output/cloud: Raise the payload limit

output/cloud/expv2/metrics_client.go

@@ -89,17 +89,13 @@ func (mc *metricsClient) push(referenceID string, samples *pbcloud.MetricSet) er
 	return nil
 }
 
-const payloadSizeLimit = 100 * 1024 // 100 KiB
+const payloadSizeLimit = 500 * 1024 // 100 KiB
 
 func newRequestBody(data *pbcloud.MetricSet) ([]byte, error) {
 	b, err := proto.Marshal(data)
 	if err != nil {
 		return nil, fmt.Errorf("encoding metrics as Protobuf write request failed: %w", err)
 	}
-	if len(b) > payloadSizeLimit {
-		return nil, fmt.Errorf("the Protobuf message is too large to be handled from the Cloud processor; "+
-			"size: %d, limit: 100 KB", len(b))
-	}
 	// TODO: use the framing format
 	// https://github.com/google/snappy/blob/main/framing_format.txt
 	// It can be done replacing the encode with
@@ -108,5 +104,10 @@ func newRequestBody(data *pbcloud.MetricSet) ([]byte, error) {
 		return nil, fmt.Errorf("the Protobuf message is too large to be handled by Snappy encoder; "+
 			"size: %d, limit: %d", len(b), 0xffffffff)
 	}
-	return snappy.Encode(nil, b), nil
+	encoded := snappy.Encode(nil, b)
+	if len(b) > payloadSizeLimit {
+		return nil, fmt.Errorf("the compressed Protobuf message is too large to be handled from the Cloud processor; "+
+			"proto: %d B, compressed: %d B, limit: %d KiB", len(b), len(encoded), payloadSizeLimit/1024)
+	}
+	return encoded, nil
 }