agentkeepalive

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[npm-image]: https://img.shields.io/npm/v/agentkeepalive.svg?style=flat
[npm-url]: https://npmjs.org/package/agentkeepalive
[snyk-image]: https://snyk.io/test/npm/agentkeepalive/badge.svg?style=flat-square
[snyk-url]: https://snyk.io/test/npm/agentkeepalive
[download-image]: https://img.shields.io/npm/dm/agentkeepalive.svg?style=flat-square
[download-url]: https://npmjs.org/package/agentkeepalive

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

``bash
$ 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.
The default server-side timeout is 5000 milliseconds, to avoid ECONNRESET exceptions, we set the default value to 4000 milliseconds.
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 so long as that value is greater than or equal to 8 seconds, otherwise the default is 8 seconds.
* 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

`js
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);

`

$3

counters have change or not after last checkpoint.

$3

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

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

$3

`js
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);
`

$3

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.

`js
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:

`bash
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):

`js
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:

`js
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:

`bash
[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

Contributors

|
fengmk2
|
dead-horse
|
AndrewLeedham
|
ngot
|
wrynearson
|
aaronArinder
|
| :---: | :---: | :---: | :---: | :---: | :---: |
|
alexpenev-s
|
blemoine
|
bdehamer
|
DylanPiercey
|
cixel
|
HerringtonDarkholme
|
|
denghongcai
|
kibertoad
|
pangorgo
|
mattiash
|
nabeelbukhari
|
pmalouin
|

SimenB
|
vinaybedre
|
starkwang
|
killagu
|
tony-gutierrez
|
whxaxes


This project follows the git-contributor spec, auto updated at Sat Aug 05 2023 02:36:31 GMT+0800`.