fix(collector): Don't split metric exports across batches

collector/config.yaml

@@ -8,11 +8,27 @@ receivers:
 
 processors:
   batch:
-    # batch metrics before sending to reduce API usage
+    # Traces pipeline: cap request size. Metrics use batch/metrics below.
     send_batch_max_size: 200
     send_batch_size: 200
     timeout: 5s
 
+  # Metrics pipeline: batch WITHOUT send_batch_max_size (0 = no upper limit).
+  #
+  # The googlemanagedprometheus exporter already chunks CreateTimeSeries into
+  # GCM's hard limit of 200 timeseries/request internally, and it emits the
+  # target_info / otel_scope_info series once per PushMetrics call. If the
+  # batch processor splits a single ~60s export into multiple batches (as
+  # send_batch_max_size: 200 does once total series > 200), the exporter runs
+  # once per batch and re-emits those info series with near-identical
+  # timestamps, which GMP rejects with "One or more points were written more
+  # frequently than the maximum sampling period configured for the metric".
+  # Leaving send_batch_max_size unset keeps each export in a single PushMetrics
+  # call, so the info series are written exactly once regardless of cardinality.
+  batch/metrics:
+    send_batch_size: 200
+    timeout: 5s
+
   memory_limiter:
     # drop metrics if memory usage gets too high
     check_interval: 1s
@@ -53,5 +69,5 @@ service:
       exporters: [googlecloud]
     metrics:
       receivers: [otlp]
-      processors: [batch, memory_limiter, resource_detection, resource]
+      processors: [batch/metrics, memory_limiter, resource_detection, resource]
       exporters: [googlemanagedprometheus]