问题
I'm running a node.js server A which uses superagent to issue HTTP requests to another server B.
I investigated the request on server B and saw the the header connection
being close
and the httpVersion being 1.1
:
var http = require('http');
var request = require('superagent');
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/plain'});
res.write('req.httpVersion seen on server:' + req.httpVersion);
res.write('\nreq.headers.connection seen on server:' + req.headers.connection);
res.end();
}).listen(1337, '0.0.0.0');
request
.get('localhost:1337/helloword')
.end(function (err, res) {
console.log(res.text);
});
This leads to:
req.httpVersion seen on server:1.1
req.headers.connection seen on server:close
However if I access the same server from a browser I get:
req.httpVersion seen on server:1.1
req.headers.connection seen on server:keep-alive
From http://tools.ietf.org/html/rfc2616#page-172 I learned that keep-alive
is the default for HTTP 1.1 unless declared otherwise by using Connection: close
.
So, my questions are:
- Why does Superagent / Node.js explicitly set the request to not use keep-alive / persistent connections?
- How can I force Superagent / Node.js to use keep-alive connections?
- How can I further influence the exact behaviour (how many connections to keep open, timeouts etc.)?
回答1:
It doesn't seem to be documented but you can pass an http agent to superagent with the function agent
.
So you could create a keep-alive agent with this module: https://www.npmjs.org/package/agentkeepalive and pass it to superagent.
Something like this:
util = require('util');
util.debuglog = require('debuglog');
var http = require('http');
var request = require('superagent');
var Agent = require('agentkeepalive');
var keepaliveAgent = new Agent({
maxSockets: 100,
maxFreeSockets: 10,
timeout: 60000,
keepAliveTimeout: 30000 // free socket keepalive for 30 seconds
});
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/plain'});
res.write('req.httpVersion seen on server:' + req.httpVersion);
res.write('\nreq.headers.connection seen on server:' + req.headers.connection);
res.end();
}).listen(1337, '0.0.0.0');
request
.get('localhost:1337/helloword')
.agent(keepaliveAgent)
.end(function (err, res) {
console.log(res.text);
});
回答2:
Browers can reuse socket handle, so it send the header Connection: keep-alive
to server.
If you want to keep alive connection you can send that header like this:
request
.get('localhost:1337/helloword')
.set('Connection', 'keep-alive')
.end(function (err, res) {
console.log(res.text);
});
回答3:
For superagent .timeout(5000) is also available to use.
await superagent.get(`${anyurl}`, { rejectUnauthorized: false })
.set({ "Accept": "application/json", "Content-Type": "application/json", })
.auth(username, password, { "type": "auto" })
.timeout(1000)
来源:https://stackoverflow.com/questions/20743546/keep-alive-connection-with-superagent