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Change how long Netdata stores metrics

The Netdata Agent uses a custom made time-series database (TSDB), named the dbengine, to store metrics.

The default settings retain approximately two day's worth of metrics on a system collecting 2,000 metrics every second, but the Netdata Agent is highly configurable if you want your nodes to store days, weeks, or months worth of per-second data.

The Netdata Agent uses the following three fundamental settings in netdata.conf to change the behavior of the database engine:

[global]
    dbengine page cache size = 32
    dbengine multihost disk space = 256
    storage tiers = 1

dbengine page cache size sets the maximum amount of RAM (in MiB) the database engine uses to cache and index recent metrics. dbengine multihost disk space sets the maximum disk space (again, in MiB) the database engine uses to store historical, compressed metrics and storage tiers specifies the number of storage tiers you want to have in your dbengine. When the size of stored metrics exceeds the allocated disk space, the database engine removes the oldest metrics on a rolling basis.

Calculate the system resources (RAM, disk space) needed to store metrics

You can store more or less metrics using the database engine by changing the allocated disk space. Use the calculator below to find the appropriate value for the dbengine based on how many metrics your node(s) collect, whether you are streaming metrics to a parent node, and more.

You do not need to edit the dbengine page cache size setting to store more metrics using the database engine. However, if you want to store more metrics specifically in memory, you can increase the cache size.

:::tip

We advise you to visit the tiering mechanism reference. This will help you configure the Agent to retain metrics for longer periods.

:::

:::caution

This calculator provides an estimation of disk and RAM usage for metrics usage. Real-life usage may vary based on the accuracy of the values you enter below, changes in the compression ratio, and the types of metrics stored.

:::

Download the calculator to optimize the data retention to your preferences. Utilize the "Front" spreadsheet. Experiment with the variables which are padded with yellow to come up with the best settings for your use case.

Edit netdata.conf with recommended database engine settings

Now that you have a recommended setting for your Agent's dbengine, open netdata.conf with edit-config and look for the [db] subsection. Change it to the recommended values you calculated from the calculator. For example:

[db]
   mode = dbengine
   storage tiers = 3
   update every = 1
   dbengine multihost disk space MB = 1024
   dbengine page cache size MB = 32
   dbengine tier 1 update every iterations = 60
   dbengine tier 1 multihost disk space MB = 384
   dbengine tier 1 page cache size MB = 32
   dbengine tier 2 update every iterations = 60
   dbengine tier 2 multihost disk space MB = 16
   dbengine tier 2 page cache size MB = 32

Save the file and restart the Agent with sudo systemctl restart netdata, or the appropriate method for your system, to change the database engine's size.

What's next?

If you have multiple nodes with the Netdata Agent installed, you can stream metrics from any number of child nodes to a _ parent_ node and store metrics using a centralized time-series database. Streaming allows you to centralize your data, run Agents as headless collectors, replicate data, and more.

Storing metrics with the database engine is completely interoperable with exporting to other time-series databases. With exporting, you can use the node's resources to surface metrics when viewing dashboards, while also archiving metrics elsewhere for further analysis, visualization, or correlation with other tools.

Related reference documentation