atop vs PM2

atop is a free, GPL-licensed performance monitor for Linux. It uses a full-screen ASCII interface to report system and process activity at regular intervals. System-level views cover CPU, memory, swap, disk, and network activity. Process and thread views include CPU use, memory growth, disk use, and other statistics, including consumption by processes that finish during the interval. atop can save compressed raw counters for longer-term analysis, preserving daily logs for 28 days by default. The atopsar command turns those logs into system activity reports. It also reports CPU, memory, disk I/O utilization, and pressure for cgroup v2. An optional netatop kernel module adds per-process and per-thread TCP and UDP packet counts and bandwidth statistics. Displays can use bar graphs or detailed text, with columns adjusting to terminal width. Downloads list source and x86_64 RPM packages for version 2.13.0.

PM2 is a daemon process manager for managing applications and keeping them online. PM2 Runtime is an open-source process manager; PM2 Plus adds monitoring for Node.js production applications. Runtime supports cluster mode, zero-downtime reloads, watch and restart, startup scripts, log management and memory-based reloads. For containers, pm2-runtime can run Node.js applications with process fallback, flow control, monitoring and source-map support. PM2 Plus lists a web monitoring interface, application overview, issue tracking, custom metrics, server health checks and Node.js V8 monitoring. Its alerts include email and Slack notifications, while Enterprise adds rule-based alerting. The AI Assistant connects Claude, Cursor and other MCP-compatible assistants to monitoring data through OAuth with a PM2.io account. Documentation covers Docker, cloud providers, Heroku, AWS Elastic Beanstalk, Nginx and deployment workflows. Runtime costs nothing, and Plus costs $79 a month.