Add OTel data stream routing page

solutions/observability/apm/data-stream-routing.md

@@ -0,0 +1,18 @@
+---
+mapped_pages:
+applies_to:
+  stack:
+  serverless:
+---
+
+# Data stream routing [apm-open-telemetry-data-stream-routing]
+
+Elastic APM supports [routing APM data](/solutions/observability/apm/data-streams.md#apm-data-stream-rerouting) to user-defined data stream names using the [`reroute` processor](elasticsearch://reference/enrich-processor/reroute-processor.md). However, you can also ingest OTLP data without having to create new ingest pipelines.
+
+## Setting data stream attributes
+
+To automatically route OTLP data, set the `data_stream.dataset` and `data_stream.namespace` attributes. These attributes map to the respective [ECS fields](ecs://reference/ecs-data_stream.md).
+
+You can set the `data_stream` attributes in either the resource-level, scope-level, span-level or span-event-level, and they are parsed in increasing order of precedence. For example, span event `data_stream` attributes override the span `data_stream` attributes. This implies that `data_stream` attributes are inherited from previous levels. If a span doesn't specify `data_stream` attributes, it uses the scope attributes.
+
+For guidance on how to set resource attributes in OpenTelemetry, refer to [setting resource attributes](/solutions/observability/apm/attributes.md#setting-resource-attributes).

solutions/toc.yml

@@ -132,6 +132,7 @@ toc:
                       - file: observability/apm/collect-metrics.md
                       - file: observability/apm/limitations.md
                       - file: observability/apm/attributes.md
+                      - file: observability/apm/data-stream-routing.md
                   - file: observability/apm/apm-k8s-attacher.md
                   - file: observability/apm/monitor-aws-lambda-functions.md
                   - file: observability/apm/jaeger.md