Prometheus High Availability and Fault Tolerance Strategy

Need more reliable system monitoring? Learn to configure Prometheus high availability and fault tolerance settings for maximum performance.

Digital Analytics
8 min
Digital Analytics
Prometheus High Availability and Fault Tolerance Strategy

In today’s competitive market, gaining a competitive edge requires more than innovation. The speed at which companies innovate can make the difference between success or failure.

The key to speed is applications that can provide real-time data.

With real-time insight into company metrics, leaders can make informed strategic decisions. When these systems fail, the business risks making uninformed decisions.

Here, we’ll discuss Prometheus's high availability and fault tolerance as a technology strategy to monitor these systems to ensure they remain available for use.

What is Prometheus and why it's important?

Prometheus refers to a technology stack for monitoring and alerting for cloud-native apps.

Metrics of Prometheus can be used to monitor and record different statistics in real-time such as top selling products, orders, product reviews etc.

SoundCloud initially developed the tool and later donated it to the open-source community.

The purpose of designing Prometheus was to create a system where you could go when outages occurred and diagnose problems quickly.

Prometheus architecture and its components

Because of Prometheus server independence, even when other parts of the infrastructure are broken, you can rely on Prometheus for running diagnoses and further more you don’t need to add extensive infrastructure to use it.

Benefits of Prometheus

Configuring Prometheus fault tolerance and high availability provides many benefits which include:


As developers add additional features and services, the system quickly grows.

The tool performs automatic service detection. It keeps track of all endpoints to ensure necessary metrics are discovered.

Outage Recovery

Developers can get immediate alerts if the tool does not receive data from an endpoint. As a result, Developers can quickly locate the issue and resolve problems.


Prometheus receives requests every 15 seconds but does not put a heavy load on the system.

It uses memory rather than disk space while it captures and converts metrics.

Traffic Control

High-volume data can overload a system. However, the tool only receives information by request rather than push.

High availability vs. Fault tolerance

High availability and fault tolerance are often used interchangeably. While they are similar, some differences should be noted.

Fault tolerance

Fault tolerance is a strategy that offers a guarantee of “no downtime.” This strategy uses specialized hardware to detect faults.

Once an issue is detected the system instantaneously switches to a redundant server.

The fault-tolerant strategy, while beneficial, comes at a high cost. Businesses waste money on redundant hardware that isn’t used unless the system fails.

Another downside to this strategy is that it only addresses hardware issues and not software problems.

Prometheus fault tolerance settings help IT teams monitor and plan for fault tolerance in systems.

High availability

High availability refers to a strategy that guarantees “minimal downtime.”

Systems with high availability monitor the system as a set of shared resources that work together to provide essential services.

Failure in one component can be quickly restored with minimal impact to the system.

Although this approach is not instantaneous, services are often restored in less than a minute.

Challenges with high availability

Realizing these benefits does not come without its challenges.

IT teams must address each of the below issues to ensure the monitoring system operates efficiently.


By default, the tool runs on one server that may be shared with other resources on the server. The amount of data Prometheus stores can quickly fill the server’s disk. Companies will need to either run a separate server or allocate additional storage to the existing server.


Redundancy can be messy with Prometheus. Because this strategy stores information to one location, you would need multiple instances to achieve redundancy.

Lack of Event-Driven Metrics

Prometheus works on a request model. This approach means the system may miss metrics for short-lived batch jobs.

Prometheus can work around this using a push gateway.

Scalability options

A high available fault-tolerant system is only as good as it can scale. As the business grows and collects more data, system usage increases.

The ability to scale to meet the additional demand is important. Below are several options to scale Prometheus.


Federation is a strategy where one of the Prometheus servers scrapes time-series data from another Prometheus server.

There are two approaches to Federation:

  • Hierarchical - With hierarchical federation, Prometheus stores data it scrapes from other servers in a tree-like structure.
  • Cross-Service - Using this approach, Prometheus pulls data from sibling Prometheus servers. The sibling servers contain data it has pulled from others. In this way, you can query any server for metrics.


Due to storage limitations, there may be a limit on how much traffic a Prometheus server can handle.

The more metrics the system gathers, the more disk space the process requires. Developers will need to use cloud-storage solutions to scale up or down as needed.

When speed and innovation count, it is important for business leaders to have access to the systems they need for informed decision-making.


Implementing a Prometheus fault tolerance and high availability monitoring solution enables IT teams to rapidly identify issues and get real time feedback on how the system is performing.

Thus, the systems performance will be optimized to run with minimal to no interruption.

The end result includes benefits such as productivity increment, more stable applications and overall more agile development processes.

Adservio makes sure to provide seamless integration of Prometheus for organizations that want to put their metrics work for them and not they way around.

Contact us to learn more how we can help you get the most from Prometheus high availability and fault tolerance strategies for having in place a resilient monitoring platform.

Published on
October 5, 2021

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