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[DOCS] Updates categorization examples with wizard screenshots (#51133)
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[role="xpack"]
[[ml-configuring-categories]]
=== Categorizing data
=== Detecting anomalous categories of data

Categorization is a {ml} process that considers a tokenization of a field,
clusters similar data together, and classifies them into categories. However,
categorization doesn't work equally well on different data types. It works
best on machine-written messages and application outputs, typically on data that
consists of repeated elements, for example log messages for the purpose of
system troubleshooting. Log categorization groups unstructured log messages into
categories, then you can use {anomaly-detect} to model and identify rare or
unusual counts of log message categories.
Categorization is a {ml} process that tokenizes a text field, clusters similar
data together, and classifies it into categories. It works best on
machine-written messages and application output that typically consist of
repeated elements. For example, it works well on logs that contain a finite set
of possible messages:

Categorization is tuned to work best on data like log messages by taking token
order into account, not considering synonyms, and including stop words in its
analysis. Complete sentences in human communication or literary text (for
example emails, wiki pages, prose, or other human generated content) can be
extremely diverse in structure. Since categorization is tuned for machine data
it will give poor results on such human generated data. For example, the
categorization job would create so many categories that couldn't be handled
effectively. Categorization is _not_ natural language processing (NLP).

[float]
[[ml-categorization-log-messages]]
==== Categorizing log messages

Application log events are often unstructured and contain variable data. For
example:
//Obtained from it_ops_new_app_logs.json
[source,js]
----------------------------------
{"time":1454516381000,"message":"org.jdbi.v2.exceptions.UnableToExecuteStatementException: com.mysql.jdbc.exceptions.MySQLTimeoutException: Statement cancelled due to timeout or client request [statement:\"SELECT id, customer_id, name, force_disabled, enabled FROM customers\"]","type":"logs"}
{"@timestamp":1549596476000,
"message":"org.jdbi.v2.exceptions.UnableToExecuteStatementException: com.mysql.jdbc.exceptions.MySQLTimeoutException: Statement cancelled due to timeout or client request [statement:\"SELECT id, customer_id, name, force_disabled, enabled FROM customers\"]",
"type":"logs"}
----------------------------------
//NOTCONSOLE

You can use {ml} to observe the static parts of the message, cluster similar
messages together, and classify them into message categories.
Categorization is tuned to work best on data like log messages by taking token
order into account, including stop words, and not considering synonyms in its
analysis. Complete sentences in human communication or literary text (for
example email, wiki pages, prose, or other human-generated content) can be
extremely diverse in structure. Since categorization is tuned for machine data,
it gives poor results for human-generated data. It would create so many
categories that they couldn't be handled effectively. Categorization is _not_
natural language processing (NLP).

When you create a categorization {anomaly-job}, the {ml} model learns what
volume and pattern is normal for each category over time. You can then detect
anomalies and surface rare events or unusual types of messages by using
<<ml-count-functions,count>> or <<ml-rare-functions,rare>> functions.

In {kib}, there is a categorization wizard to help you create this type of
{anomaly-job}. For example, the following job generates categories from the
contents of the `message` field and uses the count function to determine when
certain categories are occurring at anomalous rates:

The {ml} model learns what volume and pattern is normal for each category over
time. You can then detect anomalies and surface rare events or unusual types of
messages by using count or rare functions. For example:
[role="screenshot"]
image::images/ml-category-wizard.jpg["Creating a categorization job in Kibana"]

//Obtained from it_ops_new_app_logs.sh
[%collapsible]
.API example
====
[source,console]
----------------------------------
PUT _ml/anomaly_detectors/it_ops_new_logs
PUT _ml/anomaly_detectors/it_ops_app_logs
{
"description" : "IT Ops Application Logs",
"description" : "IT ops application logs",
"analysis_config" : {
"categorization_field_name": "message", <1>
"categorization_field_name": "message",<1>
"bucket_span":"30m",
"detectors" :[{
"function":"count",
"by_field_name": "mlcategory", <2>
"detector_description": "Unusual message counts"
}],
"categorization_filters":[ "\\[statement:.*\\]"]
},
"analysis_limits":{
"categorization_examples_limit": 5
"by_field_name": "mlcategory"<2>
}]
},
"data_description" : {
"time_field":"time",
"time_format": "epoch_ms"
"time_field":"@timestamp"
}
}
----------------------------------
// TEST[skip:needs-licence]

<1> The `categorization_field_name` property indicates which field will be
categorized.
<2> The resulting categories are used in a detector by setting `by_field_name`,
<1> This field is used to derive categories.
<2> The categories are used in a detector by setting `by_field_name`,
`over_field_name`, or `partition_field_name` to the keyword `mlcategory`. If you
do not specify this keyword in one of those properties, the API request fails.
====

The optional `categorization_examples_limit` property specifies the
maximum number of examples that are stored in memory and in the results data
store for each category. The default value is `4`. Note that this setting does
not affect the categorization; it just affects the list of visible examples. If
you increase this value, more examples are available, but you must have more
storage available. If you set this value to `0`, no examples are stored.

The optional `categorization_filters` property can contain an array of regular
expressions. If a categorization field value matches the regular expression, the
portion of the field that is matched is not taken into consideration when
defining categories. The categorization filters are applied in the order they
are listed in the job configuration, which allows you to disregard multiple
sections of the categorization field value. In this example, we have decided that
we do not want the detailed SQL to be considered in the message categorization.
This particular categorization filter removes the SQL statement from the
categorization algorithm.

If your data is stored in {es}, you can create an advanced {anomaly-job} with
these same properties:
You can use the **Anomaly Explorer** in {kib} to view the analysis results:

[role="screenshot"]
image::images/ml-category-advanced.jpg["Advanced job configuration options related to categorization"]

NOTE: To add the `categorization_examples_limit` property, you must use the
**Edit JSON** tab and copy the `analysis_limits` object from the API example.

[float]
image::images/ml-category-anomalies.jpg["Categorization results in the Anomaly Explorer"]

For this type of job, the results contain extra information for each anomaly:
the name of the category (for example, `mlcategory 2`) and examples of the
messages in that category. You can use these details to investigate occurrences
of unusually high message counts.

If you use the advanced {anomaly-job} wizard in {kib} or the
{ref}/ml-put-job.html[create {anomaly-jobs} API], there are additional
configuration options. For example, the optional `categorization_examples_limit`
property specifies the maximum number of examples that are stored in memory and
in the results data store for each category. The default value is `4`. Note that
this setting does not affect the categorization; it just affects the list of
visible examples. If you increase this value, more examples are available, but
you must have more storage available. If you set this value to `0`, no examples
are stored.

Another advanced option is the `categorization_filters` property, which can
contain an array of regular expressions. If a categorization field value matches
the regular expression, the portion of the field that is matched is not taken
into consideration when defining categories. The categorization filters are
applied in the order they are listed in the job configuration, which enables you
to disregard multiple sections of the categorization field value. In this
example, you might create a filter like `[ "\\[statement:.*\\]"]` to remove the
SQL statement from the categorization algorithm.

[discrete]
[[ml-configuring-analyzer]]
===== Customizing the categorization analyzer
==== Customizing the categorization analyzer

Categorization uses English dictionary words to identify log message categories.
By default, it also uses English tokenization rules. For this reason, if you use
the default categorization analyzer, only English language log messages are
supported, as described in the <<ml-limitations>>.
supported, as described in the <<ml-limitations>>.

You can, however, change the tokenization rules by customizing the way the
categorization field values are interpreted. For example:
If you use the categorization wizard in {kib}, you can see which categorization
analyzer it uses and highlighted examples of the tokens that it identifies. You
can also change the tokenization rules by customizing the way the categorization
field values are interpreted:

[source,console]
----------------------------------
PUT _ml/anomaly_detectors/it_ops_new_logs2
{
"description" : "IT Ops Application Logs",
"analysis_config" : {
"categorization_field_name": "message",
"bucket_span":"30m",
"detectors" :[{
"function":"count",
"by_field_name": "mlcategory",
"detector_description": "Unusual message counts"
}],
"categorization_analyzer":{
"char_filter": [
{ "type": "pattern_replace", "pattern": "\\[statement:.*\\]" } <1>
],
"tokenizer": "ml_classic", <2>
"filter": [
{ "type" : "stop", "stopwords": [
"Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday",
"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun",
"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December",
"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
"GMT", "UTC"
] } <3>
]
}
},
"analysis_limits":{
"categorization_examples_limit": 5
},
"data_description" : {
"time_field":"time",
"time_format": "epoch_ms"
}
}
----------------------------------
// TEST[skip:needs-licence]
[role="screenshot"]
image::images/ml-category-analyzer.jpg["Editing the categorization analyzer in Kibana"]

<1> The
The categorization analyzer can refer to a built-in {es} analyzer or a
combination of zero or more character filters, a tokenizer, and zero or more
token filters. In this example, adding a
{ref}/analysis-pattern-replace-charfilter.html[`pattern_replace` character filter]
here achieves exactly the same as the `categorization_filters` in the first
example.
<2> The `ml_classic` tokenizer works like the non-customizable tokenization
that was used for categorization in older versions of machine learning. If you
want the same categorization behavior as older versions, use this property
value.
<3> By default, English day or month words are filtered from log messages before
categorization. If your logs are in a different language and contain
dates, you might get better results by filtering the day or month words in your
language.
achieves exactly the same behavior as the `categorization_filters` job
configuration option described earlier. For more details about these properties,
see the
{ref}/ml-put-job.html#ml-put-job-request-body[`categorization_analyzer` API object].

The optional `categorization_analyzer` property allows even greater customization
of how categorization interprets the categorization field value. It can refer to
a built-in {es} analyzer or a combination of zero or more character filters,
a tokenizer, and zero or more token filters. If you omit the
`categorization_analyzer`, the following default values are used:
If you use the default categorization analyzer in {kib} or omit the
`categorization_analyzer` property from the API, the following default values
are used:

[source,console]
--------------------------------------------------
Expand Down Expand Up @@ -279,23 +236,3 @@ categorization analyzer produces must be similar to those produced by the search
analyzer. If they are sufficiently similar, when you search for the tokens that
the categorization analyzer produces then you find the original document that
the categorization field value came from.

NOTE: To add the `categorization_analyzer` property in {kib}, you must use the
**Edit JSON** tab and copy the `categorization_analyzer` object from one of the
API examples above.

[float]
[[ml-viewing-categories]]
===== Viewing categorization results

After you open the job and start the {dfeed} or supply data to the job, you can
view the categorization results in {kib}. For example:

[role="screenshot"]
image::images/ml-category-anomalies.jpg["Categorization example in the Anomaly Explorer"]

For this type of job, the **Anomaly Explorer** contains extra information for
each anomaly: the name of the category (for example, `mlcategory 11`) and
examples of the messages in that category. In this case, you can use these
details to investigate occurrences of unusually high message counts for specific
message categories.
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