These docs are for Cribl Edge 4.7 and are no longer actively maintained.

See the latest version (4.13).

Cribl HTTP Destination

The Cribl HTTP Destination sends data to a Cribl HTTP Source connected to the same Leader. Relaying data between a Cribl HTTP Destination and Cribl HTTP Source pair prevents double-billing: You’ll be charged no additional charges or credits after initial ingest to the first Fleet.

It’s common to send data from Cribl Edge to a Cribl Stream Worker Group using this kind of pairing.

Type: Streaming | TLS Support: Configurable | PQ Support: Yes

For guidance on when to choose this Source versus the Cribl TCP Destination, see Interoperation Protocols.

Within Cribl Stream, the Cribl HTTP Destination is available only in Distributed deployments. In single‑instance mode, or for testing, you can use the Webhook Destination instead. However, this substitution will not facilitate sending all internal fields, as described below.

How It Works

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You can use the Cribl HTTP Destination to transfer data between Edge Nodes and Workers. If the Cribl HTTP Destination sends data to its Cribl HTTP Source counterpart on another Worker, you’re billed for ingress only once – when Cribl first receives the data. All data subsequently relayed to other Workers via a Cribl HTTP Destination/Source pair is not charged.

This use case is common in hybrid Cribl.Cloud deployments, where a customer-managed (on-prem) Node sends data to a Worker in Cribl.Cloud for additional processing and routing to Destinations. However, the Cribl HTTP Destination/Source pair can similarly reduce your metered data ingress in other scenarios, such as on-prem Edge to on-prem Stream.

As one usage example, assume that you want to send data from one Node deployed on-prem, to another that is deployed in Cribl.Cloud. You could do the following:

• Create an on-prem File System Collector (or whatever Collector or Source is suitable) for the data you want to send to Cribl.Cloud.
• Create an on-prem Cribl HTTP Destination.
• Create a Cribl HTTP Source, on the target Stream Worker Group or Edge Fleet in Cribl.Cloud.
• For an on-prem Node configure a File System Collector to send data to the Cribl HTTP Destination, and from there to the Cribl HTTP Source in Cribl.Cloud.
• On Cribl-managed Cribl.Cloud Nodes, make sure that TLS is either disabled on both the Cribl HTTP Destination and the Cribl HTTP Source it’s sending data to, or enabled on both. Otherwise, no data will flow. On Cribl.Cloud instances, the Cribl HTTP Source ships with TLS enabled by default.

Configuration Requirements

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The key points about configuring this architecture are:

• The Cribl HTTP Destination must be on a Node that is connected to the same Leader as the Cribl HTTP Source(s).
• This Destination’s Cribl endpoint field must point to the Address and Port you’ve configured on its peer Cribl HTTP Source(s).
• Cribl 3.5.4 was a breakpoint in Cribl HTTP Leader/Worker communications. Nodes running the Cribl HTTP Destination on Cribl 3.5.4 and later can receive data only from Nodes running v.3.5.4 and later. Nodes running the Cribl HTTP Destination on Cribl 3.5.3 and earlier can receive data only from Nodes running v.3.5.3 and earlier.

Configuring a Cribl HTTP Destination

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From the top nav, click Manage, then select a Fleet to configure. Next, you have two options:

To configure via the graphical QuickConnect UI, click Routing > QuickConnect (Stream) or Collect (Edge). Next, click Add Destination at right. From the resulting drawer’s tiles, select Cribl HTTP. Next, click either Add Destination or (if displayed) Select Existing. The resulting drawer will provide the options below.

Or, to configure via the Routing UI, click Data > Destinations (Stream) or More > Destinations (Edge). From the resulting page’s tiles or the Destinations left nav, select Cribl HTTP. Next, click Add Destination to open a New Destination modal that provides the options below.

General Settings

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Output ID: Enter a unique name to identify this Destination definition. If you clone this Destination, Cribl Edge will add -CLONE to the original Output ID.

Load balancing: Set to No by default. When toggled to Yes, see Load Balancing Settings below. With the default No setting, if you notice that Cribl Edge is not sending data to all possible IP addresses, enable Advanced Settings > Round-robin DNS.

Cribl endpoint: URL of a Cribl Worker to send events to, e.g., http://localhost:10200.

The Cribl endpoint field appears only when Load balancing is toggled to Off. Its value must point to the Address and Port you’ve configured on the peer Cribl HTTP Source to which you’re sending.

Optional Settings

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Compression: Codec to use to compress the data before sending. Defaults to Gzip.

Backpressure behavior: Specifies whether to block, drop, or queue events when all receivers are exerting backpressure. Defaults to Block. See Persistent Queue Settings below.

Tags: Optionally, add tags that you can use to filter and group Destinations in Cribl Edge’s Manage Destinations page. These tags aren’t added to processed events. Use a tab or hard return between (arbitrary) tag names.

Load Balancing Settings

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Enabling the Load balancing toggle displays the following controls.

Exclude Current Host IPs: This toggle determines whether to exclude all IPs of the current host from the list of any resolved hostnames. Defaults to No, which keeps the current host available for load balancing.

Cribl Worker Endpoints: In this table, you specify a set of Cribl Workers on which to load-balance data. To specify more Workers on new rows, click Add Endpoint. Each row provides the following fields.

• Cribl Endpoint: Enter the URL of a Worker to send events to.

  Must point to the Address and Port configured on a peer Cribl HTTP Source to which you’re sending.

• Load weight: Set the relative traffic-handling capability for each connection by assigning a weight (> 0). This column accepts arbitrary values, but for best results, assign weights in the same order of magnitude to all connections. Cribl Edge will attempt to distribute traffic to the connections according to their relative weights.

• The final column provides an X button to delete any row from the table.

For details on configuring all these options, see About Load Balancing.

TLS Settings (Client Side)

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Use TLS defaults to No. When toggled to Yes:

Autofill?: This setting is experimental.

Validate server certs: Reject certificates that are not authorized by a CA in the CA certificate path, or by another trusted CA (e.g., the system’s CA). Defaults to Yes. Overrides the Validate server certs setting in Advanced Settings.

Server name (SNI): Server name for the SNI (Server Name Indication) TLS extension. This must be a host name, not an IP address.

Minimum TLS version: Optionally, select the minimum TLS version to use when connecting.

Maximum TLS version: Optionally, select the maximum TLS version to use when connecting.

Certificate name: The name of the predefined certificate.

CA certificate path: Path on client containing CA certificates (in PEM format) to use to verify the server’s cert. Path can reference $ENV_VARS.

Private key path (mutual auth): Path on client containing the private key (in PEM format) to use. Path can reference $ENV_VARS. Use only if mutual auth is required.

Certificate path (mutual auth): Path on client containing certificates in (PEM format) to use. Path can reference $ENV_VARS. Use only if mutual auth is required.

Passphrase: Passphrase to use to decrypt private key.

Persistent Queue Settings

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This section displays when the Backpressure behavior is set to Persistent Queue.

Max file size: The maximum data volume to store in each queue file before closing it. Enter a numeral with units of KB, MB, etc. Defaults to 1 MB.

Max queue size: The maximum amount of disk space the queue is allowed to consume. Once this limit is reached, Cribl Stream stops queueing and applies the fallback Queue‑full behavior. Enter a numeral with units of KB, MB, etc.

Queue file path: The location for the persistent queue files. Defaults to $CRIBL_HOME/state/queues. To this value, Cribl Stream will append /<worker‑id>/<output‑id>.

Compression: Codec to use to compress the persisted data, once a file is closed. Defaults to None; Gzip is also available.

Queue-full behavior: Whether to block or drop events when the queue is exerting backpressure (because disk is low or at full capacity). Block is the same behavior as non-PQ blocking, corresponding to the Block option on the Backpressure behavior drop-down. Drop new data throws away incoming data, while leaving the contents of the PQ unchanged.

Clear persistent queue: Click this button if you want to flush out files that are currently queued for delivery to this Destination. A confirmation modal will appear. (Appears only after Output ID has been defined.)

Processing Settings

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Post‑Processing

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Pipeline: Pipeline to process data before sending the data out using this output.

System fields: A list of fields to automatically add to events that use this output. By default, includes cribl_pipe (identifying the Cribl Stream Pipeline that processed the event). Supports wildcards. Other options include:

• cribl_host – Cribl Edge Node that processed the event.
• cribl_input – Cribl Edge Source that processed the event.
• cribl_output – Cribl Edge Destination that processed the event.
• cribl_route – Cribl Edge Route (or QuickConnect) that processed the event.
• cribl_wp – Cribl Edge Worker Process that processed the event.

Retries

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Honor Retry-After header: Whether to honor a Retry-After header, provided that the header specifies a delay no longer than 180 seconds. Cribl Stream/Edge limits the delay to 180 seconds even if the Retry-After header specifies a longer delay. When enabled, any Retry-After header received takes precedence over all other options configured in the Retries section. When disabled, all Retry-After headers are ignored.

Settings for failed HTTP requests: When you want to automatically retry requests that receive particular HTTP response status codes, use these settings to list those response codes.

For any HTTP response status codes that are not explicitly configured for retries, Cribl Stream/Edge applies the following rules:

Upon receiving a response code that’s on the list, Cribl Stream/Edge first waits for a set time interval called the Pre-backoff interval and then begins retrying the request. Time between retries increases based on an exponential backoff algorithm whose base is the Backoff multiplier, until the backoff multiplier reaches the Backoff limit (ms). At that point, Cribl Stream/Edge continues retrying the request without increasing the time between retries any further.

If the sender (which manages the connection to the Destination) is at capacity, it will not accept any incoming events. These incoming events originate internally from a previous stage of the data flow when Destinations send outbound requests to their respective external services, and they include retry requests and new requests. Any events that were already in transit when the sender reached capacity will continue to be processed downstream.

Sender capacity is freed up when an outgoing request succeeds or encounters a non-retryable error. When the sender has available capacity again, it will resume accepting incoming events. This capacity management is influenced by the number of active connections and configured limits, such as concurrency and buffer sizes. If a Pipeline sends events faster than the Destination can process, the buffers may fill up, leading to backpressure and Sender at capacity warnings. This backpressure prevents the sender from accepting additional requests until capacity is restored.

By default, this Destination has no response codes configured for automatic retries. For each response code you want to add to the list, select Add Setting and configure the following settings:

• HTTP status code: A response code that indicates a failed request, for example 429 (Too Many Requests) or 503 (Service Unavailable).
• Pre-backoff interval (ms): The amount of time to wait before beginning retries, in milliseconds. Defaults to 1000 (one second).
• Backoff multiplier: The base for the exponential backoff algorithm. A value of 2 (the default) means that Cribl Stream/Edge will retry after 2 seconds, then 4 seconds, then 8 seconds, and so on.
• Backoff limit (ms): The maximum backoff interval Cribl Stream/Edge should apply for its final retry, in milliseconds. Default (and minimum) is 10,000 (10 seconds); maximum is 180,000 (180 seconds, or 3 minutes).

Retry timed-out HTTP requests: When you want to automatically retry requests that have timed out, toggle this control on to display the following settings for configuring retry behavior:

• Pre-backoff interval (ms): The amount of time to wait before beginning retries, in milliseconds. Defaults to 1000 (one second).
• Backoff multiplier: The base for the exponential backoff algorithm. A value of 2 (the default) means that Cribl Stream/Edge will retry after 2 seconds, then 4 seconds, then 8 seconds, and so on.
• Backoff limit (ms): The maximum backoff interval Cribl Stream/Edge should apply for its final retry, in milliseconds. Default (and minimum) is 10,000 (10 seconds); maximum is 180,000 (180 seconds, or 3 minutes).

Advanced Settings

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Validate server certs: Reject certificates that are not authorized by a CA in the CA certificate path, or by another trusted CA (e.g., the system’s CA). Defaults to Yes. This setting is also configurable in TLS Settings (Client Side). If you enable Client-Side TLS, the validation rules defined there will override this setting.

Round-robin DNS: Toggle to Yes to use round-robin DNS lookup across multiple IP addresses, IPv4 and IPv6. When a DNS server returns multiple addresses, this will cause Cribl Stream to cycle through them in the order returned. Only displayed when the General Settings tab’s Load balancing option is disabled.

Request timeout: Amount of time (in seconds) to wait for a request to complete before aborting it. Defaults to 30.

Request concurrency: Maximum number of concurrent requests before blocking. This is set per Worker Process. Defaults to 5.

Max body size (KB): Maximum size of the request body before compression. Defaults to 4096 KB. The actual request body size might exceed the specified value because the Destination adds bytes when it writes to the downstream receiver. Cribl recommends that you experiment with the Max body size value until downstream receivers reliably accept all events.

Max events per request: Maximum number of events to include in the request body. The 0 default allows unlimited events.

Flush period (sec): Maximum time between requests. Low values could cause the payload size to be smaller than its configured maximum. Defaults to 1.

Extra HTTP headers: Name-value pairs to pass as additional HTTP headers.

Failed request logging mode: Use this drop-down to determine which data should be logged when a request fails. Select among None (the default), Payload, or Payload + Headers. With this last option, Cribl Stream will redact all headers, except non-sensitive headers that you declare below in Safe headers.

Safe headers: Add headers to declare them as safe to log in plaintext. (Sensitive headers such as authorization will always be redacted, even if listed here.) Use a tab or hard return to separate header names.

Exclude fields: Fields to exclude from the event. By default, __kube_* and __metadata are excluded. This Destination forwards all other Internal Fields.

If you are running Cribl Edge 4.0.x (or earlier) and are using the Kubernetes Metrics Source with this Destination, consider excluding the following fields to reduce event size:

!__inputId,!__outputId,!__criblMetrics,__* .

The contents of __raw are often redundant with the _raw field’s contents. Where they are identical, consider excluding one of the two.

Auth Token TTL minutes: The number of minutes before the internally generated authentication token expires, valid values between 1 and 60.

Environment: If you’re using GitOps, optionally use this field to specify a single Git branch on which to enable this configuration. If empty, the config will be enabled everywhere.

The following options are added if you enable the General Settings tab’s Load balancing option:

DNS resolution period (seconds): Re-resolve any hostnames after each interval of this many seconds, and pick up destinations from A records. Defaults to 600 seconds.

Load balance stats period (seconds): Lookback traffic history period. Defaults to 300 seconds. (Note that If multiple receivers are behind a hostname – i.e., multiple A records – all resolved IPs will inherit the weight of the host, unless each IP is specified separately. In Cribl Stream load balancing, IP settings take priority over those from hostnames.)

Internal Fields Loopback to Sources

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The Cribl HTTP and Cribl TCP Destinations differ from all other Destinations in the way they handle internal fields: They normally send data back to their respective Cribl Sources – where Cribl internal fields, metrics, and sender-generated fields can all be useful.

These Destinations forward all internal fields by default, except for any that you exclude in Advanced Settings > Exclude fields.

As examples, if the following fields are present on an event forwarded by a Cribl HTTP or Cribl TCP Destination, they’ll be accessible in the ingesting Cribl HTTP/TCP Source:__criblMetrics, __srcIpPort, __inputId, and __outputId.

Proxying Requests

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If you need to proxy HTTP/S requests, see System Proxy Configuration.