Graphite Tag Support
With the release of the 1.1.x series, Graphite now supports tagged metrics.
Rather than using the traditional dotted hierarchy, metrics can be stored and retrieved based on tags - for example, host=webserver- or region=us-east-1.
So where before you might have a name like myapp.webserver-0001.us-east-1.responses.500, you could instead have myapp.responses;host=webserver-0001;region=us-east-1;code=500
It’s becoming common in monitoring systems to use a tagged (or labeled) metric format. This allows for more flexibility both in naming and retrieving metrics. Tags also allow you to categorize metrics based on various dimensions or attributes enabling you to filter and aggregate data in ways that make sense for your analysis.
Note that when using tags, each metric is uniquely identified by its name and set of tag/value pairs. As a result, an existing tagged metric cannot be updated to contain new tags.
For example, let’s count 500 responses for My App in both formats:
Dotted Format
Order matters
Can have many node options which can be unwieldy
Tag Format
Order does not matter
You do not always need every node in the metric name to locate one metric or series
Does not support wildcards, but accepts regular expressions
The latter allows us to quickly slice and dice metrics by their tags that you get to specify when creating the metric. We don’t have to remember what’s in each position in the dotted hierarchy, and the tags make the query “self documenting”.
Tags are particularly useful in modern cloud environments, where e.g. host or instance may change often, while the total number of metrics being stored and queried remains fairly constant.
You can use the same Carbon endpoints you already use to send tagged metrics. All you need to do is include the tags and values in the updated Carbon line protocol format (unix timestamp is optional):
E.g. to get started quickly you can use the netcat utility as follows:
Sending metrics in your favorite language is similar. Refer to our language guide.
You can query metrics by their tag values, or by the metric name but all queries must be wrapped with a seriesByTag() graphite function. You can do this in your dashboards by toggling the query box to free-text-mode and typing out the full query. Or you could begin by adding the seriesByTag() function and filling the boxes with your search terms using the expressions (see table below) where necessary.
You can also search for tagged metrics in the HG Tag Search UI, and use the Explore feature to open dashboard panels with pre-formatted queries.
You can use any number of tag expressions to filter through your metrics:
Other graphite functions also work, such as sumSeries in the below example:
For a full list of Graphite functions and how to use them, check out the Graphite Function Docs.
seriesByTag() supports any number of tag expressions to refine the results. If using multiple expressions, only series that match all of them will be returned. Expressions have the following formats:
tag!=spec
tag value does not exactly match the spec
tag=~spec
tag value matches the regular expression spec
tag!=~spec
tag value does not match the regular expression spec
tag=spec
tag value exactly matches the spec
Example:
Find all series where server matches the regular expression 0\.* and env is not staging
These are the ‘tagged’ equivalent of the aliasByNodes() and groupByNodes() Graphite functions.
aliasByTags requires at least one tag name to be passed in, below we have three:
groupByTags requires an aggregation method to be passed in (e.g. min, max, avg, sum, etc.), below we use sum:
For more information about querying tagged metrics refer to the Graphite Tag Docs
You can easily locate and delete your tagged metrics from within our Tag Search feature. Just select a tag name, search for a value, and a list of matching metrics will be rendered with the option to view or delete any selected metrics.
We also offer a Tag Expiry feature that will automatically delete tagged metrics after a defined period of inactivity:
Check out our tag API documentation here.
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