nginx 504后其他请求均失败

Question

windows当一个请求504后其他请求均502，错误日志：
connect() failed (10061: No connection could be made because the target machine actively refused it) while connecting to upstream, client: 127.0.0.1, server: _, request: "GET /websocket/ HTTP/1.1", upstream: "https://127.0.0.1:8086/websocket/", host: "127.0.0.1:8081"

upstream timed out (10060: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond) while SSL handshaking to upstream, client: 127.0.0.1, server: _, request: "POST /routerAndPhoneInfo/ HTTP/1.1", upstream: "https://127.0.0.1:8083/routerAndPhoneInfo/", host: "127.0.0.1:8081", referrer: "https://127.0.0.1:8081/"

no live upstreams while connecting to upstream, client: 127.0.0.1, server: _, request: "POST /routerAndPhoneInfo/ HTTP/1.1", upstream: "https://backs/routerAndPhoneInfo/", host: "127.0.0.1:8081", referrer: "https://127.0.0.1:8081/"

def init_server_socket():

# 请求服务端登录
global socket_server
try:
    socket_obj = SocketHandle(server_addr=configPara.SERVER_ADDR, server_port=configPara.ELF_PORT)
    client_conn_socket = socket_obj.socket_connect()
    socket_server = client_conn_socket
    sock_login()
except Exception as e:
    msg = err_record_log(self=None, e=e)
    log_err.error(msg)

def socket_send(data=None, sock=None):

global socket_server
global g_token
data['timestamp'] = int(time.time())
try:
    if not socket_server:
        init_server_socket()
    data['token'] = g_token
    print(f'send_data:{data}')
    data = json.dumps(data).encode()
    data_len = struct.pack('i', len(data))
    socket_server.sendall(data_len)
    socket_server.sendall(data)
except Exception as err:
    msg = err_record_log(self=None, e=err)
    log_err.error(msg)
    socket_server.close()
    socket_server = None
    g_token = None

Answer 1

你是用代码模拟的、还是后面服务真挂了？

真挂了这是正常的，因为 504 就是后面服务没在规定时间内返回响应，I/O 阻塞住了，大概率是死掉了；而再进来的请求很可能后面服务已经不能正常处理了（连接收报文都无法做到），从 TCP 包上看就是奇怪的结果，nginx 不认识，所以就 502 了。