Collect custom records

You can customize the type of record details you generate and store on a recordstore by writing a trigger. We recommend that you also create a record format to control how the records display in the ExtraHop system.

Before you begin

  • These instructions assume some familiarity with ExtraHop Triggers.
  • If you are connected to a Google BigQuery recordstore, there is a custom records field limit of 300.

In the following example, you will learn how to only store records for HTTP transactions that results in a 404 status code. First, we will write a trigger to collect information from the built-in HTTP record type. Then, we will assign the trigger to a web server. Finally, we will create a record format to display selected record fields in the table view for our record query results.

Write and assign a trigger

Note that the trigger must be created on each sensor that you want to collect these types of records from. You can create the trigger on a console to collect your custom records from all connected sensors.

  1. Log in to the ExtraHop system through https://<extrahop-hostname-or-IP-address>.
  2. Click the System Settings icon , and then click Triggers.
  3. Click Create.
  4. In the Create Trigger pane, complete your information, similar to the following example:

    Name: HTTP 404 Errors

    Description: Track 404 errors on primary web server.

    Enable debug log: Select the checkbox to enable debugging.


  5. Click the Editor tab to write the trigger specifications.
    The following figure shows an example configuration that only collects records when a 404 status code is detected. We also set a name (web404) for these types of records to identify them in a record query and added identifying information for debugging.

    In the next steps, assign the trigger to a device or device group for which you want to monitor 404 status codes.
  6. Click Assets from the top menu.
  7. Click Devices and then click the Active Devices chart.
  8. Select the checkbox for a device from the list. For our example, we will select a web server called web2-sea.
  9. Click the Assign Triggers icon, select the trigger you created in the previous steps, and then click Assign Triggers. In the following figure, we have selected our web server, web2-sea.
    After assigning the trigger, return to the System Settings > Trigger page and select the trigger you created. First, make sure your device has activity. Then, click the Debug Log tab to see if the trigger is committing your records. For the following example, we intentionally visited unavailable web pages to generate 404 errors.

Create a custom record format to display your record results in a table

Record formats are the recommended way to display your records with only the fields you want to see. Without a custom record format, the fields for your custom record will not appear in any selectable lists, such as the Group By list.

The quickest way to create a custom record format is to copy and paste the schema on read from a built-in record format into a new record format. If you have multiple sensors, you need to create the custom record format on each appliance where the record results are viewed. You can create the record format on a console to format a custom record on all connected sensors.
  1. Log in to the ExtraHop system through https://<extrahop-hostname-or-IP-address>.
  2. Click the System Settings icon and then click Record Formats.
  3. Click on the type of record you want to copy. For our example, we will copy the HTTP record format.
  4. Copy the contents in the text box below Schema on Read.
  5. Click New Record Format.
  6. Complete the following fields:

    Display Name: Type a unique name for your record format.

    Author: Identify the author for the record format.

    Record Type: Type the same record type ID you created in the trigger. In our example, this value is web404.

    Schema on Read: Paste the copied contents from step 4 into the text box. Edit the box to delete any unwanted fields. For our example in the figure below, we only kept the following fields: Client, Server, Method, Status Code, URI, and Processing Time.

Query for your custom record type

  1. Click Records from the top menu.
  2. Click the Any Record Type drop-down list and select your newly created record format.
  3. Click View Records.
  4. Click the Verbose View icon.
  5. Click Fields and then click Select All.
    All of the information collected from the trigger about these records is shown in the query results.

Record format settings

The Record Format Settings page displays a list of all built-in and custom record formats that are available on your ExtraHop sensors or console. If you need to create a custom record format, we recommend that you copy and paste the schema on read information from a built-in record format. Advanced users might want to create a custom record format with their own field-value pairs, and should apply the reference material provided in this section.

Record formats consist of the following settings:
Display Name
The name displayed for the record format in the ExtraHop system. If there is no record format for the record, the record type is displayed.
(Optional) The author of the record format. All built-in record formats display ExtraHop as the author.
Record Type
A unique alphanumeric name that identifies the type of information contained in the associated record format. The record type links the record format with the records that are sent to the recordstore. Built-in record formats have a record type that begins with a tilde (~). Custom record formats cannot have a record type that begins with a tilde (~) or an at symbol (@).
Schema on Read
A JSON-formatted array with at least one object, which consists of a field name and value pair. Each object describes a field in the record and each object must have a unique combination of name and data type for that record format. You can create the following objects for a custom record format:
The name of the field.
The display name for the field. If the display_name field is empty, the name field is displayed.
(Optional) Descriptive information about the record format. This field is limited to the Record Format Settings page and is not displayed in any record query.
(Optional) If set to true, this field displays in the ExtraHop system as a column heading by default in table view.
(Optional) If set to true, facets for this field display in the ExtraHop system. Facets are a short list of the most common values for the field that can be clicked to add a filter.
The abbreviation that identifies the type of data stored in this field. The following data types are supported:
Data Type Abbreviation Description
application app ExtraHop application ID (string)
boolean b Boolean value
device dev ExtraHop device ID (string)
flow interface fint Flow interface ID
flow network fnet Flow network ID
IPv4 addr4 An IPv4 address in dotted-quad format. Greater or less than filters are supported.
IPv6 addr6 An IPv6 address. Only string-oriented filters are supported.
number n Number (integer or floating point)
string s Generic string
The sub-classification of the data type that further determines how the information is displayed in the ExtraHop system. The following meta-types are supported for each of the associated data types:
Data Type Meta Type
  • domain
  • uri
  • user
  • bytes
  • count
  • expiration
  • milliseconds
  • packets
  • timestamp
Last modified 2024-04-02