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agentkeepalive

4.1.0 • Public • Published

agentkeepalive

NPM version build status Appveyor status Test coverage David deps Known Vulnerabilities npm download

The enhancement features keep alive http.Agent. Support http and https.

What's different from original http.Agent?

  • keepAlive=true by default
  • Disable Nagle's algorithm: socket.setNoDelay(true)
  • Add free socket timeout: avoid long time inactivity socket leak in the free-sockets queue.
  • Add active socket timeout: avoid long time inactivity socket leak in the active-sockets queue.
  • TTL for active socket.

Node.js version required

Support Node.js >= 8.0.0

Install

$ npm install agentkeepalive --save

new Agent([options])

  • options {Object} Set of configurable options to set on the agent. Can have the following fields:
    • keepAlive {Boolean} Keep sockets around in a pool to be used by other requests in the future. Default = true.
    • keepAliveMsecs {Number} When using the keepAlive option, specifies the initial delay for TCP Keep-Alive packets. Ignored when the keepAlive option is false or undefined. Defaults to 1000. Default = 1000. Only relevant if keepAlive is set to true.
    • freeSocketTimeout: {Number} Sets the free socket to timeout after freeSocketTimeout milliseconds of inactivity on the free socket. Default is 15000. Only relevant if keepAlive is set to true.
    • timeout: {Number} Sets the working socket to timeout after timeout milliseconds of inactivity on the working socket. Default is freeSocketTimeout * 2.
    • maxSockets {Number} Maximum number of sockets to allow per host. Default = Infinity.
    • maxFreeSockets {Number} Maximum number of sockets (per host) to leave open in a free state. Only relevant if keepAlive is set to true. Default = 256.
    • socketActiveTTL {Number} Sets the socket active time to live, even if it's in use. If not set, the behaviour keeps the same (the socket will be released only when free) Default = null.

Usage

const http = require('http');
const Agent = require('agentkeepalive');
 
const keepaliveAgent = new Agent({
  maxSockets: 100,
  maxFreeSockets: 10,
  timeout: 60000, // active socket keepalive for 60 seconds
  freeSocketTimeout: 30000, // free socket keepalive for 30 seconds
});
 
const options = {
  host: 'cnodejs.org',
  port: 80,
  path: '/',
  method: 'GET',
  agent: keepaliveAgent,
};
 
const req = http.request(options, res => {
  console.log('STATUS: ' + res.statusCode);
  console.log('HEADERS: ' + JSON.stringify(res.headers));
  res.setEncoding('utf8');
  res.on('data', function (chunk) {
    console.log('BODY: ' + chunk);
  });
});
req.on('error', e => {
  console.log('problem with request: ' + e.message);
});
req.end();
 
setTimeout(() => {
  if (keepaliveAgent.statusChanged) {
    console.log('[%s] agent status changed: %j', Date(), keepaliveAgent.getCurrentStatus());
  }
}, 2000);
 

getter agent.statusChanged

counters have change or not after last checkpoint.

agent.getCurrentStatus()

agent.getCurrentStatus() will return a object to show the status of this agent:

{
  createSocketCount: 10,
  closeSocketCount: 5,
  timeoutSocketCount: 0,
  requestCount: 5,
  freeSockets: { 'localhost:57479:': 3 },
  sockets: { 'localhost:57479:': 5 },
  requests: {}
}

Support https

const https = require('https');
const HttpsAgent = require('agentkeepalive').HttpsAgent;
 
const keepaliveAgent = new HttpsAgent();
// https://www.google.com/search?q=nodejs&sugexp=chrome,mod=12&sourceid=chrome&ie=UTF-8
const options = {
  host: 'www.google.com',
  port: 443,
  path: '/search?q=nodejs&sugexp=chrome,mod=12&sourceid=chrome&ie=UTF-8',
  method: 'GET',
  agent: keepaliveAgent,
};
 
const req = https.request(options, res => {
  console.log('STATUS: ' + res.statusCode);
  console.log('HEADERS: ' + JSON.stringify(res.headers));
  res.setEncoding('utf8');
  res.on('data', chunk => {
    console.log('BODY: ' + chunk);
  });
});
 
req.on('error', e => {
  console.log('problem with request: ' + e.message);
});
req.end();
 
setTimeout(() => {
  console.log('agent status: %j', keepaliveAgent.getCurrentStatus());
}, 2000);

Support req.reusedSocket

This agent implements the req.reusedSocket to determine whether a request is send through a reused socket.

When server closes connection at unfortunate time (keep-alive race), the http client will throw a ECONNRESET error. Under this circumstance, req.reusedSocket is useful when we want to retry the request automatically.

const http = require('http');
const Agent = require('agentkeepalive');
const agent = new Agent();
 
const req = http
  .get('http://localhost:3000', { agent }, (res) => {
    // ...
  })
  .on('error', (err) => {
    if (req.reusedSocket && err.code === 'ECONNRESET') {
      // retry the request or anything else...
    }
  })

This behavior is consistent with Node.js core. But through agentkeepalive, you can use this feature in older Node.js version.

Benchmark

run the benchmark:

cd benchmark
sh start.sh

Intel(R) Core(TM)2 Duo CPU P8600 @ 2.40GHz

node@v0.8.9

50 maxSockets, 60 concurrent, 1000 requests per concurrent, 5ms delay

Keep alive agent (30 seconds):

Transactions:          60000 hits
Availability:         100.00 %
Elapsed time:          29.70 secs
Data transferred:        14.88 MB
Response time:            0.03 secs
Transaction rate:      2020.20 trans/sec
Throughput:           0.50 MB/sec
Concurrency:           59.84
Successful transactions:       60000
Failed transactions:             0
Longest transaction:          0.15
Shortest transaction:         0.01

Normal agent:

Transactions:          60000 hits
Availability:         100.00 %
Elapsed time:          46.53 secs
Data transferred:        14.88 MB
Response time:            0.05 secs
Transaction rate:      1289.49 trans/sec
Throughput:           0.32 MB/sec
Concurrency:           59.81
Successful transactions:       60000
Failed transactions:             0
Longest transaction:          0.45
Shortest transaction:         0.00

Socket created:

[proxy.js:120000] keepalive, 50 created, 60000 requestFinished, 1200 req/socket, 0 requests, 0 sockets, 0 unusedSockets, 50 timeout
{" <10ms":662," <15ms":17825," <20ms":20552," <30ms":17646," <40ms":2315," <50ms":567," <100ms":377," <150ms":56," <200ms":0," >=200ms+":0}
----------------------------------------------------------------
[proxy.js:120000] normal   , 53866 created, 84260 requestFinished, 1.56 req/socket, 0 requests, 0 sockets
{" <10ms":75," <15ms":1112," <20ms":10947," <30ms":32130," <40ms":8228," <50ms":3002," <100ms":4274," <150ms":181," <200ms":18," >=200ms+":33}

License

MIT

install

npm i agentkeepalive

Downloadsweekly downloads

2,345,579

version

4.1.0

license

MIT

homepage

github.com

repository

Gitgithub

last publish

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