Azure Blob Storage

Cribl Stream supports sending data to (and replaying specific events from) both Azure Blob Storage, and Azure Data Lake Storage Gen2, which implements a hierarchical namespace over blob data. This Destination can deliver data to Azure whether Cribl Stream is running on Azure, another cloud platform, or on-prem.

Type: Non-Streaming | TLS Support: Yes | PQ Support: No

Configuring Cribl Stream to Output to Azure Blob Storage​

From the top nav, click Manage, then select a Worker Group 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 Azure > Blob Storage. 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 Azure > Blob Storage. Next, click Add Destination to open a New Destination modal that provides the options below.

General Settings​

Output ID: Enter a unique name to identify this Destination definition.

Container name: Enter the container name. (A container organizes a set of blobs, similar to a directory in a file system.)

Container names can include only lowercase letters, numbers, and/or hyphens (-). This restriction is imposed by Azure.

Blob prefix: Root directory to prepend to path before uploading.

Staging location: Local filesystem location in which to buffer files before compressing and moving them to the final destination. Cribl recommends that this location be stable and high-performance.

The Staging location field is not displayed or available on Cribl.Cloud-managed Worker Nodes.

Data format: The output data format defaults to JSON. Raw and Parquet are also available. Selecting Parquet (supported only on Linux, not Windows) exposes a Parquet Settings left tab, where you must configure certain options in order to export data in Parquet format.

Authentication Settings ​

Use the Authentication method drop-down to select one of these options:

  • Manual: Use this default option to enter your Azure Storage connection string directly. Exposes a Connection string field for this purpose. (If left blank, Cribl Stream will fall back to env.AZURE_STORAGE_CONNECTION_STRING.)

  • Secret: This option exposes a Connection string (text secret) drop-down, in which you can select a stored secret that references an Azure Storage connection string. A Create link is available to store a new, reusable secret.

Connection String Format​

Either authentication method uses an Azure Storage connection string in this format:

DefaultEndpointsProtocol=[http|https];AccountName=<your‑account‑name>;AccountKey=<your‑account‑key>;EndpointSuffix=<your-endpoint-suffix>

A fictitious example, using Microsoft’s recommended HTTPS option, is:

DefaultEndpointsProtocol=https;AccountName=storagesample;AccountKey=12345678...32;EndpointSuffix=core.windows.net

Optional Settings​

Create container: Toggle to Yes to create the configured container in Azure Blob Storage if one does not already exist.

Partitioning expression: JavaScript expression that defines how files are partitioned and organized. Default is date-based. If blank, Cribl Stream will fall back to the event’s __partition field value (if present); or otherwise to the root directory of the Output Location and Staging Location.

Compress: Data compression format used before moving to final destination. Defaults to gzip (recommended). This setting is not available when Data format is set to Parquet.

File name prefix expression: The output filename prefix. Must be a JavaScript expression (which can evaluate to a constant), enclosed in quotes or backticks. Defaults to CriblOut.

File name suffix expression: The output filename suffix. Must be a JavaScript expression (which can evaluate to a constant), enclosed in quotes or backticks. Defaults to `.${C.env["CRIBL_WORKER_ID"]}.${__format}${__compression === "gzip" ? ".gz" : ""}`, where __format can be json or raw, and __compression can be none or gzip.

To prevent files from being overwritten, Cribl appends a random sequence of 6 characters to the end of their names. File name prefix and suffix expressions do not bypass this behavior.

For example, if you set the File name prefix expression to CriblExec and set the File name suffix expression to .csv, the file name might display as CriblExec-adPRWM.csv with adPRWM appended.

Backpressure behavior: Whether to block or drop events when all receivers are exerting backpressure. (Causes might include an accumulation of too many files needing to be closed.) Defaults to Block.

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

Processing Settings​

Post‑Processing​

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

Parquet Settings​

To write out Parquet files, note that:

  • On Linux, you can use the Cribl Stream CLI’s parquet command to view a Parquet file, its metadata, or its schema.
  • Cribl Edge Workers support Parquet only when running on Linux, not on Windows.
  • See Working with Parquet for pointers on how to avoid problems such as data mismatches.

Automatic schema: Toggle on to automatically generate a Parquet schema based on the events of each Parquet file that Cribl Stream writes. When toggled off (the default), exposes the following additional field:

  • Parquet schema: Select a schema from the drop-down.

If you need to modify a schema or add a new one, follow the instructions in our Parquet Schemas topic. These steps will propagate the freshest schema back to this drop-down.

Parquet version: Determines which data types are supported, and how they are represented. Defaults to 2.6; 2.4 and 1.0 are also available.

Data page version: Serialization format for data pages. Defaults to V2. If your toolchain includes a Parquet reader that does not support V2, use V1.

Group row limit: The number of rows that every group will contain. The final group can contain a smaller number of rows. Defaults to 10000.

Page size: Set the target memory size for page segments. Generally, set lower values to improve reading speed, or set higher values to improve compression. Value must be a positive integer smaller than the Row group size value, with appropriate units. Defaults to 1 MB.

Log invalid rows: Toggle to Yes to output up to 20 unique rows that were skipped due to data format mismatch. Log level must be set to debug for output to be visible.

Write statistics: Leave toggled on (the default) if you have Parquet tools configured to view statistics – these profile an entire file in terms of minimum/maximum values within data, numbers of nulls, etc.

Write page indexes: Leave toggled on (the default) if your Parquet reader uses statistics from Page Indexes to enable page skipping. One Page Index contains statistics for one data page.

Write page checksum: Toggle on if you have configured Parquet tools to verify data integrity using the checksums of Parquet pages.

Metadata (optional): The metadata of files the Destination writes will include the properties you add here as key-value pairs. For example, one way to tag events as belonging to the OCSF category for security findings would be to set Key to OCSF Event Class and Value to 2001.

Advanced Settings​

Max file size (MB): Maximum uncompressed output file size. Files reaching this size will be closed and moved to the final output location. Defaults to 32.

Max file open time (sec): Maximum amount of time to write to a file. Files open for longer than this limit will be closed and moved to final output location. Defaults to 300.

Max file idle time (sec): Maximum amount of time to keep inactive files open. Files open for longer than this limit will be closed and moved to final output location. Default: 30.

Max open files: Maximum number of files to keep open concurrently. When exceeded, the oldest open files will be closed and moved to final output location. Default: 100.

Cribl Stream will close files when either of the Max file size (MB) or the Max file open time (sec) conditions are met.

Max concurrent file parts: Maximum number of parts to upload in parallel per file. A value of 1 tells the Destination to send one part at a time – that is, to upload the file’s contents sequentially. Defaults to 1; highest allowed value is 10.

Add Output ID: When set to Yes (the default), adds the Output ID field’s value to the staging location’s file path. This ensures that each Destination’s logs will write to its own bucket.

For a Destination originally configured in a Cribl Stream version below 2.4.0, the Add Output ID behavior will be switched off on the backend, regardless of this toggle’s state. This is to avoid losing any files pending in the original staging directory, upon Cribl Stream upgrade and restart. To enable this option for such Destinations, Cribl’s recommended migration path is:

  • Clone the Destination.
  • Redirect the Routes referencing the original Destination to instead reference the new, cloned Destination.

This way, the original Destination will process pending files (after an idle timeout), and the new, cloned Destination will process newly arriving events with Add output ID enabled.

Remove staging dirs: Toggle to Yes to delete empty staging directories after moving files. This prevents the proliferation of orphaned empty directories. When enabled, exposes this additional option:

  • Staging cleanup period: How often (in seconds) to delete empty directories when Remove staging dirs is enabled. Defaults to 300 seconds (every 5 minutes). Minimum configurable interval is 10 seconds; maximum is 86400 seconds (every 24 hours).

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.

Internal Fields​

Cribl Stream uses a set of internal fields to assist in forwarding data to a Destination.

Field for this Destination:

  • __partition

Proxying Requests​

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