What happens to a process when using monit?

Question

Nginx

There is such a situation. Nginx + NodeJS + Monit
set up everything in the right way.
nginx

server {
        listen 80 default_server;
        listen [::]:80 default_server ipv6only=on;
        root /usr/share/nginx/html;
        index index.php index.html index.htm;
        server_name localhost;
        location / {
                proxy_read_timeout 120s;
                proxy_pass http://127.0.0.1:3000;
                proxy_set_header Host $host;
                proxy_http_version 1.1;
                proxy_set_header Upgrade $http_upgrade;
                proxy_set_header Connection "upgrade";
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_set_header X-Real-IP $remote_addr;
        }

/etc/init/cloacker.conf

#cloacker.conf
description "node app"
author      "username"

start on startup
stop on shutdown

script
    export HOME="/root"

    echo $$ > /var/run/cloacker.pid
    exec /usr/bin/node /var/www/cloacker/app >> /var/log/cloacker.sys.log 2>&1
end script

pre-start script
    # Date format same as (new Date()).toISOString() for consistency
    echo "[`date -u +%Y-%m-%dT%T.%3NZ`] (sys) Starting" >> /var/log/cloacker.sys.log
end script

pre-stop script
    rm /var/run/cloacker.pid
    echo "[`date -u +%Y-%m-%dT%T.%3NZ`] (sys) Stopping" >> /var/log/cloacker.sys.log
end script

/etc/monit/conf.d/cloacker.conf

check process cloacker with pidfile /var/run/cloacker.pid
        start program = "/sbin/start cloacker"
        stop program = "/sbin/stop cloacker"
        if failed host localhost port 3000 then restart

It looks like it should work, BUT!
if we start it just
# start cloacker
everything works, the node processes requests and nothing falls, but it’s worth running it like this
# monit start cloacker
, messages fall into the log

tail -n 100 -f /var/log/cloacker.sys.log
    at Function.process_params (/var/www/cloacker/node_modules/express/lib/router/index.js:330:12)
[2015-12-21T17:02:43.173Z] (sys) Stopping
[2015-12-21T17:02:43.228Z] (sys) Starting
Example app listening at http://:::3000
TypeError: Cannot read property 'split' of undefined
    at IpDecoder.set6 (/var/www/cloacker/node_modules/mmdb-reader/src/IpDecoder.js:39:16)
    at IpDecoder.set (/var/www/cloacker/node_modules/mmdb-reader/src/IpDecoder.js:21:10)
    at Reader.lookup (/var/www/cloacker/node_modules/mmdb-reader/src/Reader.js:636:11)
    at /var/www/cloacker/app.js:15:25
    at Layer.handle [as handle_request] (/var/www/cloacker/node_modules/express/lib/router/layer.js:95:5)
    at next (/var/www/cloacker/node_modules/express/lib/router/route.js:131:13)
    at Route.dispatch (/var/www/cloacker/node_modules/express/lib/router/route.js:112:3)
    at Layer.handle [as handle_request] (/var/www/cloacker/node_modules/express/lib/router/layer.js:95:5)
    at /var/www/cloacker/node_modules/express/lib/router/index.js:277:22
    at Function.process_params (/var/www/cloacker/node_modules/express/lib/router/index.js:330:12)
[2015-12-21T17:02:44.311Z] (sys) Stopping
[2015-12-21T17:02:44.367Z] (sys) Starting
Example app listening at http://:::3000
TypeError: Cannot read property 'split' of undefined
    at IpDecoder.set6 (/var/www/cloacker/node_modules/mmdb-reader/src/IpDecoder.js:39:16)
    at IpDecoder.set (/var/www/cloacker/node_modules/mmdb-reader/src/IpDecoder.js:21:10)
    at Reader.lookup (/var/www/cloacker/node_modules/mmdb-reader/src/Reader.js:636:11)
    at /var/www/cloacker/app.js:15:25
    at Layer.handle [as handle_request] (/var/www/cloacker/node_modules/express/lib/router/layer.js:95:5)
    at next (/var/www/cloacker/node_modules/express/lib/router/route.js:131:13)
    at Route.dispatch (/var/www/cloacker/node_modules/express/lib/router/route.js:112:3)
    at Layer.handle [as handle_request] (/var/www/cloacker/node_modules/express/lib/router/layer.js:95:5)
    at /var/www/cloacker/node_modules/express/lib/router/index.js:277:22
    at Function.process_params (/var/www/cloacker/node_modules/express/lib/router/index.js:330:12)
[2015-12-21T17:02:45.458Z] (sys) Stopping
[2015-12-21T17:02:45.512Z] (sys) Starting

Well, of course, in the browser, I periodically get to an unresponsive page
where I did something wrong, I don’t know, but I still want to track and fix the moment when the application falls