Configuring Cribl Stream to Output to Amazon CloudWatch Logs

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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 Amazon > CloudWatch Logs. 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 Amazon > CloudWatch Logs. 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 CloudWatch definition.

Log group name: CloudWatch log group to associate events with.

Log stream prefix: Prefix for CloudWatch log stream name. This prefix will be used to generate a unique log stream name per Cribl Stream instance. (E.g., myStream_myHost_myOutputId.)

Region: AWS region where the CloudWatch Logs group is located.

Optional Settings

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Backpressure behavior: Select whether to block, drop, or queue events when all receivers are exerting backpressure. (Causes might include a broken or denied connection, or a rate limiter.) 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.

Persistent Queue Settings

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This tab is displayed when the Backpressure behavior is set to Persistent Queue.

On Cribl-managed Cribl.Cloud Workers (with an Enterprise plan), this tab exposes only the destructive Clear Persistent Queue button (described below in 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 will block outbound data. To configure the queue size, compression, queue-full fallback behavior, and other options below, use a hybrid Group.

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 that the queue is allowed to consume on each Worker Process. Once this limit is reached, this Destination will stop queueing data and apply the Queue‑full behavior. Required, and defaults to 5 GB. Accepts positive numbers with units of KB, MB, GB, etc. Can be set as high as 1 TB, unless you’ve configured a different Max PQ size per Worker Process in Group Settings.

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 “panic” button if you want to delete the files that are currently queued for delivery to this Destination. A confirmation modal will appear - because this will free up disk space by permanently deleting the queued data, without delivering it to downstream receivers. (Appears only after Output ID has been defined.)

Strict ordering: The default Yes position enables FIFO (first in, first out) event forwarding. When receivers recover, Cribl Stream will send earlier queued events before forwarding newly arrived events. To instead prioritize new events before draining the queue, toggle this off. Doing so will expose this additional control:

• 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’s drain rate can boost the throughput of new/active connections, by reserving more resources for them. You can further optimize Workers’ startup connections and CPU load at Group Settings > Worker Processes.

Authentication

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Use the Authentication method drop-down to select an AWS authentication method.

Auto: This default option uses the AWS instance’s metadata service to automatically obtain short-lived credentials from the IAM role attached to an EC2 instance, local credentials, sidecar, or other source. The attached IAM role grants Cribl Stream Workers access to authorized AWS resources. Can also use the environment variables AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY. Works only when running on AWS.

Manual: If not running on AWS, you can select this option to enter a static set of user-associated IAM credentials (your access key and secret key) directly or by reference. This is useful for Workers not in an AWS VPC, e.g., those running a private cloud. The Manual option exposes these corresponding additional fields:

• Access key: Enter your AWS access key. If not present, will fall back to the env.AWS_ACCESS_KEY_ID environment variable, or to the metadata endpoint for IAM role credentials.

• Secret key: Enter your AWS secret key. If not present, will fall back to the env.AWS_SECRET_ACCESS_KEY environment variable, or to the metadata endpoint for IAM credentials.

Secret: If not running on AWS, you can select this option to supply a stored secret that references an AWS access key and secret key. The Secret option exposes this additional field:

• Secret key pair: Use the drop-down to select an API key/secret key pair that you’ve configured in Cribl Stream’s secrets manager. A Create link is available to store a new, reusable secret.

Assume Role

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Enable for CloudWatch Logs: Toggle to Yes to use Assume Role credentials to access CloudWatch Logs.

AssumeRole ARN: Enter the Amazon Resource Name (ARN) of the role to assume.

External ID: Enter the External ID to use when assuming role.

Duration (seconds): Duration of the Assumed Role’s session, in seconds. Minimum is 900 (15 minutes). Maximum is 43200 (12 hours). Defaults to 3600 (1 hour).

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 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.

Advanced Settings

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Endpoint: CloudWatch Logs service endpoint. If empty, defaults to AWS’ Region-specific endpoint. Otherwise, use this field to point to a CloudWatchLogs-compatible endpoint.

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

Signature version: Signature version to use for signing CloudWatch Logs requests. Defaults to v4.

Max queue size: Maximum number of queued batches before blocking. Defaults to 5.

Max record size (KB, uncompressed): Maximum size of each individual record before compression. For non-compressible data, 1MB (the default) is the maximum recommended size.

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

Reuse connections: Whether to reuse connections between requests. The default setting (Yes) can improve performance.

Reject unauthorized certificates: Whether to accept certificates that cannot be verified against a valid Certificate Authority (e.g., self-signed certificates). Defaults to Yes.

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.

How the Amazon CloudWatch Logs Destination Batches Events

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Amazon CloudWatch Logs specifies that a batch of log events in a single request cannot span more than 24 hours.

When the Amazon CloudWatch Logs Destination transmits a batch of events, it notes the most recent event in the batch (by date-time) and drops all events in the batch that are 24 hours older (or more) than the most recent event.

To monitor dropped events, check Out of Range Dropped Event Count under Status. Alternately, you can monitor a debug log action to flag how many events are being dropped in a batch.