metrics: pandaproxy: default aggregations

Aggregate over shard, method by default

This accounts for pandaproxy and schema registry, so an addional
service label will be added (later).

Signed-off-by: Ben Pope <ben@redpanda.com>

src/v/pandaproxy/probe.cc

@@ -23,15 +23,26 @@ probe::probe(ss::httpd::path_description& path_desc)
         return;
     }
     namespace sm = ss::metrics;
+
+    auto operation_label = sm::label("operation");
     std::vector<sm::label_instance> labels{
-      sm::label("operation")(path_desc.operations.nickname)};
+      operation_label(path_desc.operations.nickname)};
+
+    auto aggregate_labels = std::vector<sm::label>{
+      sm::shard_label, operation_label};
+    auto internal_aggregate_labels
+      = config::shard_local_cfg().aggregate_metrics()
+          ? aggregate_labels
+          : std::vector<sm::label>{};
+
     _metrics.add_group(
       "pandaproxy",
       {sm::make_histogram(
         "request_latency",
         sm::description("Request latency"),
-        std::move(labels),
-        [this] { return _request_hist.seastar_histogram_logform(); })});
+        labels,
+        [this] { return _request_hist.seastar_histogram_logform(); },
+        internal_aggregate_labels)});
 }
 
-} // namespace pandaproxy
+} // namespace pandaproxy