Prometheus remote write

Collect metrics from Prometheus

status: beta role: daemon role: sidecar delivery: at-least-once acknowledgements: yes egress: batch state: stateless
output: metrics

Configuration

Example configurations

{
  "sources": {
    "my_source_id": {
      "type": "prometheus_remote_write",
      "address": "0.0.0.0:9090"
    }
  }
}
[sources.my_source_id]
type = "prometheus_remote_write"
address = "0.0.0.0:9090"

sources:
  my_source_id:
    type: prometheus_remote_write
    address: 0.0.0.0:9090

{
  "sources": {
    "my_source_id": {
      "type": "prometheus_remote_write",
      "address": "0.0.0.0:9090"
    }
  }
}
[sources.my_source_id]
type = "prometheus_remote_write"
address = "0.0.0.0:9090"

sources:
  my_source_id:
    type: prometheus_remote_write
    address: 0.0.0.0:9090

acknowledgements

optional object

Deprecated

This field is deprecated.

Controls how acknowledgements are handled by this source.

This setting is deprecated in favor of enabling acknowledgements at the global or sink level.

Enabling or disabling acknowledgements at the source level has no effect on acknowledgement behavior.

See End-to-end Acknowledgements for more information on how event acknowledgement is handled.

acknowledgements.enabled

optional bool
Whether or not end-to-end acknowledgements are enabled for this source.

address

required string literal

The socket address to accept connections on.

The address must include a port.

Examples 
"0.0.0.0:9090"

auth

optional object

Configuration of the authentication strategy for server mode sinks and sources.

Use the HTTP authentication with HTTPS only. The authentication credentials are passed as an HTTP header without any additional encryption beyond what is provided by the transport itself.

auth.password

required string literal
The basic authentication password.
Relevant when: strategy = "basic"
Examples 
"${PASSWORD}"
"password"

auth.source

required string literal
The VRL boolean expression.
Relevant when: strategy = "custom"

auth.strategy

required string literal enum
The authentication strategy to use.
Enum options
OptionDescription
basic

Basic authentication.

The username and password are concatenated and encoded using base64.

custom

Custom authentication using VRL code.

Takes in request and validates it using VRL code.

Examples 
"basic"
"custom"

auth.username

required string literal
The basic authentication username.
Relevant when: strategy = "basic"
Examples 
"${USERNAME}"
"username"

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)

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.

Outputs

<component_id>

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

Output Types

Metrics

counter

counter
A single value that can be incremented or reset to a zero value but not decremented.
* optional
Any tags present on the metric.

gauge

gauge
A gauge represents a point-in-time value that can increase and decrease. Vector’s internal gauge type represents changes to that value. Gauges should be used to track fluctuations in values, like current memory or CPU usage.
* optional
Any tags present on the metric.

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

Authorization configuration

This component has a server component that supports authorization. Authorization supports multiple strategies. Basic access authentication is the default, which supports defining a username and password to be used when connecting to the server.

Custom authorization provides a greater flexibility. It supports writing custom authorization code using VRL. Here is an example that looks up the token in an enrichment table backed by a CSV file.

Currently custom VRL auth has access to headers, path, and address (IP address of the client).

sources:
  prometheus_remote_write_source:
	type: "prometheus_remote_write"
	# ...
	auth:
	  strategy: "custom"
	  source: |-
		# We can access request headers here
		# Let's say that we expect a custom authorization header
		# In format "Vector {uuid}"
		parts = split!(.headers.authorization, " ", 2)
		# We expect Authorization header in format "Vector {uuid}"
		if parts[0] != "Vector" {
		  # The header didn't start with Vector, reject
		  # Returning false means that authentication should fail
		  false
		} else {
		  # Look for uuid in enrichment table (let's say that it has a token column)
		  # Any errors also reject requests
		  # We could then do some additional checks on the result from the table
		  result = get_enrichment_table_record!("auth_data", { "token": parts[1] })
		  # No errors, so we can return true
		  true
		}
	# ...

Context

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

Duplicate tag names

Multiple tags with the same name are invalid within Prometheus. Prometheus itself will reject a metric with duplicate tags. Vector will accept the metric, but will only take the last value for each tag name specified.

Metric type interpretation

The remote_write protocol used by this source transmits only the metric tags, timestamp, and numerical value. No explicit information about the original type of the metric (i.e. counter, histogram, etc) is included. As such, this source makes a guess as to what the original metric type was.

For metrics named with a suffix of _total, this source emits the value as a counter metric. All other metrics are emitted as gauges.

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.
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