These docs are for Cribl Stream 4.11 and are no longer actively maintained.

See the latest version (4.13).

Microsoft Sentinel Destination

Cribl Stream can send log and metric events to the Microsoft Sentinel SIEM. This Destination encrypts and sends events via the HTTPS protocol. The supported environments include:

• Azure Public Cloud
• Azure US Government Cloud
• Microsoft Azure operated by 21Vianet

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

For a walk-through of configuring this Destination with Microsoft Sentinel, see our Microsoft Sentinel SIEM Integration guide. Also see these Packs on the Cribl Packs Dispensary, which provide processing Pipelines that you can import and adapt to your needs:

• Microsoft Sentinel Pack.
• Microsoft Sentinel Syslog Pack.
• Microsoft Sentinel Common Security Log Pack.

Ensure that the field names in your data match the schema defined in the Data Collection Rule (DCR) for Microsoft Sentinel. The DCR specifies the expected structure, including field names and types. Mismatched field names can cause dropped events. This Destination sends out individual top-level fields, not a combined _raw (or similar) field.

Prerequisites

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Before configuring your Microsoft Sentinel Destination(s), you have to prepare the Azure workspace, create data collection rules (DCRs), and obtain the ingestion URL that will receive the data from your Destination(s).

Complete these preparatory steps, which are described in Microsoft Sentinel Integration, before configuring the Microsoft Sentinel Destination. That topic explains the overall Sentinel/Cribl workflow, provides necessary context, and shows you how to obtain the values you’ll need to configure the Destination.

If you intend to send multiple event types, or tables, to Sentinel, you’ll need a separate Destination for each event type. There are three approaches to configure this:

• Multiple Destinations: Configure separate Microsoft Sentinel Destinations, each with its own URL, and use Routes to direct data to the appropriate Destination.
• Multiple Destinations and a Output Router: Use an Output Router to split events from a single Source into multiple Destinations, each corresponding to a specific table.
• Single Destination and overwriting the URL in a Pipeline: Configure a single Microsoft Sentinel Destination and dynamically overwrite the URL within Pipelines using the __url internal field to direct events to the correct table.

Behind the scenes, this Destination uses the Azure Monitor Logs Ingestion API.

Configure Cribl Stream to Output to Microsoft Sentinel

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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 Destination and select the Destination you want from the list, choosing either Select Existing or Add New.
   • To configure via the Routes, select Data > Destinations or More > Destinations (Edge). Select the Destination you want. Next, select Add Destination.
2. In the New Destination modal, configure the following under General Settings:
   • Output ID: Enter a unique name to identify this HTTP output definition. If you clone this Destination, Cribl Stream will add -CLONE to the original Output ID.
   • Description: Optionally, enter a description.
   • Endpoint configuration: Use the buttons to select URL or ID. This specifies the method for configuring the endpoint. For details, see Endpoint Configuration Options
3. Next, you can configure the following Optional Settings:
   • Backpressure behavior: Whether to block, drop, or queue events when all receivers are exerting backpressure.
   • Tags: Optionally, add tags that you can use to filter and group Destinations on the Destinations page. These tags aren’t added to processed events. Use a tab or hard return between (arbitrary) tag names.
4. Optionally, you can adjust the Authentication Settings, Processing, Retries and Advanced settings outlined in the sections below.
5. Select Save, then Commit & Deploy.

Endpoint Configuration Options

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The Endpoint configuration setting offers the following options:

• URL – lets you directly enter the data collection endpoint. This method is the simplest way of configuring the endpoint. See Obtaining a URL for more information.

• ID – lets you enter individual IDs that Cribl Stream uses to create the URL used as the data collection endpoint.

Selecting URL exposes the following field.

URL: Endpoint URL to send events to. The internal field __url, where present in events, will override the URL and ID values. See Internal Fields below.

Selecting ID exposes the following fields.

Data collection endpoint: Data collection endpoint (DCE) in the format https://<endpoint-name>.<identifier>.<region>.ingest.monitor.azure.com.

Data collection rule ID: Immutable ID for the data collection rule (DCR).

Stream name: Name of the Sentinel table in which to store events.

Optional Settings

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Authentication Settings

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Login URL: Endpoint for the OAuth API call. This URL varies depending on your Azure environment:

• Azure Public Cloud: https://login.microsoftonline.com/<tenant-id>/oauth2/v2.0/token
• Azure US Government Cloud: https://login.microsoftonline.us/<tenant-id>/oauth2/v2.0/token
• Microsoft Azure operated by 21Vianet: https://login.chinacloudapi.cn/<tenant-id>/oauth2/v2.0/token

OAuth secret: Secret parameter value to pass in the API call’s request body.

Client ID: JavaScript expression used to compute the application (client) ID for the Azure application. Can be a constant.

Scope: The OAuth scope to the appropriate endpoint URL for your Azure environment. This ensures that your OAuth tokens are valid and that your data is correctly ingested into Microsoft Sentinel. This setting should match the specific endpoint for your Azure environment:

• Azure Public Cloud (default): https://monitor.azure.com/.default
• Azure US Government Cloud: https://monitor.azure.us/.default
• Microsoft Azure operated by 21Vianet: https://monitor.azure.cn/.default

Persistent Queue Settings

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The Persistent Queue Settings tab displays when the Backpressure behavior option in General settings is set to Persistent Queue. 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 Destination Persistent Queues (dPQ)
• Destination Backpressure Triggers

On Cribl-managed Cloud Workers (with an Enterprise plan), this tab exposes only the destructive Clear Persistent Queue button (described at the end of this section). A maximum queue size of 1 GB disk space is automatically allocated per PQ‑enabled Destination, per Worker Process. The 1 GB limit is on outbound uncompressed data, and no compression is applied to the queue.

This limit is not configurable. If the queue fills up, Cribl Stream/Edge will block outbound data. To configure the queue size, compression, queue-full fallback behavior, and other options below, use a hybrid Group.

Mode: Use this menu to select when Cribl Stream/Edge engages the persistent queue in response to backpressure events from this Destination. The options are:

If a Worker/Edge Node starts with an invalid Mode setting, it automatically switches to Error mode. This might happen if the Worker/Edge Node is running a version that does not support other modes (older than 4.9.0), or if it encounters a nonexistent value in YAML configuration files.

File size limit: 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 that the queue can consume on each Worker Process. When the queue reaches this limit, the Destination stops queueing data and applies the Queue‑full behavior. Defaults to 5 GB. This field accepts positive numbers with units of KB, MB, GB, and so on. You can set it as high as 1 TB, unless you’ve configured a different Worker Process PQ size limit on the Group Settings/Fleet Settings page.

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

Compression: Set the codec to use when compressing the persisted data after closing a file. Defaults to None. Gzip is also available.

Queue-full behavior: Whether to block or drop events when the queue begins to exert backpressure. A queue begins to exert backpressure when the disk is low or at full capacity. This setting has two options:

• Block: The output will refuse to accept new data until the receiver is ready. The system will return block signals back to the sender.
• Drop new data: Discard all new events until the backpressure event has resolved and the receiver is ready.

Backpressure duration Limit: When Mode is set to Backpressure, this setting controls how long to wait during network slowdowns before activating queues. A shorter duration enhances critical data loss prevention, while a longer duration helps avoid unnecessary queue transitions in environments with frequent, brief network fluctuations. The default value is 30 seconds.

Strict ordering: Toggle on (default) to enable FIFO (first in, first out) event forwarding, ensuring Cribl Stream/Edge sends earlier queued events first when receivers recover. The persistent queue flushes every 10 seconds in this mode. Toggle off to prioritize new events over queued events, configure a custom drain rate for the queue, and display this option:

• Drain rate limit (EPS): Optionally, set a throttling rate (in events per second) on writing from the queue to receivers. (The default 0 value disables throttling.) Throttling the queue drain rate can boost the throughput of new and active connections by reserving more resources for them. You can further optimize Worker startup connections and CPU load in the Worker Processes settings.

Clear Persistent Queue: For Cloud Enterprise only, click this button if you want to delete the files that are currently queued for delivery to this Destination. If you click this button, a confirmation modal appears. Clearing the queue frees up disk space by permanently deleting the queued data, without delivering it to downstream receivers. This button only appears after you define the Output ID.

Use the Clear Persistent Queue button with caution to avoid data loss. See Steps to Safely Disable and Clear Persistent Queues for more information.

Processing Settings

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Post‑Processing

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Pipeline: Pipeline or Pack 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.

Retries

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Honor Retry-After header: Toggle on 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. Any Retry-After header received takes precedence over all other options configured in the Retries section. Toggle off to ignore all Retry-After headers.

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: Toggle on to automatically retry requests that have timed out and 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 trusted CA (for example, the system’s CA). Toggle off if you want Cribl Stream to accept such certificates. Defaults to toggled on.

Round-robin DNS: Toggle on to enable round-robin DNS lookup across multiple IP addresses, IPv4 and IPv6. When a DNS server resolves a Fully Qualified Domain Name (FQDN) to multiple IP addresses, Cribl Stream will sequentially use each address in the order they are returned by the DNS server for subsequent connection attempts.

Compress: By default, Cribl Stream enables gzip-compress to compress the payload body before sending. Toggle this off if you want Cribl Stream not to gzip-compress the payload body.

Keep alive: By default, Cribl Stream sends Keep-Alive headers to the remote server and preserves the connection from the client side up to a maximum of 120 seconds. Toggle this off if you want Cribl Stream to close the connection immediately after sending a request.

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 per Worker Process. When Cribl Stream hits this limit, it begins throttling traffic to the downstream service. Defaults to 5. Minimum: 1. Maximum: 32.

Max body size (KB): Maximum size of the request body before compression. Defaults to 1000 KB, the maximum allowed size of API call. Be aware that high values can cause high memory usage per Worker Node, especially if a dynamically constructed URL (see Internal Fields) causes this Destination to send events to more than one URL. 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.

Buffer memory limit (KB): Total amount of memory used to buffer outgoing requests waiting to be sent. If left blank, defaults to 5 times the max body size (if set). If 0, no limit is enforced. This provides granular control over the memory allocated for buffering outgoing batched requests. Increasing the limit allows batches to grow larger before being flushed, improving efficiency for data with high cardinality (a large number of unique batches). Finding the optimal balance between efficient data transfer and memory usage involves adjusting both the Buffer memory limit and Max Body Size settings.

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 to all events as additional HTTP headers. Values will be sent encrypted. You can also add headers dynamically on a per-event basis in the __headers field. See Internal Fields below.

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.

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

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

Fields for this Destination:

• __criblMetrics
• __url
• __headers

If an event contains the internal field __criblMetrics, Cribl Stream will send it to the HTTP endpoint as a metric event. Otherwise, Cribl Stream will send it as a log event.

If an event contains the internal field __url, that field’s value will override the General Settings > URL value. This way, you can determine the endpoint URL dynamically.

For example, you could create a Pipeline containing an Eval Function that adds the __url field, and connect that Pipeline to your Microsoft Sentinel Destination. Configure the Eval Function to set __url’s value to a URL that varies depending on a global variable, or on some property of the event, or on some other dynamically-generated value that meets your needs.

If an event contains the internal field __headers, that field’s value will be a JSON object containing Name-value pairs, each of which defines a header. By creating Pipelines that set the value of __headers according to conditions that you specify, you can add headers dynamically.

For example, you could create a Pipeline containing Eval Functions that add the __headers field, and connect that Pipeline to your Microsoft Sentinel Destination. Configure the Eval Functions to set __headers values to Name-value pairs that vary depending on some properties of the event, or on dynamically-generated values that meet your needs.

Here’s an overview of how to add headers:

• To add “dynamic” (a.k.a. “custom”) headers to some events but not others, use the __headers field.
• To define headers to add to all events, use Advanced Settings > Extra HTTP Headers.
• An event can include headers added by both methods. So if you use __headers to add { "api‑key": "foo" } and Extra HTTP Headers to add { "goat": "Kid A" }, you’ll get both headers.
• Headers added via the __headers field take precedence. So if you use __headers to add { "api‑key": "foo" } and Extra HTTP Headers to add { "api‑key": "bar" }, you’ll get only one header, and that will be { "api‑key": "foo" }.

Notes on HTTP-Based Outputs

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• To proxy outbound HTTP/S requests, see System Proxy Configuration.

• Cribl Stream will attempt to use keepalives to reuse a connection for multiple requests. After two minutes of the first use, it will throw away the connection and attempt a new one. This is to prevent sticking to a particular destination when there is a constant flow of events.

• If the server does not support keepalives (or if the server closes a pooled connection while idle), Cribl Stream will establish a new connection for the next request.

• When resolving the Destination’s hostname, Cribl Stream will pick the first IP in the list for use in the next connection. Enable Round‑robin DNS to better balance distribution of events among destination cluster nodes.

Troubleshooting

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The Destination’s configuration modal has helpful tabs for troubleshooting:

Live Data: Try capturing live data to see real-time events as they flow through the Destination. On the Live Data tab, click Start Capture to begin viewing real-time data.

Logs: Review and search the logs that provide detailed information about the delivery process, including any errors or warnings that may have occurred.

Test: Ensures that the Destination is correctly set up and reachable. Verify that sample events are sent correctly by clicking Run Test.

You can also view the Monitoring page that provides a comprehensive overview of data volume and rate, helping you identify delivery issues. Analyze the graphs showing events and bytes in/out over time.