The Gravwell Federator#

The Federator is an entry relay: ingesters connect to the Federator and send it entries, then the Federator passes those entries to an indexer. The Federator can act as a trust boundary, securely relaying entries across network segments without exposing ingest secrets or allowing untrusted nodes to send data for disallowed tags. The Federator upstream connections are configured like any other ingester, allowing multiplexing, local caching, encryption, etc.

IngestListener Examples#

[IngestListener "enclaveA"]
	Ingest-Secret = CustomSecrets
	TLS-Bind =
	TLS-Certfile = /opt/gravwell/etc/cert.pem
	TLS-Keyfile = /opt/gravwell/etc/key.pem

[IngestListener "enclaveB"]
	Ingest-Secret = OtherIngestSecrets
	Cleartext-Bind =

Use Cases#

  • Ingesting data across geographically diverse regions when there may not be robust connectivity

  • Providing an authentication barrier between network segments

  • Reducing the number of connections to an indexer

  • Controlling the tags a data source group can provide

  • Providing a connection buffer between a large number of ingesters and indexers


If you’re using the Gravwell Debian repository, installation is just a single apt command:

apt-get install gravwell-federator

Otherwise, download the installer from the Downloads page. Using a terminal on the Gravwell server, issue the following command as a superuser (e.g. via the sudo command) to install the Federator:

root@gravserver ~ # bash

The Federator will almost certainly require configuration for your specific setup; please refer to the following section for more information. The configuration file can be found at /opt/gravwell/etc/federator.conf. The Federator will also read configuration snippets from its configuration overlay directory (/opt/gravwell/etc/federator.conf.d).

Example Configuration#

The following example configuration connects to two upstream indexers in a protected network segment and provides ingest services on two untrusted network segments. Each untrusted ingest point has a unique Ingest-Secret, with one serving TLS with a specific certificate and key pair. The configuration file also enables a local cache, making the Federator act as a fault-tolerant buffer between the Gravwell indexers and the untrusted network segments.

	Ingest-Secret = SuperSecretUpstreamIndexerSecret
	Connection-Timeout = 0
	Insecure-Skip-TLS-Verify = false
	Max-Ingest-Cache=1024 #1GB

[IngestListener "BusinessOps"]
        Ingest-Secret = CustomBusinessSecret
        Cleartext-Bind =

[IngestListener "DMZ"]
       Ingest-Secret = OtherRandomSecret
       TLS-Bind =
       TLS-Certfile = /opt/gravwell/etc/cert.pem
       TLS-Keyfile = /opt/gravwell/etc/key.pem

Ingesters in the DMZ can connect to the Federator at using TLS encryption. These ingesters are only allowed to send entries tagged with the apache and nginx tags. Ingesters in the business network segment can connect via cleartext to and send entries tagged windows and syslog. Any mis-tagged entries will be rejected by the Federator; acceptable entries are passed to the two indexers specified in the Global section.

IngestListener Configuration#

An IngestListener can be configured to listen on any combination of cleartext connections, TLS connections, or Unix named pipe connections. Each listener must contain at least one listener and may only define a single instance of any listener type; this means a single IngestListener cannot listen on multiple cleartext connections. To enable multiple listeners of the same type, define multiple IngestListener blocks.

Each IngestListener supports the following configuration options:






Ingest authentication token


string (list)

Tags allowed to be ingested, wildcards are supported


string (list)

Name of a preprocessor to apply to ingested data, many Preprocessor parameters can be applied



Path to a Unix named pipe listener



IP:Port which defines a port and optional IP address for cleartext connections



IP:Port which defines a port and optional IP address for TLS connections



Path to an X509 public certificate file for use in TLS listeners



Path to an X509 private key file for use in TLS listeners



Optional mode to enable lower memory usage in transport buffers (default false)



Optional mode to disable downstream ingester tracking (default false)

The Low-Memory-Mode and Disable-Ingester-Tracking options are useful when supporting many transient ingesters or when you expect many hundreds or thousands of ingesters to connect. The Gravwell ingest system is designed to be low latency and high throughput, which incurs some additional memory overhead as we allocate larger read buffers. The larger read buffers may make it difficult to support many ingesters, so these options allow you to reduce ingest overhead at the expense of potentially slower ingest rates and the loss of ingester config tracking.


Common configuration errors for the Federator include:

  • Incorrect Ingest-Secret in the Global configuration

  • Incorrect Backend-Target specification(s)

  • Invalid or already-taken Bind specifications

  • Enforcing certification validation when upstream indexers or Federators do not have certificates signed by a trusted certificate authority (see the Insecure-Skip-TLS-Verify option)

  • Mismatched Ingest-Secret for downstream ingesters