Brazil - Prometheus: Up & Running

by Brian Brazil

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• July 2018: First Edition

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978-1-492-03414-8

[LSI]

This book describes in detail how to use the Prometheus monitoring system to monitor, graph, and alert on the performance of your applications and infrastructure. This book is intended for application developers, system administrators, and everyone in between.

When it comes to monitoring, knowing that the systems you care about are turned on is important, but thats not where the real value is. The big wins are in understanding the performance of your systems.

By performance I dont only mean the response time of and CPU used by each request, but the broader meaning of performance. How many requests to the database are required for each customer order that is processed? Is it time to purchase higher throughput networking equipment? How many machines are your cache misses costing? Are enough of your users interacting with a complex feature in order to justify its continued existence?

These are the sort of questions that a metrics-based monitoring system can help you answer, and beyond that help you dig into why the answer is what it is. I see monitoring as getting insight from throughout your system, from high-level overviews down to the nitty-gritty details that are useful for debugging. A full set of monitoring tools for debugging and analysis includes not only metrics, but also logs, traces, and profiling; but metrics should be your first port of call when you want to answer systems-level questions.

Prometheus encourages you to have instrumentation liberally spread across your systems, from applications all the way down to the bare metal. With instrumentation you can observe how all your subsystems and components are interacting, and convert unknowns into knowns.