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

• 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.

Support Node.js >= 8.0.0

$ npm install agentkeepalive --save

• 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.

consthttp=require('http');constHttpAgent=require('agentkeepalive').HttpAgent;constkeepaliveAgent=newHttpAgent({maxSockets: 100,maxFreeSockets: 10,timeout: 60000,// active socket keepalive for 60 secondsfreeSocketTimeout: 30000,// free socket keepalive for 30 seconds});constoptions={host: 'cnodejs.org',port: 80,path: '/',method: 'GET',agent: keepaliveAgent,};constreq=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);

counters have change or not after last checkpoint.

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: {}}

consthttps=require('https');constHttpsAgent=require('agentkeepalive').HttpsAgent;constkeepaliveAgent=newHttpsAgent();// https://www.google.com/search?q=nodejs&sugexp=chrome,mod=12&sourceid=chrome&ie=UTF-8constoptions={host: 'www.google.com',port: 443,path: '/search?q=nodejs&sugexp=chrome,mod=12&sourceid=chrome&ie=UTF-8',method: 'GET',agent: keepaliveAgent,};constreq=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);

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.

consthttp=require('http');constHttpAgent=require('agentkeepalive').HttpAgent;constagent=newHttpAgent();constreq=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.

run the benchmark:

cd benchmark sh start.sh

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

[email protected]

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

Keep alive agent (30 seconds):

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

Normal agent:

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

MIT

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.