Change min safe polling period

CHANGELOG.md

@@ -7,6 +7,7 @@
 - [#2834](https://github.com/poanetwork/blockscout/pull/2834) - always redirect to checksummed hash
 
 ### Fixes
+- [#3028](https://github.com/poanetwork/blockscout/pull/3028) - Decrease polling period value for realtime fetcher
 - [#3027](https://github.com/poanetwork/blockscout/pull/3027) - Rescue for SUPPORTED_CHAINS env var parsing
 - [#3025](https://github.com/poanetwork/blockscout/pull/3025) - Fix splitting of indexer/web components setup
 - [#3024](https://github.com/poanetwork/blockscout/pull/3024) - Fix pool size default value in config

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

@@ -37,7 +37,7 @@ defmodule Indexer.Block.Realtime.Fetcher do
 
   @behaviour Block.Fetcher
 
-  @minimum_safe_polling_period :timer.seconds(10)
+  @minimum_safe_polling_period :timer.seconds(5)
 
   @enforce_keys ~w(block_fetcher)a
   defstruct ~w(block_fetcher subscription previous_number max_number_seen timer)a
@@ -157,7 +157,7 @@ defmodule Indexer.Block.Realtime.Fetcher do
     polling_period =
       case AverageBlockTime.average_block_time() do
         {:error, :disabled} -> 2_000
-        block_time -> round(Duration.to_milliseconds(block_time) * 2)
+        block_time -> round(Duration.to_milliseconds(block_time) / 2)
       end
 
     safe_polling_period = max(polling_period, @minimum_safe_polling_period)