面试题：网络编程之非阻塞Socket监控指标及实现

Question

对于非阻塞Socket编程，列举出至少5个重要的监控指标，如吞吐量、连接数等。并阐述如何在代码层面实现对这些指标的监控和数据采集，假设使用Python语言。

Answer 1

重要监控指标

1. 吞吐量：单位时间内传输的数据量，可细分为发送和接收吞吐量。
2. 连接数：当前建立的Socket连接数量。
3. 延迟：从发送数据到接收到响应的时间间隔。
4. 带宽利用率：实际使用的带宽占总可用带宽的比例。
5. 错误率：例如连接错误、数据传输错误等出现的频率。
6. 资源利用率：包括CPU、内存等资源在Socket操作上的使用情况。

代码层面实现监控和数据采集（Python示例）

1. 吞吐量监控

import time

total_sent = 0
total_received = 0
start_time = time.time()

def monitor_throughput(sock):
    global total_sent, total_received, start_time
    data = sock.recv(1024)
    total_received += len(data)
    sent = sock.send(b"some data")
    total_sent += sent
    elapsed_time = time.time() - start_time
    if elapsed_time >= 1:
        send_throughput = total_sent / elapsed_time
        recv_throughput = total_received / elapsed_time
        print(f"Send Throughput: {send_throughput} bytes/sec, Recv Throughput: {recv_throughput} bytes/sec")
        total_sent = 0
        total_received = 0
        start_time = time.time()

2. 连接数监控

active_connections = set()

def monitor_connections(sock):
    connection = sock.accept()[0]
    active_connections.add(connection)
    print(f"Current Connections: {len(active_connections)}")
    # 连接关闭时
    def close_connection(conn):
        if conn in active_connections:
            active_connections.remove(conn)
            print(f"Current Connections: {len(active_connections)}")

3. 延迟监控

import time

def monitor_latency(sock):
    start = time.time()
    sock.send(b"ping")
    response = sock.recv(1024)
    end = time.time()
    latency = (end - start) * 1000
    print(f"Latency: {latency} ms")

4. 带宽利用率监控

import psutil

def monitor_bandwidth_utilization():
    net_io = psutil.net_io_counters()
    sent = net_io.bytes_sent
    recv = net_io.bytes_recv
    # 假设总带宽为100Mbps，转换为字节/秒
    total_bandwidth = 100 * 1024 * 1024 / 8
    current_bandwidth = (sent + recv) / 1  # 每秒数据量
    utilization = current_bandwidth / total_bandwidth * 100
    print(f"Bandwidth Utilization: {utilization}%")

5. 错误率监控

error_count = 0
total_operations = 0

def monitor_error_rate():
    global error_count, total_operations
    try:
        # Socket操作代码
        pass
    except Exception as e:
        error_count += 1
    total_operations += 1
    error_rate = error_count / total_operations * 100 if total_operations > 0 else 0
    print(f"Error Rate: {error_rate}%")

6. 资源利用率监控

import psutil

def monitor_resource_utilization():
    cpu_percent = psutil.cpu_percent()
    memory_info = psutil.virtual_memory()
    memory_percent = memory_info.percent
    print(f"CPU Utilization: {cpu_percent}%, Memory Utilization: {memory_percent}%")