This blog post demonstrates how to build an agent-less system monitoring tool using Elixir and Broadway. It leverages SSH to remotely execute commands on target machines, collecting metrics like CPU usage, memory consumption, and disk space. Broadway manages the concurrent execution of these commands across multiple hosts, providing scalability and fault tolerance. The collected data is then processed and displayed, offering a centralized overview of system performance. The author highlights the benefits of this approach, including simplified deployment (no agent installation required) and the inherent robustness of Elixir and its ecosystem. This method offers a lightweight yet powerful solution for monitoring server infrastructure.
This blog post explores building a system monitoring solution using Elixir and Broadway, specifically focusing on an agent-less approach. The author argues that traditional agent-based monitoring, while offering granular data collection, introduces overhead and complexity through agent deployment and maintenance. Agent-less monitoring, leveraging protocols like SSH, offers a simplified alternative by querying systems directly without requiring resident software.
The post begins by outlining the conceptual architecture of their solution. It details how Broadway, a concurrent and fault-tolerant processing library in Elixir, acts as the central processing engine. It receives monitoring tasks, distributes them to designated workers, and manages the results. Crucially, the chosen agent-less method utilizes SSH to execute commands remotely on target systems. The post emphasizes Broadway's robustness in handling potentially unreliable network operations inherent in SSH-based communication.
The author then delves into the implementation specifics. They demonstrate setting up a Broadway pipeline configured to process monitoring tasks. These tasks are structured as messages containing the target hostname and the command to execute. The implementation leverages Erlang's SSH application to establish connections and execute commands remotely. A critical component highlighted is the error handling mechanism built around Broadway's retry and failure handling capabilities. This ensures resilience against transient network issues or temporary unavailability of target systems. The retrieved monitoring data is then processed and formatted, ready for storage or visualization.
A key advantage emphasized is the flexibility afforded by this approach. The system can be readily extended to support various monitoring commands and metrics. Adding new systems to monitor only requires configuring the necessary connection details, without deploying any agents. The post also touches upon the scalability of the solution. Broadway's concurrent processing model allows for parallel execution of monitoring tasks, improving efficiency and reducing overall monitoring time. The author acknowledges potential security considerations associated with managing SSH credentials and advocates for secure storage and access control mechanisms.
Finally, the post concludes by reiterating the benefits of the agent-less approach, highlighting its simplicity, scalability, and reduced overhead. It positions this approach as a compelling alternative to traditional agent-based solutions, especially in scenarios where agent deployment is impractical or undesirable. The author suggests potential future enhancements, such as integrating with different data visualization tools and exploring alternative agent-less protocols.
Summary of Comments ( 16 )
https://news.ycombinator.com/item?id=43090167
Hacker News users discussed the practicality and benefits of the agentless approach to system monitoring described in the linked blog post. Several commenters appreciated the simplicity and reduced overhead of not needing to install agents on monitored machines. Some raised concerns about potential security implications of running commands remotely via SSH and the potential performance bottlenecks of doing so. Others questioned the scalability of this method, particularly for large numbers of monitored systems. The discussion also touched on alternative approaches like using message queues and the potential benefits of Elixir's concurrency features for this type of monitoring system. A compelling comment suggested exploring the use of OSquery for efficient data gathering, which prompted further discussion on its pros and cons. Finally, some commenters expressed interest in the author's open-sourcing of their project.
The Hacker News post titled "Agent-Less System Monitoring with Elixir Broadway" sparked a small but focused discussion with 5 comments. No single comment overwhelmingly dominated the conversation, but several offered interesting perspectives on the article's topic.
One commenter questioned the term "agent-less," pointing out that while the system described doesn't require installing dedicated agent software on monitored machines, it still relies on SSH access, which functionally acts like an agent. They argued that this approach trades one set of tradeoffs (agent installation and maintenance) for another (managing SSH keys and potential security concerns).
Another comment focused on the choice of Erlang/Elixir for this type of task. They acknowledged the platform's strengths in concurrency and distributed systems but expressed concern about the operational overhead and debugging complexity compared to simpler scripting solutions, especially for smaller deployments. They suggested that the benefits of Elixir might become more pronounced with larger and more complex monitoring setups.
A third commenter praised the article's clear explanation and the elegant approach to building a robust monitoring system with Broadway. They highlighted the benefits of leveraging Elixir's OTP framework for handling failures and ensuring reliability.
The remaining comments were shorter and less substantive. One simply expressed appreciation for the article, while another briefly mentioned using a similar approach with a different technology.
Overall, the comments section, while brief, provided some thoughtful critiques and perspectives on the advantages and disadvantages of the proposed agent-less monitoring approach using Elixir and Broadway. The discussion centered on the practical implications of SSH as an "agent" substitute and the suitability of Elixir/OTP for this kind of task in different scales of deployment.