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:
| Hierarchy | Block | Description | Required |
|---|---|---|---|
| http | http | Configures the http server to serve Jaeger remote sampling. | no |
| http > tls | tls | Configures TLS for the HTTP server. | no |
| http > cors | cors | Configures CORS for the HTTP server. | no |
| grpc | grpc | Configures the grpc server to serve Jaeger remote sampling. | no |
| grpc > tls | tls | Configures TLS for the gRPC server. | no |
| grpc > keepalive | keepalive | Configures keepalive settings for the configured server. | no |
| grpc > keepalive > server_parameters | server_parameters | Server parameters used to configure keepalive settings. | no |
| grpc > keepalive > enforcement_policy | enforcement_policy | Enforcement policy for keepalive settings. | no |
| source | source | Configures the Jaeger remote sampling document. | yes |
| source > remote | remote | Configures the gRPC client used to retrieve the Jaeger remote sampling document. | no |
| source > remote > tls | tls_client | Configures TLS for the gRPC client. | no |
| source > remote > keepalive | keepalive | Configures keepalive settings for the gRPC client. | no |
| debug_metrics | debug_metrics | Configures the metrics that this component generates to monitor its state. | no |
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:
| Name | Type | Description | Default | Required |
|---|---|---|---|---|
endpoint | string | host:port to listen for traffic on. | "0.0.0.0:5778" | no |
max_request_body_size | string | Maximum request body size the server will allow. | 20MiB | no |
include_metadata | boolean | Propagate incoming connection metadata to downstream consumers. | no | |
compression_algorithms | list(string) | A list of compression algorithms the server can accept. | ["", "gzip", "zstd", "zlib", "snappy", "deflate"] | 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:
| Name | Type | Description | Default | Required |
|---|---|---|---|---|
ca_file | string | Path to the CA file. | no | |
ca_pem | string | CA PEM-encoded text to validate the server with. | no | |
cert_file | string | Path to the TLS certificate. | no | |
cert_pem | string | Certificate PEM-encoded text for client authentication. | no | |
include_system_ca_certs_pool | boolean | Whether to load the system certificate authorities pool alongside the certificate authority. | false | no |
key_file | string | Path to the TLS certificate key. | no | |
key_pem | secret | Key PEM-encoded text for client authentication. | no | |
max_version | string | Maximum acceptable TLS version for connections. | "TLS 1.3" | no |
min_version | string | Minimum acceptable TLS version for connections. | "TLS 1.2" | no |
cipher_suites | list(string) | A list of TLS cipher suites that the TLS transport can use. | [] | no |
reload_interval | duration | The duration after which the certificate is reloaded. | "0s" | no |
client_ca_file | string | Path 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_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.
cors block
The cors block configures CORS settings for an HTTP server.
The following arguments are supported:
| Name | Type | Description | Default | Required |
|---|---|---|---|---|
allowed_origins | list(string) | Allowed values for the Origin header. | no | |
allowed_headers | list(string) | Accepted headers from CORS requests. | ["X-Requested-With"] | no |
max_age | number | Configures the Access-Control-Max-Age response header. | no |
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:
| Name | Type | Description | Default | Required |
|---|---|---|---|---|
endpoint | string | host:port to listen for traffic on. | "0.0.0.0:14250" | no |
transport | string | Transport to use for the gRPC server. | "tcp" | no |
max_recv_msg_size | string | Maximum size of messages the server will accept. | "4MiB" | no |
max_concurrent_streams | number | Limit the number of concurrent streaming RPC calls. | no | |
read_buffer_size | string | Size of the read buffer the gRPC server will use for reading from clients. | "512KiB" | no |
write_buffer_size | string | Size of the write buffer the gRPC server will use for writing to clients. | no | |
include_metadata | boolean | Propagate incoming connection metadata to downstream consumers. | no |
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:
| Name | Type | Description | Default | Required |
|---|---|---|---|---|
max_connection_idle | duration | Maximum age for idle connections. | "infinity" | no |
max_connection_age | duration | Maximum age for non-idle connections. | "infinity" | no |
max_connection_age_grace | duration | Time to wait before forcibly closing connections. | "infinity" | no |
time | duration | How often to ping inactive clients to check for liveness. | "2h" | no |
timeout | duration | Time 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:
| Name | Type | Description | Default | Required |
|---|---|---|---|---|
min_time | duration | Minimum time clients should wait before sending a keepalive ping. | "5m" | no |
permit_without_stream | boolean | Allow clients to send keepalive pings when there are no active streams. | false | no |
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:
| Name | Type | Description | Default | Required |
|---|---|---|---|---|
file | string | A local file containing a Jaeger remote sampling document. | "" | no |
reload_interval | duration | The interval at which to reload the specified file. Leave at 0 to never reload. | 0 | no |
content | string | A string containing the Jaeger remote sampling contents directly. | "" | no |
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:
| Name | Type | Description | Default | Required |
|---|---|---|---|---|
endpoint | string | host:port to send telemetry data to. | yes | |
compression | string | Compression mechanism to use for requests. | "gzip" | no |
read_buffer_size | string | Size of the read buffer the gRPC client to use for reading server responses. | no | |
write_buffer_size | string | Size of the write buffer the gRPC client to use for writing requests. | "512KiB" | no |
wait_for_ready | boolean | Waits for gRPC connection to be in the READY state before sending data. | false | no |
headers | map(string) | Additional headers to send with the request. | {} | no |
authority | string | Overrides the default :authority header in gRPC requests from the gRPC client. | no | |
auth | capsule(otelcol.Handler) | Handler from an otelcol.auth component to use for authenticating requests. | no |
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, uses it for all RPCs if it connects, or tries the next address if it fails (and keeps doing that until one connection is successful). Because of this, all the RPCs will be 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:
| Name | Type | Description | Default | Required |
|---|---|---|---|---|
ca_file | string | Path to the CA file. | no | |
ca_pem | string | CA PEM-encoded text to validate the server with. | no | |
cert_file | string | Path to the TLS certificate. | no | |
cert_pem | string | Certificate PEM-encoded text for client authentication. | no | |
insecure_skip_verify | boolean | Ignores insecure server TLS certificates. | no | |
include_system_ca_certs_pool | boolean | Whether to load the system certificate authorities pool alongside the certificate authority. | false | no |
insecure | boolean | Disables TLS when connecting to the configured server. | no | |
key_file | string | Path to the TLS certificate key. | no | |
key_pem | secret | Key PEM-encoded text for client authentication. | no | |
max_version | string | Maximum acceptable TLS version for connections. | "TLS 1.3" | no |
min_version | string | Minimum acceptable TLS version for connections. | "TLS 1.2" | no |
cipher_suites | list(string) | A list of TLS cipher suites that the TLS transport can use. | [] | no |
reload_interval | duration | The duration after which the certificate is reloaded. | "0s" | no |
server_name | string | Verifies the hostname of server certificates when set. | no |
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 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.
See the Go TLS documentation for a list of supported cipher suites.
keepalive client block
The keepalive block configures keepalive settings for gRPC client
connections.
The following arguments are supported:
| Name | Type | Description | Default | Required |
|---|---|---|---|---|
ping_wait | duration | How often to ping the server after no activity. | no | |
ping_response_timeout | duration | Time to wait before closing inactive connections if the server does not respond to a ping. | no | |
ping_without_stream | boolean | Send pings even if there is no active stream request. | no |
debug_metrics block
The debug_metrics block configures the metrics that this component generates to monitor its state.
The following arguments are supported:
| Name | Type | Description | Default | Required |
|---|---|---|---|---|
disable_high_cardinality_metrics | boolean | Whether to disable certain high cardinality metrics. | true | no |
level | string | Controls 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_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
}
}


