Support keepalive http agent.

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

$ 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

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

Contributors

fengmk2	dead-horse	AndrewLeedham	ngot	wrynearson	aaronArinder
alexpenev-s	blemoine	bdehamer	DylanPiercey	cixel	HerringtonDarkholme
denghongcai	kibertoad	pangorgo	mattiash	pmalouin	SimenB
vinaybedre	starkwang	killagu	tony-gutierrez	whxaxes

This project follows the git-contributor spec, auto updated at Mon Mar 06 2023 12:29:54 GMT+0800.