These docs are for Cribl Stream 4.15 and are no longer actively maintained.

See the latest version (4.20).

Cribl Stream supports receiving data over HTTP/S from Cribl Bulk API, Splunk HEC, and Elastic Bulk API endpoints.

Type: Push | TLS Support: YES | Event Breaker Support: No

This Source supports gzip-compressed inbound data when the Content-Encoding: gzip connection header is set.

Configure Cribl Stream to Receive Data over HTTP(S) ​

Cribl Stream ships with an HTTP Source preconfigured to listen on Port 10080, and on several default endpoints. You can clone or directly modify this Source to further configure it, and then enable it.

1. On the top bar, select Products, and then select Cribl Stream. Under Worker Groups, select a Worker Group. Next, you have two options:

   • To configure via QuickConnect, navigate to Routing > QuickConnect (Stream) or Collect (Edge). Select Add Source and select the Source you want from the list, choosing either Select Existing or Add New.
   • To configure via the Routes, select Data > Sources (Stream) or More > Sources (Edge). Select the Source you want. Next, select Add Source.

2. In the New Source modal, configure the following under General Settings:

   • Input ID: Enter a unique name. The default Source is prefilled with the value http, which can’t be changed via the UI. If you clone this Source, Cribl Stream will add -CLONE to the original Input ID.
   • Description: Optionally, enter a description.
   • Address: Enter the hostname/IP on which to listen for HTTP(S) data. (For example, localhost or 0.0.0.0.)
   • Port: Enter the port number to listen on.

3. Under Authentication, enter the Auth tokens:

   • Token: Shared secrets to be provided by any client (Authorization: <token>). Click Generate to create a new secret. If empty, unauthorized access will be permitted.
   • Description: Optionally, enter a description.
   • Fields: Fields to add to events referencing this token. Each field is a Name/Value pair, where Value is a JavaScript expression to compute field’s value, enclosed in quotes or backticks. (Can evaluate to a constant.) For details, see Authentication Fields.

4. Next, you can configure the following Optional Settings:

   • Cribl HTTP event API: Base path on which to listen for Cribl HTTP API requests. To construct the actual endpoint, Cribl Stream will append /_bulk to this path. For example, with the default value of /cribl, your senders should send events to a /cribl/_bulk path. Use an empty string to disable.
   • Elastic API endpoint (for Bulk API): Base path on which to listen for Elasticsearch API requests. For details, see Elastic API Endpiont.
   • Splunk HEC endpoint: Absolute path on which to listen for Splunk HTTP Event Collector (HEC) API requests. Use an empty string to disable. Default entry is /services/collector. For details, see Splunk HEC Endpoint.
   • Enable Splunk HEC acknowledgements: Whether to enable Splunk HEC acknowledgements. Default is toggled off.
   • Tags: Optionally, add tags that you can use to filter and group Sources in Cribl Stream’s UI. These tags aren’t added to processed events. Use a tab or hard return between (arbitrary) tag names.

5. Optionally, you can adjust the TLS, Persistent Queue Settings, Processing and Advanced settings, or Connected Destinations outlined in the sections below.

6. Select Save, then Commit & Deploy.

Elastic API Endpoint ​

Currently, the only supported option is the default /elastic, to which Cribl Stream will append /_bulk. So, your senders should send events to an /elastic/_bulk path. Other entries are faked as success. Use an empty string to disable.

Cribl generally recommends that you use the dedicated Elasticsearch API Source instead of this endpoint. The Elastic API implementation here is provided for backward compatibility, and for users who want to ingest multiple inputs on one HTTP/S port.

Splunk HEC Endpoint ​

This Splunk HEC implementation is an event (such as, not raw) endpoint. For details, see Splunk’s documentation. To send data to it from a HEC client, use either /services/collector or /services/collector/event. (See the examples below.)

The system default Event Breaker is automatically applied, which enforces a limit of 51,200 bytes per event.

Cribl generally recommends that you use the dedicated Splunk HEC Source instead of this endpoint. The Splunk HEC implementation here is provided for backward compatibility, and for users who want to ingest multiple inputs on one HTTP/S port.

Authentication Fields ​

By default, fields specified here will override fields of the same name in incoming events. However, you can customize this behavior to allow event fields to take precedence. For example, to allow the event’s index field to take precedence, you could use this expression: `event.index || 'defaultIndex'`.

Fields add context to events based on the token used. This can be useful for tagging events with metadata such as source or environment, enhancing security by avoiding direct use of authorization values in Routes and Pipelines.

See also Periodic Logging for information on how auth tokens affect product logging.

TLS Settings (Server Side) ​

Enabled: Defaults to toggled off. When toggled on:

Certificate: Name of the predefined certificate.

Private key path: Server path containing the private key (in PEM format) to use. Path can reference $ENV_VARS.

Passphrase: Passphrase to use to decrypt private key.

Certificate path: Server path containing certificates (in PEM format) to use. Path can reference $ENV_VARS.

CA certificate path: Server path containing CA certificates (in PEM format) to use. Path can reference $ENV_VARS.

Authenticate client (mutual auth): Require clients to present their certificates. Used to perform mutual authentication using SSL certs. Default is toggled off. When toggled on:

• Validate client certificates: Reject certificates that are not authorized by a CA in the CA certificate path, or by another trusted CA (for example, the system’s CA). Default is toggled on.

• Common name: Regex that a peer certificate’s subject attribute must match in order to connect. Defaults to .*. Matches on the substring after CN=. As needed, escape regex tokens to match literal characters. (For example, to match the subject CN=worker.cribl.local, you would enter: worker\.cribl\.local.) If the subject attribute contains Subject Alternative Name (SAN) entries, the Source will check the regex against all of those but ignore the Common Name (CN) entry (if any). If the certificate has no SAN extension, the Source will check the regex against the single name in the CN.

Minimum TLS version: Optionally, select the minimum TLS version to accept from connections.

Maximum TLS version: Optionally, select the maximum TLS version to accept from connections.

Persistent Queue Settings ​

In the Persistent Queue Settings tab, you can optionally specify persistent queue storage, using the following controls. Persistent queue buffers and preserves incoming events when a downstream Destination has an outage or experiences backpressure.

Before enabling persistent queue, learn more about persistent queue behavior and how to optimize it with your system:

• About Persistent Queues
• Optimize Source Persistent Queues (sPQ)

On Cribl-managed Cloud Workers (with an Enterprise plan), this tab exposes only the Enable persistent queue toggle. If enabled, PQ is automatically configured in Always On mode, with a maximum queue size of 1 GB disk space allocated per PQ-enabled Source, per Worker Process.

The 1 GB limit is on uncompressed inbound data, and the queue does not perform any compression. This limit is not configurable. For configurable queue size, compression, mode, and other options below, use a hybrid Group.

Enable persistent queue: Default is toggled off. When toggled on:

Mode: Select a condition for engaging persistent queues.

• Always On: This default option will always write events to the persistent queue, before forwarding them to the Cribl Stream data processing engine.
• Smart: This option will engage PQ only when the Source detects backpressure from the Cribl Stream data processing engine.

Smart mode only engages when necessary, such as when a downstream Destination becomes blocked and the Buffer size limit reaches its limit. When persistent queue is set to Smart mode, Cribl attempts to flush the queue when every new event arrives. The only time events stay in the buffer is when a downstream Destination becomes blocked.

Buffer size limit: The maximum number of events to hold in memory before reporting backpressure to the sender and writing the queue to disk. Defaults to 1000. This buffer is for all connections, not just per Worker Process. For that reason, this can dramatically expand memory usage. Connections share this limit, which may result in slightly lower throughput for higher numbers of connections. For higher numbers of connections, consider increasing the limit.

Commit frequency: The number of events to send downstream before committing that Stream has read them. Defaults to 42.

File size limit: The maximum data volume to store in each queue file before closing it and (optionally) applying the configured Compression. Enter a numeral with units of KB, MB, and so forth. If not specified, Cribl Stream applies the default 1 MB.

Queue size limit: The maximum amount of disk space that the queue is allowed to consume on each Worker Process. Once this limit is reached, this Source will stop queueing data and block incoming data. Required, and defaults to 5 GB. Accepts positive numbers with units of KB, MB, GB, and so forth. Can be set as high as 1 TB, unless you’ve configured a different Worker Process PQ size limit in Group or Fleet settings.

Queue file path: The location for the persistent queue files. Defaults to $CRIBL_HOME/state/queues. To this field’s specified path, Cribl Stream will append /<worker-id>/inputs/<input-id>.

Compression: Optional codec to compress the persisted data after a file closes. Defaults to None; Gzip is also available.

In Cribl Stream 4.1 and newer, the Source persistent queue default Mode is Always on, to best ensure events’ delivery. For details on optimizing this selection, see Optimize Source Persistent Queues (sPQ).

You can optimize Workers’ startup connections and CPU load at Group/Fleet settings > Worker Processes.

Processing Settings ​

Fields ​

In this section, you can define new fields or modify existing ones using JavaScript expressions, similar to the Eval function.

• The Field Name can either be a new field (unique within the event) or an existing field name to modify its value.
• The Value is a JavaScript expression (enclosed in quotes or backticks) to compute the field’s value (can be a constant). Select this field’s advanced mode icon (far right) if you’d like to open a modal where you can work with sample data and iterate on results.

This flexibility means you can:

• Add new fields to enrich the event.
• Modify existing fields by overwriting their values.