http: add maxTotalSockets to agent class

doc/api/http.md

@@ -300,6 +300,16 @@ added: v0.3.6
 By default set to `Infinity`. Determines how many concurrent sockets the agent
 can have open per origin. Origin is the returned value of [`agent.getName()`][].
 
+### `agent.maxTotalSockets`
+<!-- YAML
+added: REPLACEME
+-->
+
+* {number}
+
+By default set to `Infinity`. Determines how many concurrent sockets the agent
+can have open.
+
 ### `agent.requests`
 <!-- YAML
 added: v0.5.9

lib/_http_agent.js

@@ -36,9 +36,11 @@ const {
  codes: {
  ERR_INVALID_ARG_TYPE,
  ERR_INVALID_OPT_VALUE,
+ ERR_OUT_OF_RANGE,
  },
 } = require('internal/errors');
 const { once } = require('internal/util');
+const { validateNumber } = require('internal/validators');
 
 const kOnKeylog = Symbol('onkeylog');
 // New Agent code.
@@ -88,11 +90,22 @@ function Agent(options) {
  this.maxSockets = this.options.maxSockets || Agent.defaultMaxSockets;
  this.maxFreeSockets = this.options.maxFreeSockets || 256;
  this.scheduling = this.options.scheduling || 'fifo';
+ this.maxTotalSockets = this.options.maxTotalSockets;
+ this.totalSocketCount = 0;
 
  if (this.scheduling !== 'fifo' && this.scheduling !== 'lifo') {
  throw new ERR_INVALID_OPT_VALUE('scheduling', this.scheduling);
  }
 
+ if (this.maxTotalSockets !== undefined) {
+ validateNumber(this.maxTotalSockets, 'maxTotalSockets');
+ if (this.maxTotalSockets <= 0)
+ throw new ERR_OUT_OF_RANGE('maxTotalSockets', '> 0',
+ this.maxTotalSockets);
+ } else {
+ this.maxTotalSockets = Infinity;
+ }
+
  this.on('free', (socket, options) => {
  const name = this.getName(options);
  debug('agent.on(free)', name);
@@ -131,7 +144,8 @@ function Agent(options) {
  if (this.sockets[name])
  count += this.sockets[name].length;
 
- if (count > this.maxSockets ||
+ if (this.totalSocketCount > this.maxTotalSockets ||
+ count > this.maxSockets ||
  freeLen >= this.maxFreeSockets ||
  !this.keepSocketAlive(socket)) {
  socket.destroy();
@@ -246,7 +260,9 @@ Agent.prototype.addRequest = function addRequest(req, options, port/* legacy */,
  this.reuseSocket(socket, req);
  setRequestSocket(this, req, socket);
  this.sockets[name].push(socket);
- } else if (sockLen < this.maxSockets) {
+ this.totalSocketCount++;
+ } else if (sockLen < this.maxSockets &&
+ this.totalSocketCount < this.maxTotalSockets) {
  debug('call onSocket', sockLen, freeLen);
  // If we are under maxSockets create a new one.
  this.createSocket(req, options, (err, socket) => {
@@ -261,6 +277,10 @@ Agent.prototype.addRequest = function addRequest(req, options, port/* legacy */,
  if (!this.requests[name]) {
  this.requests[name] = [];
  }
+
+ // Used to create sockets for pending requests from different origin
+ req._options = options;
+
  this.requests[name].push(req);
  }
 };
@@ -286,7 +306,8 @@ Agent.prototype.createSocket = function createSocket(req, options, cb) {
  this.sockets[name] = [];
  }
  this.sockets[name].push(s);
- debug('sockets', name, this.sockets[name].length);
+ this.totalSocketCount++;
+ debug('sockets', name, this.sockets[name].length, this.totalSocketCount);
  installListeners(this, s, options);
  cb(null, s);
  });
@@ -392,13 +413,27 @@ Agent.prototype.removeSocket = function removeSocket(s, options) {
  // Don't leak
  if (sockets[name].length === 0)
  delete sockets[name];
+ this.totalSocketCount--;
  }
  }
  }
 
+ let req;
  if (this.requests[name] && this.requests[name].length) {
  debug('removeSocket, have a request, make a socket');
- const req = this.requests[name][0];
+ req = this.requests[name][0];
+ } else {
+ for (const prop in this.requests) {
+ debug('removeSocket, have a request with different origin,' +
+ ' make a socket');
+ req = this.requests[prop][0];
+ options = req._options;
+ break;
+ }
+ }
+
+ if (req && options) {
+ delete req._options;
  // If we have pending requests and a socket gets closed make a new one
  this.createSocket(req, options, (err, socket) => {
  if (err)
@@ -407,6 +442,7 @@ Agent.prototype.removeSocket = function removeSocket(s, options) {
  socket.emit('free');
  });
  }
+
 };
 
 Agent.prototype.keepSocketAlive = function keepSocketAlive(socket) {

test/parallel/test-http-agent-maxtotalsockets.js

@@ -0,0 +1,94 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const http = require('http');
+const Countdown = require('../common/countdown');
+
+assert.throws(() => new http.Agent({
+ maxTotalSockets: 'test',
+}), {
+ code: 'ERR_INVALID_ARG_TYPE',
+ name: 'TypeError',
+ message: 'The "maxTotalSockets" argument must be of type number. ' +
+ "Received type string ('test')",
+});
+
+assert.throws(() => new http.Agent({
+ maxTotalSockets: -1,
+}), {
+ code: 'ERR_OUT_OF_RANGE',
+ name: 'RangeError',
+ message: 'The value of "maxTotalSockets" is out of range. ' +
+ 'It must be > 0. Received -1',
+});
+
+const maxTotalSockets = 2;
+const maxSockets = 3;
+
+const agent = new http.Agent({
+ keepAlive: true,
+ keepAliveMsecs: 1000,
+ maxTotalSockets,
+ maxSockets,
+ maxFreeSockets: 3
+});
+
+const server = http.createServer(common.mustCall((req, res) => {
+ res.end('hello world');
+}, 6));
+const server2 = http.createServer(common.mustCall((req, res) => {
+ res.end('hello world');
+}, 6));
+
+server.keepAliveTimeout = 0;
+server2.keepAliveTimeout = 0;
+
+const countdown = new Countdown(12, () => {
+ assert.strictEqual(getRequestCount(), 0);
+ agent.destroy();
+ server.close();
+ server2.close();
+});
+
+function handler(s) {
+ for (let i = 0; i < 6; i++) {
+ http.get({
+ host: 'localhost',
+ port: s.address().port,
+ agent: agent,
+ path: `/${i}`,
+ }, common.mustCall((res) => {
+ assert.strictEqual(res.statusCode, 200);
+ res.resume();
+ res.on('end', common.mustCall(() => {
+ for (const key of Object.keys(agent.sockets)) {
+ assert(agent.sockets[key].length <= maxSockets);
+ }
+ const totalSocketsCount = getTotalSocketsCount();
+ assert(totalSocketsCount <= maxTotalSockets);
+ countdown.dec();
+ }));
+ }));
+ }
+}
+
+function getTotalSocketsCount() {
+ let num = 0;
+ for (const key of Object.keys(agent.sockets)) {
+ num += agent.sockets[key].length;
+ }
+ return num;
+}
+
+function getRequestCount() {
+ let num = 0;
+ for (const key of Object.keys(agent.requests)) {
+ num += agent.requests[key].length;
+ }
+ return num;
+}
+
+server.listen(0, common.mustCall(() => handler(server)));
+server2.listen(0, common.mustCall(() => handler(server2)));
+