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Open source

otelcol.receiver.otlp

otelcol.receiver.otlp accepts OTLP-formatted data over the network and forwards it to other otelcol.* components.

NOTE: otelcol.receiver.otlp is a wrapper over the upstream OpenTelemetry Collector otlp receiver. Bug reports or feature requests will be redirected to the upstream repository, if necessary.

Multiple otelcol.receiver.otlp components can be specified by giving them different labels.

Usage

alloy
otelcol.receiver.otlp "LABEL" {
  grpc { ... }
  http { ... }

  output {
    metrics = [...]
    logs    = [...]
    traces  = [...]
  }
}

Arguments

otelcol.receiver.otlp doesn’t support any arguments and is configured fully through inner blocks.

Blocks

The following blocks are supported inside the definition of otelcol.receiver.otlp:

HierarchyBlockDescriptionRequired
grpcgrpcConfigures the gRPC server to receive telemetry data.no
grpc > tlstlsConfigures TLS for the gRPC server.no
grpc > keepalivekeepaliveConfigures keepalive settings for the configured server.no
grpc > keepalive > server_parametersserver_parametersServer parameters used to configure keepalive settings.no
grpc > keepalive > enforcement_policyenforcement_policyEnforcement policy for keepalive settings.no
httphttpConfigures the HTTP server to receive telemetry data.no
http > tlstlsConfigures TLS for the HTTP server.no
http > corscorsConfigures CORS for the HTTP server.no
debug_metricsdebug_metricsConfigures the metrics that this component generates to monitor its state.no
outputoutputConfigures where to send received telemetry data.yes

The > symbol indicates deeper levels of nesting. For example, grpc > tls refers to a tls block defined inside a grpc block.

grpc block

The grpc block configures the gRPC server used by the component. If the grpc block isn’t provided, a gRPC server isn’t started.

The following arguments are supported:

NameTypeDescriptionDefaultRequired
endpointstringhost:port to listen for traffic on."0.0.0.0:4317"no
transportstringTransport to use for the gRPC server."tcp"no
max_recv_msg_sizestringMaximum size of messages the server will accept."4MiB"no
max_concurrent_streamsnumberLimit the number of concurrent streaming RPC calls.no
read_buffer_sizestringSize of the read buffer the gRPC server will use for reading from clients."512KiB"no
write_buffer_sizestringSize of the write buffer the gRPC server will use for writing to clients.no
include_metadatabooleanPropagate incoming connection metadata to downstream consumers.no

tls block

The tls block configures TLS settings used for a server. If the tls block isn’t provided, TLS won’t be used for connections to the server.

The following arguments are supported:

NameTypeDescriptionDefaultRequired
ca_filestringPath to the CA file.no
ca_pemstringCA PEM-encoded text to validate the server with.no
cert_filestringPath to the TLS certificate.no
cert_pemstringCertificate PEM-encoded text for client authentication.no
include_system_ca_certs_poolbooleanWhether to load the system certificate authorities pool alongside the certificate authority.falseno
key_filestringPath to the TLS certificate key.no
key_pemsecretKey PEM-encoded text for client authentication.no
max_versionstringMaximum acceptable TLS version for connections."TLS 1.3"no
min_versionstringMinimum acceptable TLS version for connections."TLS 1.2"no
cipher_suiteslist(string)A list of TLS cipher suites that the TLS transport can use.[]no
reload_intervaldurationThe duration after which the certificate is reloaded."0s"no
client_ca_filestringPath to the TLS cert to use by the server to verify a client certificate.no

If reload_interval is set to "0s", the certificate never reloaded.

The following pairs of arguments are mutually exclusive and can’t both be set simultaneously:

  • ca_pem and ca_file
  • cert_pem and cert_file
  • key_pem and key_file

If cipher_suites is left blank, a safe default list is used. Refer to the Go Cipher Suites documentation for a list of supported cipher suites.

client_ca_file sets the ClientCA and ClientAuth to RequireAndVerifyClientCert in the TLSConfig. Refer to the Go TLS documentation for more information.

keepalive block

The keepalive block configures keepalive settings for connections to a gRPC server.

keepalive doesn’t support any arguments and is configured fully through inner blocks.

server_parameters block

The server_parameters block controls keepalive and maximum age settings for gRPC servers.

The following arguments are supported:

NameTypeDescriptionDefaultRequired
max_connection_idledurationMaximum age for idle connections."infinity"no
max_connection_agedurationMaximum age for non-idle connections."infinity"no
max_connection_age_gracedurationTime to wait before forcibly closing connections."infinity"no
timedurationHow often to ping inactive clients to check for liveness."2h"no
timeoutdurationTime to wait before closing inactive clients that do not respond to liveness checks."20s"no

enforcement_policy block

The enforcement_policy block configures the keepalive enforcement policy for gRPC servers. The server will close connections from clients that violate the configured policy.

The following arguments are supported:

NameTypeDescriptionDefaultRequired
min_timedurationMinimum time clients should wait before sending a keepalive ping."5m"no
permit_without_streambooleanAllow clients to send keepalive pings when there are no active streams.falseno

http block

The http block configures the HTTP server used by the component. If the http block isn’t specified, an HTTP server isn’t started.

The following arguments are supported:

NameTypeDescriptionDefaultRequired
endpointstringhost:port to listen for traffic on."0.0.0.0:4318"no
max_request_body_sizestringMaximum request body size the server will allow.20MiBno
include_metadatabooleanPropagate incoming connection metadata to downstream consumers.no
traces_url_pathstringThe URL path to receive traces on."/v1/traces"no
metrics_url_pathstringThe URL path to receive metrics on."/v1/metrics"no
logs_url_pathstringThe URL path to receive logs on."/v1/logs"no
compression_algorithmslist(string)A list of compression algorithms the server can accept.["", "gzip", "zstd", "zlib", "snappy", "deflate"]no

To send telemetry signals to otelcol.receiver.otlp with HTTP/JSON, POST to:

  • [endpoint][traces_url_path] for traces.
  • [endpoint][metrics_url_path] for metrics.
  • [endpoint][logs_url_path] for logs.

cors block

The cors block configures CORS settings for an HTTP server.

The following arguments are supported:

NameTypeDescriptionDefaultRequired
allowed_originslist(string)Allowed values for the Origin header.no
allowed_headerslist(string)Accepted headers from CORS requests.["X-Requested-With"]no
max_agenumberConfigures the Access-Control-Max-Age response header.no

The allowed_headers argument specifies which headers are acceptable from a CORS request. The following headers are always implicitly allowed:

  • Accept
  • Accept-Language
  • Content-Type
  • Content-Language

If allowed_headers includes "*", all headers are permitted.

debug_metrics block

The debug_metrics block configures the metrics that this component generates to monitor its state.

The following arguments are supported:

NameTypeDescriptionDefaultRequired
disable_high_cardinality_metricsbooleanWhether to disable certain high cardinality metrics.trueno
levelstringControls the level of detail for metrics emitted by the wrapped collector."detailed"no

disable_high_cardinality_metrics is the Grafana Alloy equivalent to the telemetry.disableHighCardinalityMetrics feature gate in the OpenTelemetry Collector. It removes attributes that could cause high cardinality metrics. For example, attributes with IP addresses and port numbers in metrics about HTTP and gRPC connections are removed.

Note

If configured, disable_high_cardinality_metrics only applies to otelcol.exporter.* and otelcol.receiver.* components.

level is the Alloy equivalent to the telemetry.metrics.level feature gate in the OpenTelemetry Collector. Possible values are "none", "basic", "normal" and "detailed".

output block

The output block configures a set of components to forward resulting telemetry data to.

The following arguments are supported:

NameTypeDescriptionDefaultRequired
logslist(otelcol.Consumer)List of consumers to send logs to.[]no
metricslist(otelcol.Consumer)List of consumers to send metrics to.[]no
traceslist(otelcol.Consumer)List of consumers to send traces to.[]no

You must specify the output block, but all its arguments are optional. By default, telemetry data is dropped. Configure the metrics, logs, and traces arguments accordingly to send telemetry data to other components.

Exported fields

otelcol.receiver.otlp does not export any fields.

Component health

otelcol.receiver.otlp is only reported as unhealthy if given an invalid configuration.

Debug information

otelcol.receiver.otlp does not expose any component-specific debug information.

Debug metrics

  • otelcol_receiver_accepted_spans_total (counter): Number of spans successfully pushed into the pipeline.
  • otelcol_receiver_refused_spans_total (counter): Number of spans that could not be pushed into the pipeline.
  • rpc_server_duration_milliseconds (histogram): Duration of RPC requests from a gRPC server.
  • rpc_server_request_size_bytes (histogram): Measures size of RPC request messages (uncompressed).
  • rpc_server_requests_per_rpc (histogram): Measures the number of messages received per RPC. Should be 1 for all non-streaming RPCs.
  • rpc_server_response_size_bytes (histogram): Measures size of RPC response messages (uncompressed).
  • rpc_server_responses_per_rpc (histogram): Measures the number of messages received per RPC. Should be 1 for all non-streaming RPCs.

Example

This example forwards received telemetry data through a batch processor before finally sending it to an OTLP-capable endpoint:

alloy
otelcol.receiver.otlp "default" {
  http {}
  grpc {}

  output {
    metrics = [otelcol.processor.batch.default.input]
    logs    = [otelcol.processor.batch.default.input]
    traces  = [otelcol.processor.batch.default.input]
  }
}

otelcol.processor.batch "default" {
  output {
    metrics = [otelcol.exporter.otlp.default.input]
    logs    = [otelcol.exporter.otlp.default.input]
    traces  = [otelcol.exporter.otlp.default.input]
  }
}

otelcol.exporter.otlp "default" {
  client {
    endpoint = sys.env("OTLP_ENDPOINT")
  }
}

Technical details

otelcol.receiver.otlp supports gzip for compression.

Compatible components

otelcol.receiver.otlp can accept arguments from the following components:

Note

Connecting some components may not be sensible or components may require further configuration to make the connection work correctly. Refer to the linked documentation for more details.