What is PromLTS?

PromLTS is a SaaS providing Long Term Storage for the Prometheus open source monitoring system.

Specifically, PromLTS solves the problem of reliably storing a large amount of time series data generated by Prometheus.

Why should I use PromLTS?

  • 3x redundancy for all data stored with us.
  • Store less data locally on your Prometheus instances, making them cheaper to run.
  • Use ephemeral Prometheus instances - stateless services are a lot easier to manage!
  • Lower total cost of ownership through the combination of the above efficiencies, and the economies of scale offered by our multitenant service.
  • Keep a long term view of your Prometheus data without the headache of managing a huge amount of stored data.
  • No need to back up your Prometheus data, which can be many terabytes if you're keeping a lot of history.
  • PromLTS is maintained by an experienced team of on-call engineers.
  • You benefit from continuous active development, we add new features regularly and you don't spend time (or risk) on upgrades.
  • Optionally, an SLA if your business demands it.

How do I get my data into PromLTS?

The short answer: Adding small remote_read and remote_write sections to your prometheus.yml configuration file.

The longer answer: Full instructions, with diagrams and a config snippet, are in our Getting Started guide. If you have any trouble at all, please send us an email and we'll get back to you quickly.

How do I get help?

The short answer: please email and we'll get back to you quickly.

The longer answer: There's some more detail on our Getting Help page about how to contact us for different issues, business hours, billing questions, etc.

How do you handle redundancy?

Our backend stores three redundant copies of each datapoint in our distributed, fault-tolerant, eventually-consistent database. In addition, our backend design is heavily focused on eliminating single points of failure. We're happy to share deep architectural details with our larger customers - please get in touch if that's a thing you'd like to learn more about.

In CAP theorem terms, we provide availability and partition-tolerance.

Why should I trust you?

We've been doing this for a long, long time - longer than Prometheus has been around! PromLTS is run by a company called Metricfire, which has been building and maintaining Hosted Graphite since 2011. We handle billions of datapoints per day from thousands of engineers around the world, and, if we can suppress our naturally Irish urge to be self-deprecating for just a moment, we think we're pretty damn good at managing a huge amount of time-series data on behalf of all our customers.

A lot of big brands trust us with their critical monitoring data, and we hope that you will too. If you have questions about any aspect of our service, please get in touch. We'll give you deeply technical answers about our stack, our security posture, our processes, etc. If you want to set up a call with a founder or with some of our biggest customers to get the real story, send us an email ( and let's talk.

Do you downsample my data?

Yes. Prometheus, by design, does not downsample any data, which makes it a challenge to store the full 'raw' resolution because it's a huge amount of data to store and process for display when you need to query it back. Past a certain point, downsampling of some kind is always required to keep data volume and query responsiveness within sensible ranges.

Using your local Prometheus in combination with PromLTS gives you the best of both worlds - high precision "raw" data from your local Prometheus for queries on recent data, and fast, accurately downsampled data for queries on data up to two years in the past.

What resolutions do you downsample my data to?

PromLTS supports two downsampled resolutions:

  • 300s (five minutes)
  • 3600s (one hour)

How long is my data kept for?

The short answer: 2 years.

The longer answer: Data retention depends on the resolution the data is stored at. It's much less intensive to store and maintain finer-resolution data for a long time, so here's what we store:

  • 300s resolution is stored for 6 months.
  • 3600s resolution is stored for 2 years.

How is my data isolated from other users?

By default, your downsampled timeseries data is stored in a large multitenant distributed database.

If data isolation is a serious concern for you, we can offer full hardware-level isolation at the storage layer, or at the storage and querying layers, depending on your needs. Talk to us:

How do you secure your services?

We have a security FAQ that we're happy to share with you - please get in touch.

What jurisdiction is my data kept in?

All our servers are in Germany - near Frankfurt, to be more specific. If you have a legal or regulatory reason for needing to store your data somewhere else, please talk to us by emailing