Unable to restart Node.js app after PM2 delete - node.js

Question

I usually do pm2 stop to stop my application and it works fine.
However, when I just tried the pm2 delete on my app and starting it again, it doesn't seem to work anymore.
This is the pm2 error log I retrieved. No code was changed so I think it might be some ECONNRESET error from abrupt shutdown? (there wasn't any cleanup code)
Also tried killing the pid of pm2 and mongod when I find it using ps -ef and also pm2 kill and restarting of mongod to no avail.
Error: Invalid mongodb uri. Must begin with "mongodb://"
Received: NaN
at muri (/home/ubuntu/portal/node_modules/muri/lib/index.js:28:11)
at NativeConnection.Connection.openUri (/home/ubuntu/portal/node_modules/mongoose/lib/connection.js:713:18)
at Mongoose.createConnection (/home/ubuntu/portal/node_modules/mongoose/lib/index.js:198:17)
at Object.<anonymous> (/home/ubuntu/portal/models/stopwords.js:11:19)
at Module._compile (module.js:573:30)
at Object.Module._extensions..js (module.js:584:10)
at Module.load (module.js:507:32)
at tryModuleLoad (module.js:470:12)
at Function.Module._load (module.js:462:3)
at Module.require (module.js:517:17)
at require (internal/module.js:11:18)
at Object.<anonymous> (/home/ubuntu/portal/helpers/database/helper_mongodb.js:2:19)
at Module._compile (module.js:573:30)
at Object.Module._extensions..js (module.js:584:10)
at Module.load (module.js:507:32)
at tryModuleLoad (module.js:470:12)
at Function.Module._load (module.js:462:3)
at Module.require (module.js:517:17)
at require (internal/module.js:11:18)
at Object.<anonymous> (/home/ubuntu/portal/controllers/inf_controller.js:2:19)
at Module._compile (module.js:573:30)
at Object.Module._extensions..js (module.js:584:10)
Code for stopwords.js:11:19 is
let db = mongoose.createConnection(process.env.MONGODB_URI + process.env.MONGODB_HELPER_DB, { useMongoClient: true })

Answer 1

As we commented, and as you did, I also solved my problems using pm2
+ grunt to run my express.js app. Will try to explain here the solution to close the question.
The way to start and stop pm2 with different apps and without trouble
was with an ecosystem file where I configured my node apps.(centOS apache)
my ecosystem file
-bash-4.2$ pm2 ecosystem
File /var/www/vhosts/domain.com/ecosystem.config.js
[...]
-bash-4.2$ cat ecosystem.config.js
module.exports = {
/**
* Application configuration section
* http://pm2.keymetrics.io/docs/usage/application-declaration/
*/
apps : [
// First application
{
name : 'DomainProd',
cwd : '/var/www/vhosts/domain.com/httpdocs/App',
script : 'start.sh'
},
{
name : 'DomainTest',
cwd : '/var/www/vhosts/domain.com/testing.domain.com/httpdocs/App',
script : 'start-test.sh'
}
]
};
the start.sh script
-bash-4.2$ cat /var/www/vhosts/domain.com/httpdocs/App/start.sh
/usr/bin/grunt serve:prod
-bash-4.2$
The serve task on my Gruntfile
return grunt.task.run(['concurrent:cleanandbuild', 'build', 'env:all', 'env:prod', 'express:prod', 'wait', 'express-keepalive']);
The run example:
-bash-4.2$ pm2 status
┌────────────┬────┬──────┬───────┬────────┬─────────┬────────┬─────┬────────────┬──────────┐
│ App name │ id │ mode │ pid │ status │ restart │ uptime │ cpu │ mem │ watching │
├────────────┼────┼──────┼───────┼────────┼─────────┼────────┼─────┼────────────┼──────────┤
│ DomainProd │ 0 │ fork │ 17992 │ online │ 63 │ 20D │ 0% │ 264.1 MB │ disabled │
│ DomainTest │ 1 │ fork │ 25526 │ online │ 295 │ 113m │ 0% │ 1.2 MB │ disabled │
└────────────┴────┴──────┴───────┴────────┴─────────┴────────┴─────┴────────────┴──────────┘
Use `pm2 show <id|name>` to get more details about an app
-bash-4.2$ pm2 stop 1
[PM2] Applying action stopProcessId on app [1](ids: 1)
[PM2] [Domainest](1) ✓
┌────────────┬────┬──────┬───────┬─────────┬─────────┬────────┬─────┬────────────┬──────────┐
│ App name │ id │ mode │ pid │ status │ restart │ uptime │ cpu │ mem │ watching │
├────────────┼────┼──────┼───────┼─────────┼─────────┼────────┼─────┼────────────┼──────────┤
│ DomainProd │ 0 │ fork │ 17992 │ online │ 63 │ 20D │ 0% │ 264.1 MB │ disabled │
│ DomainTest │ 1 │ fork │ 0 │ stopped │ 295 │ 0 │ 0% │ 0 B │ disabled │
└────────────┴────┴──────┴───────┴─────────┴─────────┴────────┴─────┴────────────┴──────────┘
Use `pm2 show <id|name>` to get more details about an app
-bash-4.2$ pm2 start 1
[PM2] Applying action restartProcessId on app [1](ids: 1)
[PM2] [DomainTest](1) ✓
[PM2] Process successfully started
┌────────────┬────┬──────┬───────┬────────┬─────────┬────────┬─────┬────────────┬──────────┐
│ App name │ id │ mode │ pid │ status │ restart │ uptime │ cpu │ mem │ watching │
├────────────┼────┼──────┼───────┼────────┼─────────┼────────┼─────┼────────────┼──────────┤
│ DomainProd │ 0 │ fork │ 17992 │ online │ 63 │ 20D │ 0% │ 264.1 MB │ disabled │
│ DomainTest │ 1 │ fork │ 29816 │ online │ 295 │ 0s │ 0% │ 1.2 MB │ disabled │
└────────────┴────┴──────┴───────┴────────┴─────────┴────────┴─────┴────────────┴──────────┘
Use `pm2 show <id|name>` to get more details about an app
-bash-4.2$ pm2 logs 1
[TAILING] Tailing last 15 lines for [1] process (change the value with --lines option)
/var/www/vhosts/domain.com/.pm2/logs/DomainTest-out-1.log last 15 lines:
1|DomainTe | Execution Time (2017-10-02 19:33:24 UTC+2)
1|DomainTe | loading tasks 579ms ▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ 92%
1|DomainTe | clean:server 47ms ▇▇▇▇ 7%
1|DomainTe | Total 632ms
1|DomainTe |
1|DomainTe | Running "clean:dist" (clean) task
1|DomainTe | >> 5 paths cleaned.
1|DomainTe |
1|DomainTe | Done, without errors.
1|DomainTe |
1|DomainTe |
1|DomainTe | Execution Time (2017-10-02 19:33:24 UTC+2)
1|DomainTe | loading tasks 570ms ▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ 55%
1|DomainTe | clean:dist 456ms ▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇ 44%
1|DomainTe | Total 1s
[STREAMING] Now streaming realtime logs for [1] process
Hope it helps anyone arriving here.