From Vendor Agents

The vendor compatibility overlay adds a dedicated OpenTelemetry Collector that accepts Datadog, Jaeger, and Splunk HEC wire protocols, translates them to OTLP, and forwards to the base collector. Existing vendor agents can be reconfigured to send their telemetry to observability-stack with only an endpoint URL change — no application code changes required.

Do I need this overlay?

If your apps emit…	Need this overlay?
OpenTelemetry OTLP (gRPC or HTTP)	No. Send directly to the base collector on 4317 or 4318.
Jaeger via modern OpenTelemetry SDK + OTLP	No.
Datadog (dd-trace-* SDKs, DogStatsD)	Yes.
Jaeger native wire protocol (jaeger-client-*)	Yes.
Splunk HEC	Yes.

SignalFx is not supported. The upstream signalfxreceiver was deprecated with guidance to migrate to OTLP.

Architecture

flowchart LR
    A["Vendor agents<br/>(Datadog, Jaeger legacy, Splunk HEC)"] -->|Vendor wire protocols| B["OTel Collector<br/>(compat overlay)"]
    G["OTLP apps<br/>(incl. modern Jaeger)"] -->|OTLP| C
    B -->|OTLP| C["OTel Collector<br/>(base)"]
    C --> D["Data Prepper"]
    C --> E["Prometheus"]
    D --> F["OpenSearch"]
    E --> F

OTLP apps bypass the compat hop and send directly to the base collector. All enrichment and downstream routing happens in the base pipeline, as it does for OTLP-native traffic.

Enabling the overlay

Activation uses the standard INCLUDE_COMPOSE_* pattern used by observability-stack overlays:

echo "INCLUDE_COMPOSE_COMPAT=docker-compose.compat.yml" >> .env
docker compose up -d

This adds an otel-collector-compat service with receivers for each supported vendor, plus the bundled Jaeger hotrod demo for validation.

Verify

docker compose ps otel-collector-compat
curl -sI http://localhost:8126/info  # HTTP 200 = Datadog receiver is live

Supported vendors

Vendor	Default ports	Migration guide
Datadog	8126/tcp, 8125/udp	Datadog
Jaeger (legacy wire protocol)	14250/tcp, 14268/tcp	Jaeger
Splunk HEC	8088/tcp	Splunk HEC

Port customization

Default ports are remappable via environment variables. Useful when a real vendor agent already occupies the default port on the host.

Variable	Default	Maps to
COMPAT_DATADOG_APM_PORT	8126	Datadog trace-agent
COMPAT_DATADOG_STATSD_PORT	8125	DogStatsD
COMPAT_JAEGER_GRPC_PORT	14250	Jaeger gRPC
COMPAT_JAEGER_THRIFT_HTTP_PORT	14268	Jaeger Thrift HTTP
COMPAT_SPLUNK_HEC_PORT	8088	Splunk HEC
COMPAT_COLLECTOR_MEMORY_LIMIT	256M	Compat collector memory limit

Attribute translation

Each receiver translates vendor-specific data to the OpenTelemetry data model. Translation behavior is defined by the upstream receivers. See each per-vendor guide for canonical attribute mappings, and:

• Upstream receiver READMEs under opentelemetry-collector-contrib
• Each vendor’s own instrumentation and tagging documentation

Viewing ingested data

Once data reaches OpenSearch:

• Traces — APM for service maps and RED metrics, or Discover Traces for trace-level exploration
• Logs — Discover Logs (default index pattern: logs-otel-v1-*)
• Metrics — Discover Metrics (via Prometheus datasource)