Friday, 10 November 2017

Node.js process monitoring

In previous blog post, we have seen how we can write custom exporters for process monitoring and get metrics in prometheus.Suppose, I want to monitor node.js application with prometheus. we can write our own shell script which will monitor my node.js process and send metrics to prometheus.

Wait… Before directly jump to script I should consider options available for monitoring node.js process. PM2 is great process manager for node.js. Installing PM2 is very easy.

# npm install pm2 -g

With PM2 you can start/stop node.js process and  monitor CPU,Memory of process.You don’t need to worry about what if my node process is crashed due to any runtime issue. PM2 will restart it and maintain restart count of process.PM2 provide many metrics about process like uptime,restart count ,CPU,Memory , start time , log path etc.

So, what we can do is we can format pm2 metrics in the prometheus acceptable format .I will be easy for us to monitor node.js along with all other process and have one common dashboard for all process in your application. Also we can set alerts in prometheus alert manager when CPU / Memory utilization of node.js process exceeds peak value.

Here is sample script for scraping metrics data from nodejs process using pm2 .
#Author Priyanka Dive,Pravin Magdum
echo "Script to send pm2 status to Prometheus"
while true
pm2 list | grep ""
if [ "$?" == 0 ]
echo $linecount
pm2 list|head -n-2|tail -n+$linecount|awk  '{ print $2"_restart_count" "\t" $12 "\n" $2"_CPU_Usage" "\t" substr($16,1,  length($16)-1) "\n" $ 2"_MEMORY_Usage" "\t"
}'|sed 's/-/_/g' > Metrics/pm2_Merics.prom
sleep 10s             

Running script:
Create Metrics directory where we will store .prom files.
#mkdir Metrics

Run script as follows
#<Path-to-script>/ > /<Path-to-script>/pm2_exporter.log

Script will collect metrics in Metrics directory in the form of .prom files.We need to restart our node_exporter and pass path of Metrics directory to it as textfile collector.

Restart node Exporter:

Now, node exporter will scrape all metrics present in Metrics directory which includes our node.js process CPU,Memory etc. You can set alerts for this metrics and form dashboard in grafana which will display all information about your node.js process on screen.

Stay tuned will see Nginx monitoring with prometheus in next post..!!


  1. Replies
    1. IEEE Final Year Project centers make amazing deep learning final year projects ideas for final year students Final Year Projects for CSE to training and develop their deep learning experience and talents.

      IEEE Final Year projects Project Centers in India are consistently sought after. Final Year Students Projects take a shot at them to improve their aptitudes, while specialists like the enjoyment in interfering with innovation.

      corporate training in chennai corporate training in chennai

      corporate training companies in india corporate training companies in india

      corporate training companies in chennai corporate training companies in chennai

      I have read your blog its very attractive and impressive. I like it your blog. Digital Marketing Company in Chennai

  2. Its a nice post thank you for sharing and its very interesting....
    Best Oracle Training in Bangalore

  3. Learn Amazon Web Services for excellent job opportunities from Infycle Technologies, the Excellent AWS Training in Chennai. Infycle Technologies gives the most trustworthy AWS course in Chennai, with full hands-on practical training from professional trainers in the field. Along with that, the placement interviews will be arranged for the candidates, so that, they can meet the job interviews without missing them. To transform your career to the next level, call 7502633633 to Infycle Technologies and grab a free demo to know more


Amazon EKS - Kubernetes on AWS

By Komal Devgaonkar Amazon Elastic Container Service for Kubernetes (Amazon EKS), which is highly available and scalable AWS service....