TensorRT-LLM 实战经验与最佳实践
1. 性能优化实战
1.1 内存优化策略
KV 缓存优化
# 最佳实践:启用 KV 缓存块重用
from tensorrt_llm.llmapi import KvCacheConfig
kv_cache_config = KvCacheConfig(
free_gpu_memory_fraction=0.85, # 为 KV 缓存预留 85% GPU 内存
enable_block_reuse=True, # 启用块重用,提高缓存效率
max_tokens_in_paged_kv_cache=None, # 自动计算最大 token 数
kv_cache_free_gpu_memory_fraction=0.9 # KV 缓存内存分配比例
)
# 实战经验:根据模型大小调整内存分配
def get_optimal_kv_cache_config(model_size_gb: float, gpu_memory_gb: float):
"""根据模型大小和 GPU 内存优化 KV 缓存配置"""
if model_size_gb <= 7: # 7B 模型
return KvCacheConfig(
free_gpu_memory_fraction=0.9,
enable_block_reuse=True
)
elif model_size_gb <= 13: # 13B 模型
return KvCacheConfig(
free_gpu_memory_fraction=0.8,
enable_block_reuse=True
)
else: # 更大模型
return KvCacheConfig(
free_gpu_memory_fraction=0.7,
enable_block_reuse=True
)
批次大小优化
def find_optimal_batch_size(model_path: str, max_seq_len: int, gpu_memory_gb: float):
"""动态寻找最优批次大小"""
# 基于 GPU 内存的初始估算
base_batch_size = max(1, int(gpu_memory_gb / 4)) # 保守估算
# 二分搜索最优批次大小
low, high = 1, base_batch_size * 2
optimal_batch_size = 1
while low <= high:
mid = (low + high) // 2
try:
# 测试批次大小
build_config = BuildConfig(
max_batch_size=mid,
max_seq_len=max_seq_len,
max_input_len=max_seq_len // 2
)
# 尝试构建引擎(dry run)
build_config.dry_run = True
test_build(model_path, build_config)
optimal_batch_size = mid
low = mid + 1
except torch.cuda.OutOfMemoryError:
high = mid - 1
return optimal_batch_size
# 实战配置示例
def create_production_build_config(model_size: str, use_case: str):
"""生产环境构建配置"""
configs = {
"7b_chat": BuildConfig(
max_batch_size=32,
max_seq_len=4096,
max_input_len=2048,
max_beam_width=4,
strongly_typed=True,
use_refit=True, # 支持权重更新
weight_streaming=False
),
"13b_chat": BuildConfig(
max_batch_size=16,
max_seq_len=4096,
max_input_len=2048,
max_beam_width=2,
strongly_typed=True,
use_refit=True,
weight_streaming=True # 大模型启用权重流式传输
),
"70b_inference": BuildConfig(
max_batch_size=4,
max_seq_len=2048,
max_input_len=1024,
max_beam_width=1,
strongly_typed=True,
weight_streaming=True,
use_strip_plan=True # 减少引擎大小
)
}
return configs.get(f"{model_size}_{use_case}", configs["7b_chat"])
1.2 并行策略优化
张量并行最佳实践
def calculate_optimal_tp_size(model_params: int, num_gpus: int, gpu_memory_gb: float):
"""计算最优张量并行大小"""
# 模型参数量到内存需求的映射(GB)
model_memory_gb = model_params * 2 / 1e9 # FP16 权重
# 单卡能否容纳模型
if model_memory_gb <= gpu_memory_gb * 0.7:
return 1 # 单卡足够
# 计算最小需要的 GPU 数量
min_gpus = math.ceil(model_memory_gb / (gpu_memory_gb * 0.7))
# 选择合适的 TP 大小(必须是 num_gpus 的因子)
possible_tp_sizes = [i for i in [1, 2, 4, 8] if i <= num_gpus and num_gpus % i == 0]
for tp_size in possible_tp_sizes:
if tp_size >= min_gpus:
return tp_size
return min(possible_tp_sizes[-1], num_gpus)
# 实战配置示例
class ParallelismConfig:
"""并行策略配置类"""
@staticmethod
def get_config(model_name: str, num_gpus: int):
"""获取并行配置"""
configs = {
"llama-7b": {
1: {"tp": 1, "pp": 1},
2: {"tp": 2, "pp": 1},
4: {"tp": 4, "pp": 1},
8: {"tp": 8, "pp": 1}
},
"llama-13b": {
2: {"tp": 2, "pp": 1},
4: {"tp": 4, "pp": 1},
8: {"tp": 8, "pp": 1}
},
"llama-70b": {
4: {"tp": 4, "pp": 1},
8: {"tp": 8, "pp": 1},
16: {"tp": 8, "pp": 2} # 混合并行
},
"mixtral-8x7b": {
4: {"tp": 2, "pp": 1, "ep": 2}, # 专家并行
8: {"tp": 4, "pp": 1, "ep": 2}
}
}
return configs.get(model_name, {}).get(num_gpus, {"tp": 1, "pp": 1})
# 使用示例
def create_parallel_llm(model_path: str, num_gpus: int):
"""创建并行 LLM 实例"""
model_name = extract_model_name(model_path)
config = ParallelismConfig.get_config(model_name, num_gpus)
llm = LLM(
model=model_path,
tensor_parallel_size=config["tp"],
pipeline_parallel_size=config.get("pp", 1),
moe_expert_parallel_size=config.get("ep", None)
)
return llm
1.3 量化策略优化
量化算法选择
def select_quantization_strategy(model_size_gb: float, target_latency_ms: float, accuracy_threshold: float):
"""选择最优量化策略"""
strategies = []
# FP8 量化 - 最佳性能,轻微精度损失
if target_latency_ms < 50:
strategies.append({
"algo": QuantAlgo.FP8,
"expected_speedup": 1.8,
"accuracy_loss": 0.02,
"memory_reduction": 0.5
})
# INT4 AWQ - 平衡性能和精度
if model_size_gb > 10:
strategies.append({
"algo": QuantAlgo.W4A16_AWQ,
"expected_speedup": 1.4,
"accuracy_loss": 0.05,
"memory_reduction": 0.75
})
# FP4 量化 - 最大压缩(B200 GPU)
if model_size_gb > 20:
strategies.append({
"algo": QuantAlgo.NVFP4,
"expected_speedup": 2.0,
"accuracy_loss": 0.08,
"memory_reduction": 0.875
})
# 选择最佳策略
best_strategy = None
for strategy in strategies:
if strategy["accuracy_loss"] <= (1 - accuracy_threshold):
if best_strategy is None or strategy["expected_speedup"] > best_strategy["expected_speedup"]:
best_strategy = strategy
return best_strategy["algo"] if best_strategy else QuantAlgo.NO_QUANT
# 实战量化配置
def create_production_quant_config(model_path: str, target_use_case: str):
"""生产环境量化配置"""
use_case_configs = {
"high_throughput": {
"quant_algo": QuantAlgo.FP8,
"kv_cache_quant_algo": QuantAlgo.FP8,
"group_size": 128
},
"memory_constrained": {
"quant_algo": QuantAlgo.W4A16_AWQ,
"kv_cache_quant_algo": QuantAlgo.INT8,
"group_size": 64
},
"balanced": {
"quant_algo": QuantAlgo.W8A8_SQ_PER_CHANNEL,
"kv_cache_quant_algo": QuantAlgo.INT8,
"group_size": 128
}
}
config_dict = use_case_configs.get(target_use_case, use_case_configs["balanced"])
return QuantConfig(
quant_algo=config_dict["quant_algo"],
kv_cache_quant_algo=config_dict["kv_cache_quant_algo"],
group_size=config_dict["group_size"],
calib_size=512,
calib_dataset="cnn_dailymail"
)
2. 部署实战经验
2.1 生产环境部署
Docker 容器化部署
# 生产级 Dockerfile
FROM nvcr.io/nvidia/tensorrt:24.05-py3
# 安装 TensorRT-LLM
RUN pip install tensorrt-llm --extra-index-url https://pypi.nvidia.com
# 设置环境变量
ENV CUDA_VISIBLE_DEVICES=0,1,2,3
ENV NCCL_DEBUG=INFO
ENV NCCL_IB_DISABLE=1
# 创建工作目录
WORKDIR /app
# 复制模型和配置
COPY models/ /app/models/
COPY configs/ /app/configs/
COPY scripts/ /app/scripts/
# 设置启动脚本
COPY entrypoint.sh /app/
RUN chmod +x /app/entrypoint.sh
ENTRYPOINT ["/app/entrypoint.sh"]
#!/bin/bash
# entrypoint.sh - 生产启动脚本
set -e
# 环境检查
echo "Checking GPU availability..."
nvidia-smi
# 模型路径检查
if [ ! -d "/app/models" ]; then
echo "Error: Models directory not found"
exit 1
fi
# 启动参数配置
MODEL_PATH=${MODEL_PATH:-"/app/models/llama-7b"}
TP_SIZE=${TP_SIZE:-1}
MAX_BATCH_SIZE=${MAX_BATCH_SIZE:-32}
MAX_SEQ_LEN=${MAX_SEQ_LEN:-4096}
# 健康检查端点
python -c "
import torch
print(f'PyTorch version: {torch.__version__}')
print(f'CUDA available: {torch.cuda.is_available()}')
print(f'GPU count: {torch.cuda.device_count()}')
"
# 启动服务
exec trtllm-serve \
--model "$MODEL_PATH" \
--tp_size "$TP_SIZE" \
--max_batch_size "$MAX_BATCH_SIZE" \
--max_seq_len "$MAX_SEQ_LEN" \
--host 0.0.0.0 \
--port 8000
Kubernetes 部署配置
# k8s-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: trtllm-service
labels:
app: trtllm-service
spec:
replicas: 2
selector:
matchLabels:
app: trtllm-service
template:
metadata:
labels:
app: trtllm-service
spec:
containers:
- name: trtllm-container
image: your-registry/trtllm:latest
ports:
- containerPort: 8000
env:
- name: MODEL_PATH
value: "/models/llama-7b"
- name: TP_SIZE
value: "2"
- name: MAX_BATCH_SIZE
value: "16"
resources:
requests:
nvidia.com/gpu: 2
memory: "16Gi"
cpu: "4"
limits:
nvidia.com/gpu: 2
memory: "32Gi"
cpu: "8"
volumeMounts:
- name: model-storage
mountPath: /models
livenessProbe:
httpGet:
path: /health
port: 8000
initialDelaySeconds: 60
periodSeconds: 30
readinessProbe:
httpGet:
path: /health
port: 8000
initialDelaySeconds: 30
periodSeconds: 10
volumes:
- name: model-storage
persistentVolumeClaim:
claimName: model-pvc
nodeSelector:
accelerator: nvidia-tesla-v100
---
apiVersion: v1
kind: Service
metadata:
name: trtllm-service
spec:
selector:
app: trtllm-service
ports:
- protocol: TCP
port: 80
targetPort: 8000
type: LoadBalancer
2.2 监控和日志
性能监控
import time
import psutil
import torch
from typing import Dict, Any
import logging
class TRTLLMMonitor:
"""TensorRT-LLM 性能监控器"""
def __init__(self, llm):
self.llm = llm
self.metrics = {
"requests_total": 0,
"requests_success": 0,
"requests_failed": 0,
"total_tokens_generated": 0,
"total_inference_time": 0.0,
"gpu_memory_usage": [],
"cpu_usage": [],
"throughput_history": []
}
# 设置日志
logging.basicConfig(
level=logging.INFO,
format='%(asctime)s - %(levelname)s - %(message)s',
handlers=[
logging.FileHandler('trtllm_performance.log'),
logging.StreamHandler()
]
)
self.logger = logging.getLogger(__name__)
def monitor_request(self, inputs: str, sampling_params: Any) -> Dict[str, Any]:
"""监控单个请求的性能"""
start_time = time.time()
start_memory = torch.cuda.memory_allocated() if torch.cuda.is_available() else 0
try:
# 执行推理
outputs = self.llm.generate(inputs, sampling_params)
# 计算指标
end_time = time.time()
inference_time = end_time - start_time
# 统计 token 数量
if isinstance(outputs, list):
total_tokens = sum(len(output.outputs[0].token_ids) for output in outputs)
else:
total_tokens = len(outputs.outputs[0].token_ids)
# 更新指标
self.metrics["requests_total"] += 1
self.metrics["requests_success"] += 1
self.metrics["total_tokens_generated"] += total_tokens
self.metrics["total_inference_time"] += inference_time
# 计算吞吐量
throughput = total_tokens / inference_time
self.metrics["throughput_history"].append(throughput)
# 记录系统资源
if torch.cuda.is_available():
gpu_memory = torch.cuda.memory_allocated()
self.metrics["gpu_memory_usage"].append(gpu_memory)
cpu_percent = psutil.cpu_percent()
self.metrics["cpu_usage"].append(cpu_percent)
# 日志记录
self.logger.info(
f"Request completed - "
f"Tokens: {total_tokens}, "
f"Time: {inference_time:.3f}s, "
f"Throughput: {throughput:.2f} tokens/s, "
f"GPU Memory: {gpu_memory / 1e9:.2f}GB"
)
return {
"success": True,
"inference_time": inference_time,
"total_tokens": total_tokens,
"throughput": throughput,
"outputs": outputs
}
except Exception as e:
self.metrics["requests_failed"] += 1
self.logger.error(f"Request failed: {str(e)}")
return {
"success": False,
"error": str(e)
}
def get_performance_summary(self) -> Dict[str, Any]:
"""获取性能摘要"""
if self.metrics["requests_total"] == 0:
return {"message": "No requests processed yet"}
avg_inference_time = self.metrics["total_inference_time"] / self.metrics["requests_success"]
avg_throughput = sum(self.metrics["throughput_history"]) / len(self.metrics["throughput_history"])
success_rate = self.metrics["requests_success"] / self.metrics["requests_total"]
return {
"total_requests": self.metrics["requests_total"],
"success_rate": success_rate,
"avg_inference_time": avg_inference_time,
"avg_throughput": avg_throughput,
"total_tokens_generated": self.metrics["total_tokens_generated"],
"avg_gpu_memory_gb": sum(self.metrics["gpu_memory_usage"]) / len(self.metrics["gpu_memory_usage"]) / 1e9 if self.metrics["gpu_memory_usage"] else 0,
"avg_cpu_usage": sum(self.metrics["cpu_usage"]) / len(self.metrics["cpu_usage"]) if self.metrics["cpu_usage"] else 0
}
# 使用示例
def setup_monitoring(llm):
"""设置监控"""
monitor = TRTLLMMonitor(llm)
# 定期报告性能
import threading
import time
def periodic_report():
while True:
time.sleep(60) # 每分钟报告一次
summary = monitor.get_performance_summary()
monitor.logger.info(f"Performance Summary: {summary}")
report_thread = threading.Thread(target=periodic_report, daemon=True)
report_thread.start()
return monitor
3. 故障排除实战
3.1 常见问题诊断
内存不足问题
def diagnose_memory_issues():
"""诊断内存问题"""
print("=== GPU 内存诊断 ===")
if not torch.cuda.is_available():
print("CUDA 不可用")
return
for i in range(torch.cuda.device_count()):
device = f"cuda:{i}"
# 获取内存信息
total_memory = torch.cuda.get_device_properties(i).total_memory
allocated_memory = torch.cuda.memory_allocated(i)
cached_memory = torch.cuda.memory_reserved(i)
free_memory = total_memory - cached_memory
print(f"GPU {i}:")
print(f" 总内存: {total_memory / 1e9:.2f} GB")
print(f" 已分配: {allocated_memory / 1e9:.2f} GB")
print(f" 已缓存: {cached_memory / 1e9:.2f} GB")
print(f" 可用内存: {free_memory / 1e9:.2f} GB")
print(f" 利用率: {(allocated_memory / total_memory) * 100:.1f}%")
# 内存碎片检查
try:
# 尝试分配大块内存
test_tensor = torch.zeros((1000, 1000, 1000), device=device)
del test_tensor
print(f" 内存碎片: 正常")
except torch.cuda.OutOfMemoryError:
print(f" 内存碎片: 严重,建议重启进程")
def memory_optimization_suggestions(model_size_gb: float, available_memory_gb: float):
"""内存优化建议"""
suggestions = []
if model_size_gb > available_memory_gb * 0.8:
suggestions.extend([
"启用权重流式传输 (weight_streaming=True)",
"使用量化减少模型大小",
"增加张量并行度分散内存负载"
])
if available_memory_gb < 16:
suggestions.extend([
"减少 max_batch_size",
"减少 max_seq_len",
"启用 KV 缓存压缩"
])
return suggestions
性能问题诊断
def diagnose_performance_issues(llm, test_inputs: List[str]):
"""性能问题诊断"""
print("=== 性能诊断 ===")
# 1. 基准测试
latencies = []
throughputs = []
for i, input_text in enumerate(test_inputs):
start_time = time.time()
outputs = llm.generate(
input_text,
sampling_params=SamplingParams(max_tokens=100)
)
end_time = time.time()
latency = end_time - start_time
if isinstance(outputs, list):
total_tokens = sum(len(output.outputs[0].token_ids) for output in outputs)
else:
total_tokens = len(outputs.outputs[0].token_ids)
throughput = total_tokens / latency
latencies.append(latency)
throughputs.append(throughput)
print(f"测试 {i+1}: 延迟={latency:.3f}s, 吞吐量={throughput:.2f} tokens/s")
# 2. 统计分析
avg_latency = sum(latencies) / len(latencies)
avg_throughput = sum(throughputs) / len(throughputs)
print(f"\n平均延迟: {avg_latency:.3f}s")
print(f"平均吞吐量: {avg_throughput:.2f} tokens/s")
# 3. 性能建议
suggestions = []
if avg_latency > 2.0:
suggestions.append("延迟过高,考虑启用 CUDA 图优化")
if avg_throughput < 50:
suggestions.append("吞吐量偏低,检查批次大小和并行配置")
if len(suggestions) > 0:
print("\n优化建议:")
for suggestion in suggestions:
print(f" - {suggestion}")
def profile_model_performance(llm, num_warmup: int = 5, num_iterations: int = 20):
"""模型性能分析"""
# 预热
warmup_input = "Hello, how are you today?"
for _ in range(num_warmup):
llm.generate(warmup_input, sampling_params=SamplingParams(max_tokens=10))
# 性能测试
test_inputs = [
"Explain the concept of artificial intelligence.",
"Write a short story about a robot.",
"What are the benefits of renewable energy?",
"Describe the process of photosynthesis."
]
results = {
"first_token_latency": [],
"total_latency": [],
"throughput": [],
"gpu_utilization": []
}
for input_text in test_inputs:
for _ in range(num_iterations):
# 记录 GPU 利用率
if torch.cuda.is_available():
torch.cuda.synchronize()
start_memory = torch.cuda.memory_allocated()
start_time = time.time()
# 流式生成以测量首 token 延迟
first_token_time = None
total_tokens = 0
for output in llm.generate(
input_text,
sampling_params=SamplingParams(max_tokens=50),
streaming=True
):
if first_token_time is None:
first_token_time = time.time()
total_tokens += 1
end_time = time.time()
# 计算指标
first_token_latency = first_token_time - start_time
total_latency = end_time - start_time
throughput = total_tokens / total_latency
results["first_token_latency"].append(first_token_latency)
results["total_latency"].append(total_latency)
results["throughput"].append(throughput)
if torch.cuda.is_available():
end_memory = torch.cuda.memory_allocated()
memory_usage = (end_memory - start_memory) / 1e9
results["gpu_utilization"].append(memory_usage)
# 统计结果
for metric, values in results.items():
if values:
avg_val = sum(values) / len(values)
p95_val = sorted(values)[int(len(values) * 0.95)]
print(f"{metric}: 平均={avg_val:.3f}, P95={p95_val:.3f}")
3.2 调试技巧
启用详细日志
import os
import logging
def enable_debug_logging():
"""启用调试日志"""
# TensorRT-LLM 日志级别
os.environ["TRTLLM_LOG_LEVEL"] = "DEBUG"
# CUDA 调试
os.environ["CUDA_LAUNCH_BLOCKING"] = "1"
# NCCL 调试(多 GPU)
os.environ["NCCL_DEBUG"] = "INFO"
# Python 日志配置
logging.basicConfig(
level=logging.DEBUG,
format='%(asctime)s - %(name)s - %(levelname)s - %(message)s',
handlers=[
logging.FileHandler('debug.log'),
logging.StreamHandler()
]
)
print("调试日志已启用")
def trace_model_execution(llm, input_text: str):
"""跟踪模型执行"""
# 启用 PyTorch 分析器
with torch.profiler.profile(
activities=[
torch.profiler.ProfilerActivity.CPU,
torch.profiler.ProfilerActivity.CUDA,
],
record_shapes=True,
profile_memory=True,
with_stack=True
) as prof:
outputs = llm.generate(
input_text,
sampling_params=SamplingParams(max_tokens=20)
)
# 保存分析结果
prof.export_chrome_trace("trace.json")
# 打印关键统计
print(prof.key_averages().table(sort_by="cuda_time_total", row_limit=10))
return outputs
4. 高级优化技巧
4.1 自定义算子优化
def register_custom_attention_kernel():
"""注册自定义注意力内核"""
# 这是一个示例,实际需要 C++/CUDA 实现
custom_kernel_config = {
"kernel_name": "optimized_attention",
"block_size": 256,
"num_warps": 8,
"enable_flash_attention": True,
"use_tensor_cores": True
}
# 注册到 TensorRT-LLM
# 实际实现需要通过插件系统
pass
def optimize_for_specific_hardware(gpu_arch: str):
"""针对特定硬件优化"""
optimizations = {
"A100": {
"use_tf32": True,
"enable_flash_attention_2": True,
"optimal_block_size": 128
},
"H100": {
"use_fp8": True,
"enable_transformer_engine": True,
"optimal_block_size": 256
},
"V100": {
"use_mixed_precision": True,
"enable_gradient_checkpointing": True,
"optimal_block_size": 64
}
}
return optimizations.get(gpu_arch, optimizations["V100"])
4.2 动态批处理优化
class DynamicBatcher:
"""动态批处理器"""
def __init__(self, llm, max_batch_size: int = 32, max_wait_time: float = 0.1):
self.llm = llm
self.max_batch_size = max_batch_size
self.max_wait_time = max_wait_time
self.pending_requests = []
self.request_lock = threading.Lock()
async def add_request(self, input_text: str, sampling_params: SamplingParams):
"""添加请求到批处理队列"""
future = asyncio.Future()
with self.request_lock:
self.pending_requests.append({
"input": input_text,
"sampling_params": sampling_params,
"future": future,
"timestamp": time.time()
})
return await future
async def process_batches(self):
"""处理批次的后台任务"""
while True:
batch_requests = []
# 收集批次请求
with self.request_lock:
current_time = time.time()
# 按时间或大小触发批处理
if self.pending_requests:
oldest_request_time = self.pending_requests[0]["timestamp"]
time_elapsed = current_time - oldest_request_time
if (len(self.pending_requests) >= self.max_batch_size or
time_elapsed >= self.max_wait_time):
batch_requests = self.pending_requests[:self.max_batch_size]
self.pending_requests = self.pending_requests[self.max_batch_size:]
if batch_requests:
await self._process_batch(batch_requests)
else:
await asyncio.sleep(0.01) # 短暂休眠
async def _process_batch(self, batch_requests):
"""处理单个批次"""
try:
# 准备批次输入
inputs = [req["input"] for req in batch_requests]
sampling_params = [req["sampling_params"] for req in batch_requests]
# 执行批次推理
outputs = self.llm.generate(inputs, sampling_params)
# 分发结果
for i, request in enumerate(batch_requests):
request["future"].set_result(outputs[i])
except Exception as e:
# 处理错误
for request in batch_requests:
request["future"].set_exception(e)
# 使用示例
async def main():
llm = LLM(model="meta-llama/Llama-2-7b-hf")
batcher = DynamicBatcher(llm)
# 启动批处理任务
asyncio.create_task(batcher.process_batches())
# 并发请求
tasks = []
for i in range(10):
task = batcher.add_request(
f"Question {i}: What is AI?",
SamplingParams(max_tokens=50)
)
tasks.append(task)
results = await asyncio.gather(*tasks)
for i, result in enumerate(results):
print(f"Response {i}: {result}")
5. 生产环境最佳实践总结
5.1 配置检查清单
def production_readiness_check(llm_config: dict) -> dict:
"""生产就绪性检查"""
checks = {
"memory_optimization": False,
"error_handling": False,
"monitoring": False,
"security": False,
"scalability": False,
"performance": False,
"reliability": False
}
recommendations = []
# 内存优化检查
if llm_config.get("kv_cache_config", {}).get("enable_block_reuse", False):
checks["memory_optimization"] = True
else:
recommendations.append("启用 KV 缓存块重用")
# 错误处理检查
if llm_config.get("error_handling", {}).get("retry_config"):
checks["error_handling"] = True
else:
recommendations.append("配置重试机制")
# 监控检查
if llm_config.get("monitoring", {}).get("enabled", False):
checks["monitoring"] = True
else:
recommendations.append("启用性能监控")
# 安全检查
if llm_config.get("security", {}).get("input_validation", False):
checks["security"] = True
else:
recommendations.append("添加输入验证")
# 可扩展性检查
if llm_config.get("parallel_config", {}).get("tensor_parallel_size", 1) > 1:
checks["scalability"] = True
else:
recommendations.append("考虑并行配置")
# 性能检查
if llm_config.get("optimization", {}).get("enable_cuda_graph", False):
checks["performance"] = True
else:
recommendations.append("启用 CUDA 图优化")
# 可靠性检查
if llm_config.get("reliability", {}).get("health_check_enabled", False):
checks["reliability"] = True
else:
recommendations.append("配置健康检查")
return {
"checks": checks,
"recommendations": recommendations,
"ready": all(checks.values()),
"score": sum(checks.values()) / len(checks) * 100
}
# 生产配置模板
PRODUCTION_CONFIG_TEMPLATE = {
"model_config": {
"max_batch_size": 16,
"max_seq_len": 4096,
"max_input_len": 2048,
"strongly_typed": True,
"use_refit": True,
"weight_streaming": False
},
"kv_cache_config": {
"free_gpu_memory_fraction": 0.85,
"enable_block_reuse": True,
"max_tokens_in_paged_kv_cache": None
},
"quantization_config": {
"quant_algo": "FP8",
"kv_cache_quant_algo": "INT8",
"group_size": 128,
"calib_size": 512
},
"parallel_config": {
"tensor_parallel_size": 2,
"pipeline_parallel_size": 1,
"moe_expert_parallel_size": None
},
"optimization": {
"enable_cuda_graph": True,
"use_fused_attention": True,
"enable_kv_cache_reuse": True,
"max_beam_width": 4
},
"monitoring": {
"enabled": True,
"metrics_interval": 60,
"log_level": "INFO",
"export_prometheus": True,
"trace_requests": False
},
"error_handling": {
"retry_config": {
"max_retries": 3,
"backoff_factor": 2.0,
"retry_exceptions": ["TimeoutError", "CudaError"]
},
"timeout_seconds": 30,
"circuit_breaker": {
"failure_threshold": 5,
"recovery_timeout": 60
}
},
"security": {
"input_validation": True,
"max_input_length": 8192,
"content_filtering": True,
"rate_limiting": {
"requests_per_minute": 100,
"burst_size": 10
},
"authentication": {
"enabled": True,
"token_validation": True
}
},
"reliability": {
"health_check_enabled": True,
"health_check_interval": 30,
"graceful_shutdown_timeout": 60,
"auto_recovery": True
}
}
5.2 高级性能调优技巧
5.2.1 内存池优化
class AdvancedMemoryManager:
"""高级内存管理器"""
def __init__(self, gpu_memory_gb: float):
self.total_memory = gpu_memory_gb * 1024**3
self.memory_pools = {}
self.allocation_strategy = "best_fit"
def optimize_memory_layout(self, model_config: dict):
"""优化内存布局"""
# 计算各组件内存需求
model_memory = self._estimate_model_memory(model_config)
kv_cache_memory = self._estimate_kv_cache_memory(model_config)
activation_memory = self._estimate_activation_memory(model_config)
# 内存分配策略
memory_allocation = {
"model_weights": model_memory,
"kv_cache": kv_cache_memory,
"activations": activation_memory,
"workspace": self.total_memory * 0.1, # 10% 工作空间
"reserved": self.total_memory * 0.05 # 5% 预留
}
total_required = sum(memory_allocation.values())
if total_required > self.total_memory:
# 内存不足,启用优化策略
return self._apply_memory_optimization(memory_allocation)
return memory_allocation
def _apply_memory_optimization(self, allocation: dict):
"""应用内存优化策略"""
optimizations = []
# 1. 启用权重流式传输
if allocation["model_weights"] > self.total_memory * 0.6:
optimizations.append("weight_streaming")
allocation["model_weights"] *= 0.3 # 减少70%内存占用
# 2. 压缩KV缓存
if allocation["kv_cache"] > self.total_memory * 0.4:
optimizations.append("kv_cache_compression")
allocation["kv_cache"] *= 0.5 # 减少50%内存占用
# 3. 激活检查点
if allocation["activations"] > self.total_memory * 0.2:
optimizations.append("activation_checkpointing")
allocation["activations"] *= 0.3 # 减少70%内存占用
return {
"allocation": allocation,
"optimizations": optimizations,
"memory_saved": self._calculate_memory_saved(optimizations)
}
#### 5.2.2 动态批处理优化
```python
class DynamicBatchOptimizer:
"""动态批处理优化器"""
def __init__(self, max_batch_size: int = 32, max_wait_time: float = 0.1):
self.max_batch_size = max_batch_size
self.max_wait_time = max_wait_time
self.request_queue = asyncio.Queue()
self.batch_stats = {
"total_batches": 0,
"avg_batch_size": 0,
"avg_wait_time": 0,
"throughput_history": []
}
async def optimize_batching(self, llm):
"""优化批处理策略"""
while True:
batch = await self._collect_batch()
if not batch:
await asyncio.sleep(0.01)
continue
# 动态调整批次大小
optimal_batch_size = self._calculate_optimal_batch_size(batch)
if len(batch) > optimal_batch_size:
# 分割批次
batches = self._split_batch(batch, optimal_batch_size)
for sub_batch in batches:
await self._process_batch(sub_batch, llm)
else:
await self._process_batch(batch, llm)
def _calculate_optimal_batch_size(self, batch: list) -> int:
"""计算最优批次大小"""
# 基于序列长度分布计算
seq_lengths = [len(req.prompt_token_ids) for req in batch]
avg_seq_len = sum(seq_lengths) / len(seq_lengths)
max_seq_len = max(seq_lengths)
# 内存约束下的最大批次大小
memory_constrained_size = self._estimate_max_batch_size(max_seq_len)
# 延迟约束下的最优批次大小
latency_optimal_size = self._estimate_latency_optimal_size(avg_seq_len)
return min(memory_constrained_size, latency_optimal_size, self.max_batch_size)
async def _collect_batch(self) -> list:
"""收集批次请求"""
batch = []
start_time = time.time()
# 收集第一个请求
try:
first_request = await asyncio.wait_for(
self.request_queue.get(),
timeout=self.max_wait_time
)
batch.append(first_request)
except asyncio.TimeoutError:
return batch
# 收集更多请求直到达到限制
while (len(batch) < self.max_batch_size and
time.time() - start_time < self.max_wait_time):
try:
request = await asyncio.wait_for(
self.request_queue.get(),
timeout=0.01
)
batch.append(request)
except asyncio.TimeoutError:
break
return batch
#### 5.2.3 智能缓存策略
```python
class IntelligentCacheManager:
"""智能缓存管理器"""
def __init__(self, cache_size_gb: float = 8.0):
self.cache_size = cache_size_gb * 1024**3
self.semantic_cache = {}
self.lru_cache = {}
self.cache_stats = {
"hits": 0,
"misses": 0,
"evictions": 0
}
def get_cached_result(self, prompt: str, sampling_params: dict) -> Optional[str]:
"""获取缓存结果"""
# 1. 精确匹配缓存
exact_key = self._generate_exact_key(prompt, sampling_params)
if exact_key in self.lru_cache:
self.cache_stats["hits"] += 1
return self.lru_cache[exact_key]
# 2. 语义相似性缓存
semantic_result = self._semantic_cache_lookup(prompt, sampling_params)
if semantic_result:
self.cache_stats["hits"] += 1
return semantic_result
self.cache_stats["misses"] += 1
return None
def cache_result(self, prompt: str, sampling_params: dict, result: str):
"""缓存结果"""
exact_key = self._generate_exact_key(prompt, sampling_params)
# 检查缓存空间
if self._get_cache_size() > self.cache_size * 0.9:
self._evict_lru_entries()
# 存储到精确匹配缓存
self.lru_cache[exact_key] = result
# 存储到语义缓存
self._store_semantic_cache(prompt, sampling_params, result)
def _semantic_cache_lookup(self, prompt: str, sampling_params: dict) -> Optional[str]:
"""语义缓存查找"""
# 计算提示的语义嵌入
prompt_embedding = self._compute_embedding(prompt)
# 查找相似的缓存条目
for cached_prompt, cached_data in self.semantic_cache.items():
similarity = self._compute_similarity(
prompt_embedding,
cached_data["embedding"]
)
# 相似度阈值和参数匹配
if (similarity > 0.95 and
self._params_compatible(sampling_params, cached_data["params"])):
return cached_data["result"]
return None
def _params_compatible(self, params1: dict, params2: dict) -> bool:
"""检查参数兼容性"""
# 关键参数必须完全匹配
critical_params = ["max_tokens", "temperature", "top_p", "top_k"]
for param in critical_params:
if abs(params1.get(param, 0) - params2.get(param, 0)) > 1e-6:
return False
return True
5.2 关键性能指标 (KPI)
class ProductionKPIs:
"""生产环境关键性能指标"""
TARGET_METRICS = {
"latency_p95_ms": 2000, # P95 延迟 < 2秒
"throughput_tokens_per_sec": 100, # 吞吐量 > 100 tokens/s
"availability_percent": 99.9, # 可用性 > 99.9%
"error_rate_percent": 0.1, # 错误率 < 0.1%
"gpu_utilization_percent": 80, # GPU 利用率 > 80%
"memory_utilization_percent": 85 # 内存利用率 < 85%
}
@staticmethod
def evaluate_performance(metrics: dict) -> dict:
"""评估性能是否达标"""
results = {}
for metric, target in ProductionKPIs.TARGET_METRICS.items():
actual = metrics.get(metric, 0)
if metric in ["latency_p95_ms", "error_rate_percent", "memory_utilization_percent"]:
# 越小越好的指标
passed = actual <= target
else:
# 越大越好的指标
passed = actual >= target
results[metric] = {
"target": target,
"actual": actual,
"passed": passed,
"deviation": ((actual - target) / target) * 100
}
overall_passed = all(result["passed"] for result in results.values())
return {
"overall_passed": overall_passed,
"metrics": results
}
这份实战经验文档涵盖了 TensorRT-LLM 在生产环境中的性能优化、部署实践、故障排除和高级优化技巧,为实际项目提供了详细的技术指导和最佳实践建议。