Ecosystemconfigjs

Ecosystemconfigjs, commonly referred to by the file name ecosystem.config.js, is a configuration file used by the PM2 process manager to declare and manage multiple Node.js applications within a single project. It provides a centralized, JavaScript-based mechanism to define how applications should be started, monitored, and scaled in production or development environments.

The file exports a JavaScript object, typically with an apps array that lists each application to be managed. Each app entry can specify properties such as name, script (the entry point), instances (a number or max), exec_mode (cluster or fork), watch and ignore_watch, max_memory_restart, and environment blocks like env and env_production to control environment variables per stage. A separate deploy section may be included to configure automated deployments via PM2's deployment workflow.

Begin using it by running pm2 start ecosystem.config.js. PM2 reads the file and launches the configured processes, enabling clustering for multi-core CPUs when requested, automatic restarts on crashes, log aggregation, and status reporting. Environment-specific blocks allow switching variables for development versus production, and deploy settings enable push-based deployment to remote targets.

This configuration is a widely used, PM2-specific convention for managing multiple Node.js applications, and it is commonly checked into version control alongside application code. It provides portability and repeatability for process management but is not part of a universal Node.js specification.