Crate opentelemetry_etw_logs 

The ETW exporter will enable applications to use OpenTelemetry API to capture the telemetry events, and write them to the ETW subsystem.

Resource Attribute Handling

Important: By default, resource attributes are NOT exported with log records. The ETW exporter only automatically exports these specific resource attributes:

• service.name → Exported as cloud.roleName in PartA of Common Schema
• service.instance.id → Exported as cloud.roleInstance in PartA of Common Schema

All other resource attributes are ignored unless explicitly specified.

Opting in to Additional Resource Attributes

To export additional resource attributes, use the with_resource_attributes() method:

use opentelemetry_sdk::logs::SdkLoggerProvider;
use opentelemetry_sdk::Resource;
use opentelemetry_etw_logs::Processor;
use opentelemetry::KeyValue;

let etw_processor = Processor::builder("myprovider")
    // Only export specific resource attributes
    .with_resource_attributes(["custom_attribute1", "custom_attribute2"])
    .build()
    .unwrap();

let provider = SdkLoggerProvider::builder()
    .with_resource(
        Resource::builder_empty()
            .with_service_name("example")
            .with_attribute(KeyValue::new("custom_attribute1", "value1"))
            .with_attribute(KeyValue::new("custom_attribute2", "value2"))
            .with_attribute(KeyValue::new("custom_attribute3", "value3"))  // This won't be exported
            .build(),
    )
    .with_log_processor(etw_processor)
    .build();

Performance Considerations for ETW

Warning: Each specified resource attribute will be serialized and sent with EVERY log record. This is different from OTLP exporters where resource attributes are serialized once per batch. Consider the performance impact when selecting which attributes to export.

Recommendation: Be selective about which resource attributes to export. Since ETW writes to a local kernel buffer and requires a local listener/agent, the agent can often deduce many resource attributes without requiring them to be sent with each log:

• Infrastructure attributes (datacenter, region, availability zone) can be determined by the local agent.
• Host attributes (hostname, IP address, OS version) are available locally.
• Deployment attributes (environment, cluster) may be known to the agent.

Focus on attributes that are truly specific to your application instance and cannot be easily determined by the local agent.

Structs

Processor

Processes and exports logs to ETW.

ProcessorBuilder

Builder for configuring and constructing a Processor.