SPLK-1002 — Frequently Asked Questions

To filter events by a tag, you use the tag keyword in your search. The syntax is tag=<tag_name>. For example, to find all events tagged as 'webserver', you would use the search tag=webserver. You can also combine tags, such as tag=webserver tag=error.

The . (dot) operator is used for string concatenation in the eval command. If you are concatenating a string with a number, Splunk automatically converts the number to a string. For example: | eval new_field = string_field . number_field.

The best method is using a regular expression (regex). You can use the Field Extractor (FX) wizard and select 'Regular Expression'. A suitable regex to capture the port number after a colon would be :(?<port>\d+). This creates a new field named 'port' containing the digits.

To pass an argument to a nested macro, you include the inner macro call with its argument inside the outer macro call. The syntax is !outer_macro_name(!inner_macro_name(argument_value)!)!. The arguments are resolved from the inside out.

Editing the regex for a field extraction will change how the field is extracted from all future events that match the source type. It does not re-index or re-process historical data; the change only applies to new data coming in after the modification is saved.

A POST workflow action is specifically designed to send event data to an external web resource using the HTTP POST method. This is useful for triggering actions in other systems, as it can send field values from the event in the body of the POST request.

An event type definition consists of a search string. This string can include search terms, fields, tags, and boolean expressions (like AND, OR, NOT). It defines a reusable search that categorizes a set of events. It cannot contain generating commands like search or from at the beginning.

If a field alias is created with the same name as an existing extracted field and the 'overwrite' option is selected, the alias will take precedence. The original field's values will be hidden and replaced by the values from the field that the alias points to.

The eval command is a transforming command. It is used to calculate an expression and put the results into a new or existing field. It operates on the results of the search so far and is often used for calculations, string manipulation, and conditional logic.

To edit an accelerated data model, you must first disable its acceleration. Navigate to the Data Models page in the Settings menu, find the data model, and turn off acceleration. After making your edits to the data model structure, you can then re-enable acceleration, which will require Splunk to rebuild the summary index.

The coalesce function returns the value of the first non-null field in the list of arguments provided. For example, in | eval result = coalesce(field1, field2, field3), if field1 has a value, that value is returned. If field1 is null, it checks field2, and so on.

Field aliases can be used by most knowledge objects that operate on search results. This includes searches, saved searches, alerts, dashboards, and reports. Once an alias is defined, it can be used in SPL just like any other field name.

If a calculated field has the same name as an existing extracted field, the calculated field's value will overwrite the extracted field's value. Calculated fields are applied after field extractions, so they take precedence in case of a naming conflict.

In a macro definition, arguments are represented by a dollar sign followed by the argument number. The syntax is $1$ for the first argument, $2$ for the second, and so on. When the macro is used, these placeholders are replaced by the values passed to it.

A field alias is applied to a specific source type. When you create a field alias, you define the original field name, the alias, and the app and source type to which it applies. This ensures the alias is only created for events from that specific source type.