Monitoring Windows servers using Prometheus — wmi_exporter

3 min readApr 21, 2020

A DevOps engineer or a Site Reliability Engineer need to spend a lot of time monitoring their Windows servers.

And doing RCA on a Windows server when it goes down it not that easy task. Is it because of a high CPU usage on one of the processes?

Is the server having some memory issues? Is the RAM used too much on my Windows server?

Let’s start learning how to configure wmi_exporter in order to monitor Windows servers with Prometheus.

Prerequisites

To follow this tutorial you’ll need:

One Linux server set up
Prometheus 2.x installed on your server, including the Prometheus Web UI. You can find out your Prometheus version by running the prometheus -version command. The output contains your Prometheus version as well as build information.
PLEASE TAKE CARE OF YAML FILE INDENTATION :)

Windows Server Monitoring Architecture

The WMI exporter will run as a Windows service and it will be responsible for gathering metrics about your system

Installing the WMI Exporter

Download wmi_exporter msi installer from here -

martinlindhe/wmi_exporter

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github.com

We are using the latest version — https://github.com/martinlindhe/wmi_exporter/releases/download/v0.11.1/wmi_exporter-0.11.1-amd64.msi

Running the WMI installer

Run the msi installer and accept firewall exceptions if any.
To verify the installation go to Services panel of Windows and search for the “WMI exporter” entry in the list. Make sure the service is running properly.

Access the Windows Server metrics

Now that wmi_exporter is running, it should start exposing metrics on http://localhost:9182/metrics

Configure Prometheus in accordance to WMI exporter

Open your prometheus configuration file (mine is located at /etc/prometheus/prometheus.yml) and edit the following changes to your file at the end.
#cat /etc/prometheus/prometheus.yml

- file_sd_configs:
- files:
- /etc/prometheus/file_sd/wmi.yml
job_name: wmi_exporter
metrics_path: /metrics
scrape_interval: 5s

Add your windows targets to this file -

# cat /etc/prometheus/file_sd/wmi.yml

labels:
project: my_windows_hosts
targets:
- 192.168.0.100:9182

Configure Alert Rules -

- alert: WinHostOutOfMemory
expr: wmi_os_physical_memory_free_bytes{job=”wmi_exporter”} / wmi_cs_physical_memory_bytes{job=”wmi_exporter”} < 0.1
labels:
severity: warning
annotations:
summary: “Windows Host out of memory (instance {{ $labels.instance }})”
description: “Node memory is filling up (< 10% left)\n VALUE = {{ $value }}\n LABELS: {{ $labels }}”
- alert: WinHostCpuUsage
expr: 100 — (avg by (instance) (irate(wmi_cpu_time_total{job=”wmi_exporter”,mode=”idle”}[2m])) * 100) > 80
for: 10m
labels:
severity: warning
annotations:
summary: “CPU Usage (instance {{ $labels.instance }})”
description: “CPU Usage is more than 80%\n VALUE = {{ $value }}\n LABELS: {{ $labels }}”