91 lines
4.2 KiB
Text
91 lines
4.2 KiB
Text
[role="xpack"]
|
||
[[correlations]]
|
||
=== Find latency and error correlations
|
||
|
||
**Correlations** surface attributes of your data that are potentially correlated with high-latency or erroneous transactions.
|
||
Surfaced attributes are user-defined, meaning that they are completely customizable to your APM data.
|
||
Find something interesting? A quick click of a button will auto-query your data as you work to resolve the underlying issue.
|
||
|
||
For example, a site reliability engineer, who is responsible for keeping production systems up and running,
|
||
notices an increase in latency in certain transactions.
|
||
Analyzing metadata or tags that exist in high-latency transactions but not in lower-latency transactions
|
||
can potentially point towards the root cause.
|
||
They may find that a particular piece of hardware, like a host or pod, has failed, increasing latency.
|
||
Or, perhaps a set of users, based on IP address or region, is physically too far away from the nearest
|
||
data center, increasing latency.
|
||
|
||
[discrete]
|
||
[[view-correlations]]
|
||
=== View correlations
|
||
|
||
With a service selected, click **View correlations**:
|
||
|
||
[role="screenshot"]
|
||
image::apm/images/correlations.png[Correlations]
|
||
|
||
Queries within the APM app apply to the correlations shown in the correlations fly-out.
|
||
|
||
If a correlated field seems noteworthy, use the **Filter** quick links:
|
||
|
||
* `+` creates a new query in the APM app for transactions containing the selected value.
|
||
* `-` creates a new query in the APM app for transactions without the selected value.
|
||
|
||
[discrete]
|
||
[[correlations-latency]]
|
||
==== Find high-latency correlations
|
||
|
||
Correlations help you discover which fields are contributing to increased service latency.
|
||
|
||
A latency distribution chart visualizes the overall latency of the selected service's transactions.
|
||
Correlated attributes are sorted by _Impact_–a visual representation of the score for the underlying
|
||
aggregation that powers correlations.
|
||
Attributes with a high impact, or attributes present in a large percentage of slow transactions,
|
||
may contribute to increased latency.
|
||
|
||
To find high-latency correlations, hover over each potentially correlated attribute to
|
||
compare the latency distribution of transactions with and without the selected attribute.
|
||
|
||
For example, in the screenshot below, the field `user_agent.name` and value `HeadlessChrome`
|
||
exists primarily in higher-latency transactions between 3.7 and 8.7 seconds.
|
||
|
||
[role="screenshot"]
|
||
image::apm/images/correlations-hover.png[Correlations hover effect]
|
||
|
||
Selecting the `+` filter creates a new query in the APM app for transactions with
|
||
`user_agent.name: HeadlessChrome`. With the "noise" now filtered out,
|
||
you can begin viewing sample traces to continue your investigation.
|
||
|
||
[discrete]
|
||
[[correlations-error-rate]]
|
||
==== Find error rate correlations
|
||
|
||
Correlations help you discover which fields are contributing to failed transactions.
|
||
|
||
The Error rate over time chart visualizes the change in error rate over the selected time frame.
|
||
Correlated attributes are sorted by _Impact_–a visual representation of the score for the underlying
|
||
aggregation that powers correlations.
|
||
Attributes with a high impact, or attributes present in a large percentage of failed transactions,
|
||
may contribute to increased error rates.
|
||
|
||
To find error rate correlations, hover over each potentially correlated attribute to
|
||
compare the error rate distribution of transactions with and without the selected attribute.
|
||
|
||
For example, in the screenshot below, the field `url.original` and value `http://localhost:3100...`
|
||
existed in 100% of failed transactions between 6:00 and 10:30.
|
||
|
||
[role="screenshot"]
|
||
image::apm/images/error-rate-hover.png[Correlations errors hover effect]
|
||
|
||
Selecting the `+` filter creates a new query in the APM app for transactions with
|
||
`url.original: http://localhost:3100...`. With the "noise" now filtered out,
|
||
you can begin viewing sample traces to continue your investigation.
|
||
|
||
[discrete]
|
||
[[correlations-custom-fields]]
|
||
==== Customize fields
|
||
|
||
Correlations are only as good as the data they're searching for.
|
||
By default, a handful of potentially useful fields are selected, like `lables`, `service.version`, and `host.ip`.
|
||
You can remove and add fields to this list under the **Customize fields** dropdown.
|
||
|
||
TIP: Want to start over? Select **reset** to clear your customizations.
|