Splunk HTTP Event Collector (HEC)

Receive logs from Splunk

status: stable role: aggregator delivery: at-least-once acknowledgements: yes egress: batch state: stateless
output: logs
This source exposes three HTTP endpoints at a configurable address that jointly implement the Splunk HEC API: /services/collector/event, /services/collector/raw, and /services/collector/health.

Configuration

Example configurations

{
  "sources": {
    "my_source_id": {
      "type": "splunk_hec"
    }
  }
}
[sources.my_source_id]
type = "splunk_hec"

sources:
  my_source_id:
    type: splunk_hec

{
  "sources": {
    "my_source_id": {
      "type": "splunk_hec",
      "address": "0.0.0.0:8088",
      "valid_tokens": [
        "A94A8FE5CCB19BA61C4C08"
      ]
    }
  }
}
[sources.my_source_id]
type = "splunk_hec"
address = "0.0.0.0:8088"
valid_tokens = [ "A94A8FE5CCB19BA61C4C08" ]

sources:
  my_source_id:
    type: splunk_hec
    address: 0.0.0.0:8088
    valid_tokens:
      - A94A8FE5CCB19BA61C4C08

acknowledgements

optional object
Acknowledgement configuration for the splunk_hec source.

acknowledgements.ack_idle_cleanup

optional bool

Whether or not to remove channels after idling for max_idle_time seconds.

A channel is idling if it is not used for sending data or querying acknowledgement statuses.

default: false

acknowledgements.enabled

optional bool
Enables end-to-end acknowledgements.

acknowledgements.max_idle_time

optional uint

The amount of time, in seconds, a channel is allowed to idle before removal.

Channels can potentially idle for longer than this setting but clients should not rely on such behavior.

Minimum of 1.

default: 300

acknowledgements.max_number_of_ack_channels

optional uint

The maximum number of Splunk HEC channels clients can use with this source.

Minimum of 1.

default: 1e+06

acknowledgements.max_pending_acks

optional uint

The maximum number of acknowledgement statuses pending query across all channels.

Equivalent to the max_number_of_acked_requests_pending_query Splunk HEC setting.

Minimum of 1.

default: 1e+07

acknowledgements.max_pending_acks_per_channel

optional uint

The maximum number of acknowledgement statuses pending query for a single channel.

Equivalent to the max_number_of_acked_requests_pending_query_per_ack_channel Splunk HEC setting.

Minimum of 1.

default: 1e+06

address

optional string literal

The socket address to listen for connections on.

The address must include a port.

default: 0.0.0.0:8088

keepalive

optional object
Configuration of HTTP server keepalive parameters.

keepalive.max_connection_age_jitter_factor

optional float

The factor by which to jitter the max_connection_age_secs value.

A value of 0.1 means that the actual duration will be between 90% and 110% of the specified maximum duration.

default: 0.1

keepalive.max_connection_age_secs

optional uint

The maximum amount of time a connection may exist before it is closed by sending a Connection: close header on the HTTP response. Set this to a large value like 100000000 to “disable” this feature

Only applies to HTTP/0.9, HTTP/1.0, and HTTP/1.1 requests.

A random jitter configured by max_connection_age_jitter_factor is added to the specified duration to spread out connection storms.

Examples 
600
default: 300(seconds)

store_hec_token

optional bool

Whether or not to forward the Splunk HEC authentication token with events.

If set to true, when incoming requests contain a Splunk HEC token, the token used is kept in the event metadata and preferentially used if the event is sent to a Splunk HEC sink.

default: false

tls

optional object
Configures the TLS options for incoming/outgoing connections.

tls.alpn_protocols

optional [string]

Sets the list of supported ALPN protocols.

Declare the supported ALPN protocols, which are used during negotiation with a peer. They are prioritized in the order that they are defined.

tls.ca_file

optional string literal

Absolute path to an additional CA certificate file.

The certificate must be in the DER or PEM (X.509) format. Additionally, the certificate can be provided as an inline string in PEM format.

Examples 
"/path/to/certificate_authority.crt"

tls.crt_file

optional string literal

Absolute path to a certificate file used to identify this server.

The certificate must be in DER, PEM (X.509), or PKCS#12 format. Additionally, the certificate can be provided as an inline string in PEM format.

If this is set and is not a PKCS#12 archive, key_file must also be set.

Examples 
"/path/to/host_certificate.crt"

tls.enabled

optional bool

Whether or not to require TLS for incoming or outgoing connections.

When enabled and used for incoming connections, an identity certificate is also required. See tls.crt_file for more information.

tls.key_file

optional string literal

Absolute path to a private key file used to identify this server.

The key must be in DER or PEM (PKCS#8) format. Additionally, the key can be provided as an inline string in PEM format.

Examples 
"/path/to/host_certificate.key"

tls.key_pass

optional string literal

Passphrase used to unlock the encrypted key file.

This has no effect unless key_file is set.

Examples 
"${KEY_PASS_ENV_VAR}"
"PassWord1"

tls.server_name

optional string literal

Server name to use when using Server Name Indication (SNI).

Only relevant for outgoing connections.

Examples 
"www.example.com"

tls.verify_certificate

optional bool

Enables certificate verification. For components that create a server, this requires that the client connections have a valid client certificate. For components that initiate requests, this validates that the upstream has a valid certificate.

If enabled, certificates must not be expired and must be issued by a trusted issuer. This verification operates in a hierarchical manner, checking that the leaf certificate (the certificate presented by the client/server) is not only valid, but that the issuer of that certificate is also valid, and so on, until the verification process reaches a root certificate.

Do NOT set this to false unless you understand the risks of not verifying the validity of certificates.

tls.verify_hostname

optional bool

Enables hostname verification.

If enabled, the hostname used to connect to the remote host must be present in the TLS certificate presented by the remote host, either as the Common Name or as an entry in the Subject Alternative Name extension.

Only relevant for outgoing connections.

Do NOT set this to false unless you understand the risks of not verifying the remote hostname.

token

optional string literal

Deprecated

This option has been deprecated, use valid_tokens instead.

Optional authorization token.

If supplied, incoming requests must supply this token in the Authorization header, just as a client would if it was communicating with the Splunk HEC endpoint directly.

If not supplied, the Authorization header is ignored and requests are not authenticated.

valid_tokens

optional [string]

A list of valid authorization tokens.

If supplied, incoming requests must supply one of these tokens in the Authorization header, just as a client would if it was communicating with the Splunk HEC endpoint directly.

If not supplied, the Authorization header is ignored and requests are not authenticated.

Array string literal
Examples 
[
  "A94A8FE5CCB19BA61C4C08"
]

Outputs

<component_id>

Default output stream of the component. Use this component’s ID as an input to downstream transforms and sinks.

Output Types

Logs

Warning

The fields shown below will be different if log namespacing is enabled. See Log Namespacing for more details

Event

A single event
Fields
message required string literal
The raw line, unparsed.
Examples
2019-02-13T19:48:34+00:00 [info] Started GET "/" for 127.0.0.1
source_type required string literal
The name of the source type.
Examples
splunk_hec
splunk_channel required timestamp
The Splunk channel, value of the X-Splunk-Request-Channel header or channel query parameter, in that order of precedence.
Examples
2020-10-10T17:07:36.452332Z
timestamp required timestamp
The exact time the event was ingested into Vector.
Examples
2020-10-10T17:07:36.452332Z

Telemetry

Metrics

link

component_discarded_events_total

counter
The number of events dropped by this component.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
host optional
The hostname of the system Vector is running on.
intentional
True if the events were discarded intentionally, like a filter transform, or false if due to an error.
pid optional
The process ID of the Vector instance.

component_errors_total

counter
The total number of errors encountered by this component.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
error_type
The type of the error
host optional
The hostname of the system Vector is running on.
pid optional
The process ID of the Vector instance.
stage
The stage within the component at which the error occurred.

component_received_bytes_total

counter
The number of raw bytes accepted by this component from source origins.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
container_name optional
The name of the container from which the data originated.
file optional
The file from which the data originated.
host optional
The hostname of the system Vector is running on.
mode optional
The connection mode used by the component.
peer_addr optional
The IP from which the data originated.
peer_path optional
The pathname from which the data originated.
pid optional
The process ID of the Vector instance.
pod_name optional
The name of the pod from which the data originated.
uri optional
The sanitized URI from which the data originated.

component_received_event_bytes_total

counter
The number of event bytes accepted by this component either from tagged origins like file and uri, or cumulatively from other origins.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
container_name optional
The name of the container from which the data originated.
file optional
The file from which the data originated.
host optional
The hostname of the system Vector is running on.
mode optional
The connection mode used by the component.
peer_addr optional
The IP from which the data originated.
peer_path optional
The pathname from which the data originated.
pid optional
The process ID of the Vector instance.
pod_name optional
The name of the pod from which the data originated.
uri optional
The sanitized URI from which the data originated.

component_received_events_count

histogram

A histogram of the number of events passed in each internal batch in Vector’s internal topology.

Note that this is separate than sink-level batching. It is mostly useful for low level debugging performance issues in Vector due to small internal batches.

component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
container_name optional
The name of the container from which the data originated.
file optional
The file from which the data originated.
host optional
The hostname of the system Vector is running on.
mode optional
The connection mode used by the component.
peer_addr optional
The IP from which the data originated.
peer_path optional
The pathname from which the data originated.
pid optional
The process ID of the Vector instance.
pod_name optional
The name of the pod from which the data originated.
uri optional
The sanitized URI from which the data originated.

component_received_events_total

counter
The number of events accepted by this component either from tagged origins like file and uri, or cumulatively from other origins.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
container_name optional
The name of the container from which the data originated.
file optional
The file from which the data originated.
host optional
The hostname of the system Vector is running on.
mode optional
The connection mode used by the component.
peer_addr optional
The IP from which the data originated.
peer_path optional
The pathname from which the data originated.
pid optional
The process ID of the Vector instance.
pod_name optional
The name of the pod from which the data originated.
uri optional
The sanitized URI from which the data originated.

component_sent_event_bytes_total

counter
The total number of event bytes emitted by this component.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
host optional
The hostname of the system Vector is running on.
output optional
The specific output of the component.
pid optional
The process ID of the Vector instance.

component_sent_events_total

counter
The total number of events emitted by this component.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
host optional
The hostname of the system Vector is running on.
output optional
The specific output of the component.
pid optional
The process ID of the Vector instance.

http_server_handler_duration_seconds

histogram
The duration spent handling a HTTP request.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
host optional
The hostname of the system Vector is running on.
method optional
The HTTP method of the request.
path
The path that produced the error.
pid optional
The process ID of the Vector instance.
status optional
The HTTP status code of the request.

http_server_requests_received_total

counter
The total number of HTTP requests received.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
host optional
The hostname of the system Vector is running on.
method optional
The HTTP method of the request.
path
The path that produced the error.
pid optional
The process ID of the Vector instance.

http_server_responses_sent_total

counter
The total number of HTTP responses sent.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
host optional
The hostname of the system Vector is running on.
method optional
The HTTP method of the request.
path
The path that produced the error.
pid optional
The process ID of the Vector instance.
status optional
The HTTP status code of the request.

source_lag_time_seconds

histogram
The difference between the timestamp recorded in each event and the time when it was ingested, expressed as fractional seconds.
component_id
The Vector component ID.
component_kind
The Vector component kind.
component_type
The Vector component type.
host optional
The hostname of the system Vector is running on.
pid optional
The process ID of the Vector instance.

How it works

Context

By default, the splunk_hec source augments events with helpful context keys.

Indexer Acknowledgements

With acknowledgements enabled, the source uses the Splunk HEC indexer acknowledgements protocol to allow clients to verify data has been delivered to destination sinks. To summarize the protocol, each request to the source is associated with an integer identifier (an ack id) that the client is given and can use to query for the status of the request.

State

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 via the tls.* options and/or via an OpenSSL configuration file. The file location defaults to /usr/local/ssl/openssl.cnf or can be specified with the OPENSSL_CONF environment variable.
Sidebar