Important: This documentation is about an older version. It's relevant only to the release noted, many of the features and functions have been updated or replaced. Please view the current version.
otelcol.extension.jaeger_remote_sampling
otelcol.extension.jaeger_remote_sampling serves a specified Jaeger remote sampling document.
Note
otelcol.extension.jaeger_remote_samplingis a wrapper over the upstream OpenTelemetry Collectorjaegerremotesamplingextension. Bug reports or feature requests will be redirected to the upstream repository, if necessary.
Multiple otelcol.extension.jaeger_remote_sampling components can be specified by giving them different labels.
Usage
otelcol.extension.jaeger_remote_sampling "LABEL" {
source {
}
}Arguments
otelcol.extension.jaeger_remote_sampling doesn’t support any arguments and is configured fully through inner blocks.
Blocks
The following blocks are supported inside the definition of
otelcol.extension.jaeger_remote_sampling:
The > symbol indicates deeper levels of nesting. For example, grpc > tls
refers to a tls block defined inside a grpc block.
http block
The http block configures an HTTP server which serves the Jaeger remote sampling document.
The following arguments are supported:
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:
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_pemandca_filecert_pemandcert_filekey_pemandkey_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.
The curve_preferences argument determines the set of elliptic curves to prefer during a handshake in preference order.
If not provided, a default list is used.
The set of elliptic curves available are X25519, P521, P256, and P384.
cors block
The cors block configures CORS settings for an HTTP server.
The following arguments are supported:
The allowed_headers specifies which headers are acceptable from a CORS
request. The following headers are always implicitly allowed:
AcceptAccept-LanguageContent-TypeContent-Language
If allowed_headers includes "*", all headers will be permitted.
grpc block
The grpc block configures a gRPC server which serves the Jaeger remote
sampling document.
The following arguments are supported:
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:
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:
source block
The source block configures the method of retrieving the Jaeger remote sampling document
that is served by the servers specified in the grpc and http blocks.
The following arguments are supported:
Exactly one of the file argument, content argument or remote block must be specified.
remote block
The remote block configures the gRPC client used by the component.
The following arguments are supported:
By default, requests are compressed with Gzip.
The compression argument controls which compression mechanism to use. Supported strings are:
"gzip""zlib""deflate""snappy""zstd"
If you set compression to "none" or an empty string "", the requests aren’t compressed.
The supported values for balancer_name are listed in the gRPC documentation on Load balancing:
pick_first: Tries to connect to the first address. It uses the address for all RPCs if it connects, or if it fails, it tries the next address and keeps trying until one connection is successful. Because of this, all the RPCs are sent to the same backend.round_robin: Connects to all the addresses it sees and sends an RPC to each backend one at a time in order. For example, the first RPC is sent to backend-1, the second RPC is sent to backend-2, and the third RPC is sent to backend-1.
The :authority header in gRPC specifies the host to which the request is being sent.
It’s similar to the Host header in HTTP requests.
By default, the value for :authority is derived from the endpoint URL used for the gRPC call.
Overriding :authority could be useful when routing traffic using a proxy like Envoy, which makes routing decisions based on the value of the :authority header.
An HTTP proxy can be configured through the following environment variables:
HTTPS_PROXYNO_PROXY
The HTTPS_PROXY environment variable specifies a URL to use for proxying
requests. Connections to the proxy are established via the HTTP CONNECT
method.
The NO_PROXY environment variable is an optional list of comma-separated
hostnames for which the HTTPS proxy should not be used. Each hostname can be
provided as an IP address (1.2.3.4), an IP address in CIDR notation
(1.2.3.4/8), a domain name (example.com), or *. A domain name matches
that domain and all subdomains. A domain name with a leading “.”
(.example.com) matches subdomains only. NO_PROXY is only read when
HTTPS_PROXY is set.
Because otelcol.extension.jaeger_remote_sampling uses gRPC, the configured proxy server must be
able to handle and proxy HTTP/2 traffic.
tls client block
The tls block configures TLS settings used for the connection to the gRPC
server.
The following arguments are supported:
If the server doesn’t support TLS, you must set the insecure argument to true.
To disable tls for connections to the server, set the insecure argument to true.
If you set reload_interval to "0s", the certificate never reloaded.
The following pairs of arguments are mutually exclusive and can’t both be set simultaneously:
ca_pemandca_filecert_pemandcert_filekey_pemandkey_file
If cipher_suites is left blank, a safe default list is used.
Refer to the Go TLS documentation for a list of supported cipher suites.
The curve_preferences argument determines the set of elliptic curves to prefer during a handshake in preference order.
If not provided, a default list is used.
The set of elliptic curves available are X25519, P521, P256, and P384.
keepalive client block
The keepalive block configures keepalive settings for gRPC client
connections.
The following arguments are supported:
debug_metrics block
The debug_metrics block configures the metrics that this component generates to monitor its state.
The following arguments are supported:
disable_high_cardinality_metrics is the 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_metricsonly applies tootelcol.exporter.*andotelcol.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".
Component health
otelcol.extension.jaeger_remote_sampling is only reported as unhealthy if given an invalid
configuration.
Debug information
otelcol.extension.jaeger_remote_sampling does not expose any component-specific debug information.
Examples
Serving from a file
This example configures the Jaeger remote sampling extension to load a local json document and serve it over the default http port of 5778. Currently this config style exists for consistency with upstream Opentelemetry Collector components and may be removed.
otelcol.extension.jaeger_remote_sampling "example" {
http {
}
source {
file = "/path/to/jaeger-sampling.json"
reload_interval = "10s"
}
}Serving from another component
This example uses the output of a component to determine what sampling rules to serve:
local.file "sampling" {
filename = "/path/to/jaeger-sampling.json"
}
otelcol.extension.jaeger_remote_sampling "example" {
http {
}
source {
content = local.file.sampling.content
}
}Enable authentication
You can use jaeger_remote_sampling to authenticate requests.
This allows you to limit access to the sampling document.
Note
Not all OpenTelemetry Collector authentication plugins support receiver authentication. Refer to the documentation for each
otelcol.auth.*component to determine its compatibility.
otelcol.extension.jaeger_remote_sampling "default" {
http {
auth = otelcol.auth.basic.creds.handler
}
grpc {
auth = otelcol.auth.basic.creds.handler
}
}
otelcol.auth.basic "creds" {
username = sys.env("USERNAME")
password = sys.env("PASSWORD")
}


