Log block import timings

apps/indexer/lib/indexer/block/realtime/fetcher.ex

@@ -290,8 +290,14 @@ defmodule Indexer.Block.Realtime.Fetcher do
 
   @decorate span(tracer: Tracer)
   defp do_fetch_and_import_block(block_number_to_fetch, block_fetcher, retry) do
-    case fetch_and_import_range(block_fetcher, block_number_to_fetch..block_number_to_fetch) do
-      {:ok, %{inserted: _, errors: []}} ->
+    time_before = Timex.now()
+
+    {fetch_duration, result} =
+      :timer.tc(fn -> fetch_and_import_range(block_fetcher, block_number_to_fetch..block_number_to_fetch) end)
+
+    case result do
+      {:ok, %{inserted: inserted, errors: []}} ->
+        log_import_timings(inserted, fetch_duration, time_before)
         Logger.debug("Fetched and imported.")
 
       {:ok, %{inserted: _, errors: [_ | _] = errors}} ->
@@ -355,6 +361,14 @@ defmodule Indexer.Block.Realtime.Fetcher do
     end
   end
 
+  defp log_import_timings(%{blocks: [%{number: number, timestamp: timestamp}]}, fetch_duration, time_before) do
+    node_delay = Timex.diff(time_before, timestamp, :seconds)
+
+    Logger.info("Block #{number} fetching duration: #{fetch_duration / 1_000_000}s. Node delay: #{node_delay}s.")
+  end
+
+  defp log_import_timings(_inserted, _duration, _time_before), do: nil
+
   defp retry_fetch_and_import_block(%{retry: retry}) when retry < 1, do: :ignore
 
   defp retry_fetch_and_import_block(%{changesets: changesets} = params) do