Node.JS，服务器在请求中间关闭 Keep-Alive 连接

Question

我有 Node.js HTTP 服务器，如果空闲 10 秒就会关闭传入连接，客户端使用 Keep-Alive 连接池来请求此服务器。当我开始以 10 秒的间隔发送请求时，我定期收到错误消息 ECONNRESET，我认为是因为连接在 HTTP 请求中间关闭。除了简单的重新发送请求，还有什么优雅的解决方案吗？

server.js

var server = require('http').createServer(function(req, res) {
  console.log(new Date(), "Request ", req.method);
  res.end("Nice");
});

server.timeout = 10000;

server.on("connection", function(socket) {
  console.log("New connection");
  socket._created = new Date().getTime();
  socket.on("close", function() {
    var now = new Date().getTime();
    console.log(new Date(), "Socket closed, TTL", (now - socket._created)/1000);
  });
});
server.listen(3000);

client.js

var http = require("http");

var agent = new http.Agent({
  keepAlive: true
});

var reqSent = 0;
var NEED_REQS = 10;
var TIMEOUT = 10000;

function _req() {
  var start = new Date().getTime();
  var req = http.get({
    host: "localhost",
    port: 3000,
    agent: agent
  }, function(res) {
    reqSent++;
    var now = new Date().getTime();
    console.log("Sent:", reqSent, (now - start)/1000);

    if(reqSent >= NEED_REQS) {
      agent.destroy();
      return;
    }
    res.setEncoding('utf8');
    res.on('data', function (chunk) {
    });

    setTimeout(function() {
      _req();
    }, TIMEOUT);
  });
  req.on("error", function(err) {
    console.error(err);
  });
}

_req();

运行 client.js

$ node client.js
Sent: 1 0.028
Sent: 2 0.008
Sent: 3 0.002
{ [Error: read ECONNRESET] code: 'ECONNRESET', errno: 'ECONNRESET', syscall: 'read' }

Answer 1

我认为只有一种解决方案 - 如果获得 ECONNRESET 则重新发送请求，我找到了很好的包含这种逻辑的库 https://github.com/FGRibreau/node-request-retry

Answer 2

我确实重现了您每 5 秒发送一次请求的问题。 nodejs默认的keepAlive超时时间是5秒，https://nodejs.org/api/http.html#http_server_keepalivetimeout

这个针对 nodejs 的 github 问题很好地解释了行为，https://github.com/nodejs/node/issues/20256 解决方法是将客户端的 keepAlive 超时设置为小于服务器端超时的值，但我在 nodejs 中看不到这样的选项，https://nodejs.org/api/http.html#http_new_agent_options

Node.JS，服务器在请求中间关闭 Keep-Alive 连接

Node.JS, Server close Keep-Alive connection in middle of request

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keep-alive