Send metrics from MongoDB to Prometheus

A simple guide to send metrics from MongoDB to Prometheus in just a few minutes.
type: tutorialdomain: sourcesdomain: sinkssource: mongodb_metricssink: prometheus_remote_write

Metrics are an essential part of observing any service; without them you'll have significant blind spots. But collecting and analyzing them can be a real challenge -- especially at scale. Not only do you need to solve the basic task of collecting your metrics, but you must do it in a reliable, performant, and robust manner. Nothing is more frustrating than having your metrics pipeline fall on it's face during an outage, or even worse, cause the outage!

Fear not! In this guide we'll build an observability pipeline that will send metrics from MongoDB to Prometheus.

Background

What is MongoDB?

MongoDB is a general purpose, document-based, distributed database built for modern application developers and for the cloud era.

What is Prometheus?

Prometheus is a pull-based monitoring system that scrapes metrics from configured endpoints, stores them efficiently, and supports a powerful query language to compose dynamic information from a variety of otherwise unrelated data points.

Strategy

How This Guide Works

We'll be using Vector to accomplish this task. Vector is a popular open-source observability data platform. It's written in Rust, making it lightweight, ultra-fast and highly reliable. And we'll be deploying Vector as a agent.

Vector daemon deployment strategyVector daemon deployment strategy
1. Your service logs to STDOUT
STDOUT follows the 12 factor principles.
2. STDOUT is captured
STDOUT is captured and sent to an MongoDB instance.
3. Vector collects & fans-out data
Vector will sends metrics to [Prometheus](https://prometheus.io/).

What We'll Accomplish

We'll build an observability data platform that:

  • Collects metrics from MongoDB.
    • Enriches data with useful MongoDB context.
    • Efficiently collects data and checkpoints read positions to ensure data is not lost between restarts.
  • Sends metrics to Prometheus.
    • Compresses data to optimize bandwidth.
    • Automatically retries failed requests, with backoff.
    • Securely transmits data via Transport Layer Security (TLS).
    • Batches data to maximize throughput.

All in just a few minutes!

Tutorial

  1. Install Vector

    curl --proto '=https' --tlsv1.2 -sSf https://sh.vector.dev | sh
  2. Configure Vector

    cat <<-'VECTORCFG' > ./vector.toml
    [sources.mongodb_metrics]
    type = "mongodb_metrics"
    endpoints = [ "mongodb://localhost:27017" ]
    [sinks.out]
    type = "prometheus_remote_write"
    inputs = [ "mongodb_metrics" ]
    endpoint = "https://localhost:8087/"
    VECTORCFG
  3. Start Vector

    vector --config ./vector.toml
  4. Observe Vector

    vector top
    explain this command

Next Steps

Vector is powerful tool and we're just scratching the surface in this guide. Here are a few pages we recommend that demonstrate the power and flexibility of Vector:

Vector Github repo 4k
Vector is free and open-source!
Vector getting started series
Get setup in just a few minutes
Vector documentation
Everything you need to know about Vector