94f86eda79
* Some improvements for introduction/performance.md
* Minor improvements for example_datasets
* Add website/package-lock.json to .gitignore
* YT paragraph was badly outdated and there is no real reason to write a new one
* Use weird introduction article as a starting point for F.A.Q.
* Some refactoring of first half of ya_metrika_task.md
* minor
* Weird docs footer bugfix
* Forgotten redirect
* h/v scrollbars same size in docs
* CLICKHOUSE-3831: introduce security changelog
* A bit more narrow tables on docs front page
* fix flag in ru docs
* Save some space in top level of docs ToC
* Capitalize most words in titles of docs/en/
* more docs scrollbar fixes
* fix incorrect merge
* fix link
* fix switching languages in single page docs mode
* Update mkdocs & mkdocs-material + unminify javascript
* cherrypick 17e18d1ecc
2.5 KiB
GraphiteMergeTree
This engine is designed for rollup (thinning and aggregating/averaging) Graphite data. It may be helpful to developers who want to use ClickHouse as a data store for Graphite.
Graphite stores full data in ClickHouse, and data can be retrieved in the following ways:
-
Without thinning.
Uses the MergeTree engine.
-
With thinning.
Using the
GraphiteMergeTreeengine.
The engine inherits properties from MergeTree. The settings for thinning data are defined by the graphite_rollup parameter in the server configuration.
Using The Engine
The Graphite data table must contain the following fields at minimum:
Path– The metric name (Graphite sensor).Time– The time for measuring the metric.Value– The value of the metric at the time set in Time.Version– Determines which value of the metric with the same Path and Time will remain in the database.
Rollup pattern:
pattern
regexp
function
age -> precision
...
pattern
...
default
function
age -> precision
...
When processing a record, ClickHouse will check the rules in the patternclause. If the metric name matches the regexp, the rules from pattern are applied; otherwise, the rules from default are used.
Fields in the pattern.
age– The minimum age of the data in seconds.function– The name of the aggregating function to apply to data whose age falls within the range[age, age + precision].precision– How precisely to define the age of the data in seconds.regexp– A pattern for the metric name.
Example of settings:
<graphite_rollup>
<pattern>
<regexp>click_cost</regexp>
<function>any</function>
<retention>
<age>0</age>
<precision>5</precision>
</retention>
<retention>
<age>86400</age>
<precision>60</precision>
</retention>
</pattern>
<default>
<function>max</function>
<retention>
<age>0</age>
<precision>60</precision>
</retention>
<retention>
<age>3600</age>
<precision>300</precision>
</retention>
<retention>
<age>86400</age>
<precision>3600</precision>
</retention>
</default>
</graphite_rollup>