Merging upstream version 1.36.0.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 59 insertions, 36 deletions

diff --git a/docs/store/change-metrics-storage.md b/docs/store/change-metrics-storage.md
index 99760e8d..437b45fc 100644
--- a/docs/store/change-metrics-storage.md
+++ b/docs/store/change-metrics-storage.md
@@ -6,72 +6,95 @@ custom_edit_url: https://github.com/netdata/netdata/edit/master/docs/store/chang
 
 # Change how long Netdata stores metrics
 
-import { Calculator } from '../../src/components/agent/dbCalc/'
+The Netdata Agent uses a custom made time-series database (TSDB), named the [`dbengine`](/database/engine/README.md), to store metrics.
 
-The Netdata Agent uses a time-series database (TSDB), named the [database engine
-(`dbengine`)](/database/engine/README.md), to store metrics data. The most recently-collected metrics are stored in RAM,
-and when metrics reach a certain age, and based on how much system RAM you allocate toward storing metrics in memory,
-they are compressed and "spilled" to disk for long-term storage.
+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 default settings retain about 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 two settings in `netdata.conf` to change the behavior of the database engine:
+The Netdata Agent uses the following three fundamental settings in `netdata.conf` to change the behavior of the database engine:
 
 ```conf
 [global]
-    page cache size = 32
+    dbengine page cache size = 32
     dbengine multihost disk space = 256
+    storage tiers = 1
 ```
 
-`page cache size` sets the maximum amount of RAM (in MiB) the database engine uses to cache and index recent metrics.
+`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. When the size of stored metrics exceeds the allocated disk space, the database engine
-removes the oldest metrics on a rolling basis.
+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 an appropriate value for `dbengine multihost disk space` based on how many metrics your node(s) collect,
-whether you are streaming metrics to a parent node, and more.
+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](/database/engine/README.md#tiering) reference. This will help you
+configure the Agent to retain metrics for longer periods.
 
-You do not need to edit the `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.
+:::
 
-> ⚠️ This calculator provides an estimate of disk and RAM usage for **metrics storage**, along with its best
-> recommendation for the `dbengine multihost disk space` setting. 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.
+:::caution
 
-<Calculator />
+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](https://docs.google.com/spreadsheets/d/e/2PACX-1vTYMhUU90aOnIQ7qF6iIk6tXps57wmY9lxS6qDXznNJrzCKMDzxU3zkgh8Uv0xj_XqwFl3U6aHDZ6ag/pub?output=xlsx)
+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 `dbengine multihost disk space`, open `netdata.conf` with
-[`edit-config`](/docs/configure/nodes.md#use-edit-config-to-edit-configuration-files) and look for the `dbengine
-multihost disk space` setting. Change it to the value recommended above. For example:
+Now that you have a recommended setting for your Agent's `dbengine`, open `netdata.conf` with
+[`edit-config`](/docs/configure/nodes.md#use-edit-config-to-edit-configuration-files) and look for the `[db]`
+subsection. Change it to the recommended values you calculated from the calculator. For example:
 
 ```conf
-[global]
-    dbengine multihost disk space = 1024
+[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](/docs/configure/start-stop-restart.md) for your system, to change the database engine's size.
+Save the file and restart the Agent with `sudo systemctl restart netdata`, or
+the [appropriate method](/docs/configure/start-stop-restart.md) 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](/docs/metrics-storage-management/how-streaming-works.mdx) 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.
+If you have multiple nodes with the Netdata Agent installed, you
+can [stream metrics](/docs/metrics-storage-management/how-streaming-works.mdx) 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](/docs/export/external-databases.md). With exporting, you can use the node's resources to surface metrics
-when [viewing dashboards](/docs/visualize/interact-dashboards-charts.md), while also archiving metrics elsewhere for
-further analysis, visualization, or correlation with other tools. 
+Storing metrics with the database engine is completely interoperable
+with [exporting to other time-series databases](/docs/export/external-databases.md). With exporting, you can use the
+node's resources to surface metrics when [viewing dashboards](/docs/visualize/interact-dashboards-charts.md), while also
+archiving metrics elsewhere for further analysis, visualization, or correlation with other tools.
 
 ### Related reference documentation
 
 - [Netdata Agent · Database engine](/database/engine/README.md)
+- [Netdata Agent · Database engine configuration option](/daemon/config/README.md#[db]-section-options)