How Do I Write an "Or" Logical Operator on Prometheus or Grafana
In Prometheus and Grafana, you can implement an "OR" logical operation using the or operator in Prometheus Query Language (PromQL) or by structuring queries appropriately in Grafana. Here’s how to use the "OR" operator effectively in both contexts.
Using the or Operator in PromQL
The or operator allows you to combine multiple metrics or expressions. When either condition is true, the combined result will be true.
Syntax
metric1 or metric2
Example 1: Basic Usage of or
Assuming you have two metrics, http_requests_total{status="200"} and http_requests_total{status="500"}, and you want to retrieve data where either status is present:
http_requests_total{status="200"} or http_requests_total{status="500"}
This query will return results for both the 200 and 500 HTTP status codes.
Example 2: Combining Metrics with or
You can also use the or operator to combine different metrics. For example, if you have a metric for HTTP requests and another for error rates:
http_requests_total or http_errors_total
This will return data from both metrics where either exists.
Step 2: Using the or Operator in Grafana
When writing queries in Grafana using Prometheus as a data source, you can use the or operator in the query editor just as you would in a standard Prometheus query.
- Open your Grafana dashboard and add a new panel.
- In the query editor, enter your PromQL expression using the
oroperator. - Execute the query to see the combined results.
Example in Grafana
If you want to visualize requests or errors, you can input:
sum(rate(http_requests_total[5m])) or sum(rate(http_errors_total[5m]))
This query would provide a time series showing either the rate of requests or the rate of errors over the last 5 minutes.
Considerations
- Label Matching: When using
or, ensure that the metrics being combined share relevant labels if you expect to compare them directly. Mismatched labels may result in empty results. - Result Handling: The result of an
oroperation will be a vector that combines the matching time series, which can be useful for comparisons or aggregations in Grafana visualizations.
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
-
What is the Difference Between a Gauge and a Counter?
Gauges and counters are two core metric types in Prometheus. They serve different purposes and are used to track different kinds of data. 1. Counter A counter is a metric that only increases over t...
Questions -
Do I Understand Prometheus's Rate Vs Increase Functions Correctly?
Understanding the rate and increase functions in Prometheus is crucial for accurately analyzing time-series data. Here's a detailed breakdown of both functions and their differences to ensure you h...
Questions -
How to Calculate Containers' Cpu Usage in Kubernetes With Prometheus as Monitoring?
To calculate CPU usage for containers in a Kubernetes cluster using Prometheus, you need to set up Prometheus to scrape metrics from your Kubernetes nodes and pods. Here’s a step-by-step guide on h...
Questions -
Limitations of Prometheus Labels
Prometheus labels are a powerful feature used to add dimensional data to metrics. However, improper use or lack of understanding of their limitations can lead to inefficiencies, high resource consu...
Questions