PM2 is a process manager for Node.js applications. It allows you to easily manage and monitor your applications, and also provides features such as automatic restarts, log management, and clustering.
One of the key features of PM2 is its built-in log management. PM2 automatically manages log files for your applications and can rotate them based on size or time. It also allows you to easily access and view the logs for your applications.
To use PM2's log management features, you first need to start your application with PM2. You can do this by running the following command:
pm2 start myapp.js
This will start your application and also begin logging its output to a file. By default, PM2 will create a new log file every day and keep the last 15 log files.
You can access the logs for your application by running the following command:
pm2 logs myapp
This will display the logs for your application in the terminal. You can also specify the number of lines to display by using the -n option:
pm2 logs myapp -n 100
This will display the last 100 lines of the log.
You can also configure PM2 to rotate your logs based on size or time. To rotate your logs based on size, you can use the --log-date-format option:
pm2 start myapp.js --log-date-format="YYYY-MM-DD_HH-mm-ss"
This will create a new log file every hour.
You can also configure PM2 to rotate your logs based on time by using the --log-date-format option:
pm2 start myapp.js --log-date-format="YYYY-MM-DD"
This will create a new log file every day.
In addition to these options, PM2 also allows you to redirect the logs for your application to a remote server using the --merge-logs option. This can be useful if you want to collect and analyze your logs using a centralized logging service such as Logstash or Elasticsearch.
pm2 start myapp.js --merge-logs
In summary, PM2 provides a built-in log management system that makes it easy to access and rotate log files for your Node.js applications. It also provides options to redirect logs to a remote server for centralized logging and analysis.
In addition to its log management features, PM2 also provides a number of other useful features for managing and monitoring Node.js applications.
One of the key features of PM2 is its ability to automatically restart applications that have crashed or stopped. This can be useful for ensuring that your applications are always running and available to users. You can enable this feature by using the --watch option when starting your application:
pm2 start myapp.js --watch
This will automatically restart your application if it crashes or is stopped.
Another useful feature of PM2 is its ability to cluster applications. Clustering allows you to run multiple instances of an application on different CPU cores, which can improve performance and increase the reliability of your application. You can enable clustering by using the -i option when starting your application:
pm2 start myapp.js -i 4
This will start 4 instances of your application, one on each CPU core.
PM2 also provides a web-based interface for monitoring and managing your applications. This interface, called PM2 Plus, allows you to view real-time statistics and logs for your applications, as well as perform actions such as restarting or stopping applications. To use PM2 Plus, you'll need to sign up for an account and then link it to your PM2 installation.
PM2 also provides the ability to manage the application process easily, for example, you can stop and start your application by using the following command :
pm2 stop myapp
pm2 start myapp
You can also list all running processes by using :
pm2 list
In summary, PM2 is a powerful process manager for Node.js applications that provides a number of useful features for managing and monitoring your applications. Its log management, automatic restarts, clustering and web-based interface, process management make it a great choice for running production-grade Node.js applications.
Popular questions
- What is PM2 and what does it do?
PM2 is a process manager for Node.js applications. It allows you to easily manage and monitor your applications, and also provides features such as automatic restarts, log management, and clustering.
- How does PM2 handle log management for Node.js applications?
PM2 automatically manages log files for your applications and can rotate them based on size or time. It also allows you to easily access and view the logs for your applications.
- What command can be used to start an application with PM2 and begin logging its output to a file?
pm2 start myapp.js
- How can you configure PM2 to rotate your logs based on size or time?
To rotate your logs based on size, you can use the --log-date-format option:
pm2 start myapp.js --log-date-format="YYYY-MM-DD_HH-mm-ss"
To rotate your logs based on time, you can use the --log-date-format option:
pm2 start myapp.js --log-date-format="YYYY-MM-DD"
- What command can be used to redirect the logs for an application to a remote server for centralized logging and analysis?
pm2 start myapp.js --merge-logs
This command will redirect the logs for the application to a remote server for centralized logging and analysis.
Tag
Node.js
