Humio metrics

Deliver metric event data to Humio

status: beta delivery: at-least-once egress: batch state: stateless



optional object
Configures the sink batching behavior.


optional uint
The maximum size of a batch, in bytes, before it is flushed.
default: 1.049e+06 (bytes)


optional uint
The maximum age of a batch before it is flushed.
default: 1 (seconds)


optional object
Configures the sink specific buffer behavior.


optional uint
The maximum number of events allowed in the buffer.
Relevant when: type = "memory"
default: 500 (events)


required uint
The maximum size of the buffer on the disk.
Relevant when: type = "disk"


optional string enum literal
The buffer’s type and storage mechanism.
Enum options
diskStores the sink’s buffer on disk. This is less performant, but durable. Data will not be lost between restarts. Will also hold data in memory to enhance performance. WARNING: This may stall the sink if disk performance isn’t on par with the throughput. For comparison, AWS gp2 volumes are usually too slow for common cases.
memoryStores the sink’s buffer in memory. This is more performant, but less durable. Data will be lost if Vector is restarted forcefully.
default: memory


optional string enum literal
The behavior when the buffer becomes full.
Enum options
blockApplies back pressure when the buffer is full. This prevents data loss, but will cause data to pile up on the edge.
drop_newestDrops new data as it’s received. This data is lost. This should be used when performance is the highest priority.
default: block


common optional string enum

The compression strategy used to compress the encoded event data before transmission.

Some cloud storage API clients and browsers will handle decompression transparently, so files may not always appear to be compressed depending how they are accessed.

Enum options string literal
gzipGzip standard DEFLATE compression.
default: none


required object
Configures the encoding specific sink behavior.


required string literal
The encoding codec used to serialize the events before outputting.


optional array
Prevent the sink from encoding the specified fields.


optional array
Makes the sink encode only the specified fields.


optional string enum literal
How to format event timestamps.
Enum options
rfc3339Formats as a RFC3339 string
unixFormats as a unix timestamp
default: rfc3339


optional string
The base URL of the Humio instance.


optional string

The type of events sent to this sink. Humio uses this as the name of the parser to use to ingest the data.

If unset, Humio will default it to none.


common optional object
Health check options for the sink.


optional bool
Enables/disables the healthcheck upon Vector boot.
default: true


common optional string
The name of the log field to be used as the hostname sent to Humio. This overrides the global host_key option.


required [string]

A list of upstream source or transform IDs. Wildcards (*) are supported but must be the last character in the ID.

See configuration for more info.

Array string literal


optional object
Configures the sink request behavior.


optional object
Configure the adaptive concurrency algorithms. These values have been tuned by optimizing simulated results. In general you should not need to adjust these.


optional uint
The maximum number of in-flight requests allowed at any given time.
default: 10 (requests)


optional uint
The time window, in seconds, used for the rate_limit_num option.
default: 1 (seconds)


optional uint
The maximum number of requests allowed within the rate_limit_duration_secs time window.
default: 10


optional uint
The maximum number of retries to make for failed requests. The default, for all intents and purposes, represents an infinite number of retries.
default: 1.8446744073709552e+19


optional uint
The amount of time to wait before attempting the first retry for a failed request. Once, the first retry has failed the fibonacci sequence will be used to select future backoffs.
default: 1 (seconds)


optional uint
The maximum amount of time, in seconds, to wait between retries.
default: 10 (seconds)


optional uint
The maximum time a request can take before being aborted. It is highly recommended that you do not lower this value below the service’s internal timeout, as this could create orphaned requests, pile on retries, and result in duplicate data downstream.
default: 60 (seconds)


optional string
The source of events sent to this sink. Typically the filename the logs originated from. Maps to @source in Humio.


optional object
Configures the TLS options for incoming connections.


optional string literal
Absolute path to an additional CA certificate file, in DER or PEM format (X.509), or an inline CA certificate in PEM format.


optional string literal
Absolute path to a certificate file used to identify this connection, in DER or PEM format (X.509) or PKCS#12, or an inline certificate in PEM format. If this is set and is not a PKCS#12 archive, key_file must also be set.


optional string literal
Absolute path to a private key file used to identify this connection, in DER or PEM format (PKCS#8), or an inline private key in PEM format. If this is set, crt_file must also be set.


optional string literal
Pass phrase used to unlock the encrypted key file. This has no effect unless key_file is set.


optional bool
If true (the default), Vector will validate the configured remote host name against the remote host’s TLS certificate. Do NOT set this to false unless you understand the risks of not verifying the remote hostname.
default: true


required string
Your Humio ingestion token.





The number of events accepted by this component either from tagged origin like file and uri, or cumulatively from other origins.
component_kind required
The Vector component kind.
component_name required
The Vector component name.
component_type required
The Vector component type.
container_name optional
The name of the container from which the event originates.
file optional
The file from which the event originates.
mode optional
The connection mode used by the component.
peer_addr optional
The IP from which the event originates.
peer_path optional
The pathname from which the event originates.
pod_name optional
The name of the pod from which the event originates.
uri optional
The sanitized URI from which the event originates.


The total number of events emitted by this component.
component_kind required
The Vector component kind.
component_name required
The Vector component name.
component_type required
The Vector component type.

How it works

Buffers and batches

Group 2 Created with Sketch.

This component buffers & batches data as shown in the diagram above. You’ll notice that Vector treats these concepts differently, instead of treating them as global concepts, Vector treats them as sink specific concepts. This isolates sinks, ensuring services disruptions are contained and delivery guarantees are honored.

Batches are flushed when 1 of 2 conditions are met:

  1. The batch age meets or exceeds the configured timeout_secs.
  2. The batch size meets or exceeds the configured max_size or max_events.

Buffers are controlled via the buffer.* options.

Health checks

Health checks ensure that the downstream service is accessible and ready to accept data. This check is performed upon sink initialization. If the health check fails an error will be logged and Vector will proceed to start.

Require health checks

If you’d like to exit immediately upon a health check failure, you can pass the --require-healthy flag:

vector --config /etc/vector/vector.toml --require-healthy

Disable health checks

If you’d like to disable health checks for this sink you can set the healthcheck option to false.


Metrics are converted to log events via the log_to_event transform prior to sending to humio.


Vector supports dynamic configuration values through a simple template syntax. If an option supports templating, it will be noted with a badge and you can use event fields to create dynamic values. For example:

dynamic_option = "application={{ application_id }}"

In the above example, the application_id for each event will be used to partition outgoing data.

Rate limits & adapative concurrency

Adaptive Request Concurrency (ARC)

Adaptive Requst Concurrency is a feature of Vector that does away with static rate limits and automatically optimizes HTTP concurrency limits based on downstream service responses. The underlying mechanism is a feedback loop inspired by TCP congestion control algorithms. Checkout the announcement blog post,

We highly recommend enabling this feature as it improves performance and reliability of Vector and the systems it communicates with.

To enable, set the request.concurrency option to adaptive:

  request.concurrency = "adaptive"

Static rate limits

If Adaptive Request Concurrency is not for you, you can manually set static rate limits with the request.rate_limit_duration_secs, request.rate_limit_num, and request.concurrency options:

  request.rate_limit_duration_secs = 1
  request.rate_limit_num = 10
  request.concurrency = 10

Retry policy

Vector will retry failed requests (status == 429, >= 500, and != 501). Other responses will not be retried. You can control the number of retry attempts and backoff rate with the request.retry_attempts and request.retry_backoff_secs options.


This component is stateless, meaning its behavior is consistent across each input.

Transport Layer Security (TLS)

Vector uses OpenSSL for TLS protocols due to OpenSSL’s maturity. You can enable and adjust TLS behavior using the tls.* options.