu_cache_usage: float
cpu_cache_usage: float
# Raw stats from last model iteration.
num_prompt_tokens: int
num_generation_tokens: int
time_to_first_tokens: List[float]
time_per_output_tokens: List[float]
time_e2e_requests: List[float]
class StatLogger:
"""StatLogger is used LLMEngine to log to Promethus and Stdout."""
def __init__(self, local_interval: float) -> None:
# Metadata for logging locally.
self.last_local_log = time.monotonic()
self.local_interval = local_interval
# Tracked stats over current local logging interval.
self.num_prompt_tokens: List[int] = []
self.num_generation_tokens: List[int] = []
def _get_throughput(self, tracked_stats: List[int], now: float) -> float:
return float(np.sum(tracked_stats) / (now - self.last_local_log))
def _local_interval_elapsed(self, now: float) -> bool:
elapsed_time = now - self.last_local_log
return elapsed_time > self.local_interval
def _log_prometheus(self, stats: Stats) -> None:
# Set system stat gauges.
gauge_scheduler_running.set(labels, stats.num_running)
gauge_scheduler_swapped.set(labels, stats.num_swapped)
gauge_scheduler_waiting.set(labels, stats.num_waiting)
gauge_gpu_cache_usage.set(labels, stats.gpu_cache_usage)
gauge_cpu_cache_usage.set(labels, stats.cpu_cache_usage)
# Add to token counters.
counter_prompt_tokens.add(labels, stats.num_prompt_tokens)
counter_generation_tokens.add(labels, stats.num_generation_tokens)
# Observe request level latencies in histograms.
for ttft in stats.time_to_first_tokens:
histogram_time_to_first_token.observe(labels, ttft)
for tpot in stats.time_per_output_tokens:
histogram_time_per_output_tokens.observe(labels, tpot)
for e2e in stats.time_e2e_requests:
histogram_e2e_request_latency.observe(labels, e2e)
def _log_prometheus_interval(self, prompt_throughput: float,
generation_throughput: float) -> None:
# Logs metrics to prometheus that are computed every logging_interval.
# Support legacy gauge metrics that make throughput calculations on the vLLM side.
# Moving forward, we should use counters like counter_prompt_tokens, counter_generation_tokens
# Which log raw data and calculate summaries using rate() on the grafana/prometheus side.
# See https://github.com/vllm-project/vllm/pull/2316#discussion_r1464204666
gauge_avg_prompt_throughput.set(labels, prompt_throughput)
gauge_avg_generation_throughput.set(labels, generation_throughput)
def log(self, stats: Stats) -> None:
"""Called by LLMEngine.
Logs to prometheus and tracked stats every iteration.
Logs to Stdout every self.local_interval seconds."""
# Log to prometheus.
self._log_prometheus(stats)
# Save tracked stats for token counters.
self.num_prompt_tokens.append(stats.num_prompt_tokens)
self.num_generation_tokens.append(stats.num_generation_tokens)
# Log locally every local_interval seconds.
if self._local_interval_elapsed(stats.now):
# Compute summary metrics for tracked stats (and log them to promethus if applicable).
prompt_throughput = self._get_throughput(self.num_prompt_tokens,
now=stats.now)
generation_throughput = self._get_throughput(
self.num_generation_tokens, now=stats.now)
self._log_prometheus_interval(
prompt_throughput=prompt_throughput,
generation_throughput=generation_throughput)
# Log to stdout.
logger.info(
f"Avg prompt throughput: {prompt_throughput:.1f} tokens/s, "
f"Avg generation throughput: {generation_throughput:.1f} tokens/s, "
f"Running: {stats.num_running} reqs, "
f"Swapped: {stats.num_swapped} reqs, "
f"Pending: {stats.num_waiting} reqs, "
f"GPU KV cache usage: {stats.gpu_cache_usage * 100:.1f}%, "
f"CPU KV cache usage: {stats.cpu_cache_usage * 100:.1f}%")
# Reset tracked stats for next interval.
self.num_prompt_tokens = []
self.num_generation_tokens = []
self.last_local_log = stats.now