feat: add app launch in parallel limit

lib/API/schema.json

@@ -148,6 +148,11 @@
  "docDefault": false,
  "docDescription": "Make the process wait for a process.send('ready')"
  },
+ "launch_limit": {
+ "type": "number",
+ "docDefault": 1,
+ "docDescription": "Maximum number of launching processes at a time"
+ },
  "instances": {
  "type": "number",
  "docDefault": 1,

lib/God.js

@@ -136,7 +136,14 @@ God.prepare = function prepare (env, cb) {
  env.instances = 1;
  }
 
- timesLimit(env.instances, 1, function (n, next) {
+ // app launch in parallel limit
+ if (env.launch_limit != null) {
+ env.launch_limit = parseInt(env.launch_limit);
+ }
+ if (!env.launch_limit || env.launch_limit < 0) {
+ env.launch_limit = 1;
+ }
+ timesLimit(env.instances, env.launch_limit, function (n, next) {
  env.vizion_running = false;
  if (env.env && env.env.vizion_running) {
  env.env.vizion_running = false;

test/programmatic/graceful.mocha.js

@@ -173,6 +173,70 @@ describe('Wait ready / Graceful start / restart', function() {
 
  });
 
+ describe('(Cluster): Launching limit feature', function () {
+ this.timeout(10000);
+
+ after(function(done) {
+ pm2.delete('all', done);
+ });
+
+ it('Should launch app processes in parallel', function(done) {
+ pm2.start({
+ script : './wait-ready.js',
+ instances : 3,
+ launch_limit: 2,
+ exec_mode : 'cluster',
+ name : 'launching-limit-1'
+ });
+
+ setTimeout(function() {
+ pm2.list(function(err, apps) {
+ should(apps[0].pm2_env.status).eql('online');
+ should(apps[1].pm2_env.status).eql('online');
+ should(apps[2].pm2_env.status).eql('online');
+ pm2.delete('all', done);
+ })
+ }, 500);
+ });
+
+ it('Should launch app processes in parallel and limit launching processes on wait ready', function(done) {
+ pm2.start({
+ script : './wait-ready.js',
+ listen_timeout : 2000,
+ wait_ready : true,
+ instances : 3,
+ launch_limit: 2,
+ exec_mode : 'cluster',
+ name : 'launching-limit-2'
+ });
+
+ setTimeout(function() {
+ pm2.list(function(err, apps) {
+ should(apps[0].pm2_env.status).eql('launching');
+ should(apps[1].pm2_env.status).eql('launching');
+ should(apps[2]).undefined();
+ });
+ }, 500);
+
+ setTimeout(function() {
+ pm2.list(function(err, apps) {
+ should(apps[0].pm2_env.status).eql('online');
+ should(apps[1].pm2_env.status).eql('online');
+ should(apps[2].pm2_env.status).eql('launching');
+ })
+ }, 1500);
+
+ setTimeout(function() {
+ pm2.list(function(err, apps) {
+ should(apps[0].pm2_env.status).eql('online');
+ should(apps[1].pm2_env.status).eql('online');
+ should(apps[2].pm2_env.status).eql('online');
+ done();
+ })
+ }, 2500);
+ });
+ });
+
  describe('(Cluster): Wait ready feature', function () {
  this.timeout(10000);
 

types/index.d.ts

@@ -383,6 +383,10 @@ export interface StartOptions {
  * when you want your application to be considered as ready.
  */
  wait_ready?: boolean;
+ /**
+ * (Default: 1) Maximum number of launching processes at a time on application startup.
+ */
+ launch_limit?: number;
  /**
  * (Default: 1600)
  * The number of milliseconds to wait after a stop or restart command issues a SIGINT signal to kill the
@@ -446,7 +450,7 @@ export interface StartOptions {
 
 interface ReloadOptions {
  /**
- * (Default: false) If true is passed in, pm2 will reload it’s environment from process.env 
+ * (Default: false) If true is passed in, pm2 will reload it’s environment from process.env
  * before reloading your process.
  */
  updateEnv?: boolean;