Update collector config.

deploy/observability/otel-collector-config.yaml

@@ -26,7 +26,7 @@ processors:
     send_batch_size: 1024
 
 exporters:
-  # Forward everything to the OpenObserve OTLP/HTTP endpoint.
+  # Forward logs and traces to the OpenObserve OTLP/HTTP endpoint.
   otlphttp/openobserve:
     endpoint: http://openobserve:5080/api/default
     headers:
@@ -34,6 +34,14 @@ exporters:
     tls:
       insecure: true
 
+  # OpenObserve metrics are ingested via Prometheus remote-write.
+  prometheusremotewrite/openobserve:
+    endpoint: http://openobserve:5080/api/default/prometheus/api/v1/write
+    headers:
+      Authorization: Basic ${env:OPENOBSERVE_AUTH_TOKEN}
+    tls:
+      insecure: true
+
   # Echo pipeline data to the collector's own logs (useful for debugging).
   debug:
     verbosity: detailed
@@ -47,7 +55,7 @@ service:
     metrics:
       receivers: [otlp, prometheus]
       processors: [batch]
-      exporters: [otlphttp/openobserve]
+      exporters: [prometheusremotewrite/openobserve]
     logs:
       receivers: [otlp]
       processors: [batch]

docs/ARCHITECTURE.md

@@ -1395,8 +1395,11 @@ enforcing the adapter boundary even in dependency ordering.
   (`OTEL_EXPORTER_OTLP_ENDPOINT`).
 - The collector also scrapes Prometheus `/metrics` from `api:9100` and each
   worker (`:9101`/`:9102`/`:9104`/`:9105`/`:9103`).
-- A dedicated `otlphttp/openobserve` exporter forwards all signals to
+- `otlphttp/openobserve` exporter forwards logs and traces to
   `http://openobserve:5080/api/default` using `OPENOBSERVE_AUTH_TOKEN`.
+- `prometheusremotewrite/openobserve` exporter forwards metrics to
+  `http://openobserve:5080/api/default/prometheus/api/v1/write` because
+  OpenObserve ingests metrics through the Prometheus remote-write path.
 - OpenObserve UI is exposed under `/openobserve/` via nginx.
 
 ### OpenTelemetry (`core/telemetry.py`)