Merge pull request #9778 from kjellwinblad/kjell/fix/kafka_atom_leak/EMQX-8739

fix: atom leak when doing Kafka bridge dry-run

lib-ee/emqx_ee_bridge/src/kafka/emqx_bridge_impl_kafka_producer.erl

@@ -75,7 +75,16 @@ on_start(InstId, Config) ->
             }),
             throw(failed_to_start_kafka_client)
     end,
-    WolffProducerConfig = producers_config(BridgeName, ClientId, ProducerConfig),
+    %% Check if this is a dry run
+    TestIdStart = string:find(InstId, ?TEST_ID_PREFIX),
+    IsDryRun =
+        case TestIdStart of
+            nomatch ->
+                false;
+            _ ->
+                string:equal(TestIdStart, InstId)
+        end,
+    WolffProducerConfig = producers_config(BridgeName, ClientId, ProducerConfig, IsDryRun),
     case wolff:ensure_supervised_producers(ClientId, KafkaTopic, WolffProducerConfig) of
         {ok, Producers} ->
             {ok, #{
@@ -241,7 +250,7 @@ ssl(#{enable := true} = SSL) ->
 ssl(_) ->
     [].
 
-producers_config(BridgeName, ClientId, Input) ->
+producers_config(BridgeName, ClientId, Input, IsDryRun) ->
     #{
         max_batch_bytes := MaxBatchBytes,
         compression := Compression,
@@ -271,7 +280,7 @@ producers_config(BridgeName, ClientId, Input) ->
     BridgeType = kafka,
     ResourceID = emqx_bridge_resource:resource_id(BridgeType, BridgeName),
     #{
-        name => make_producer_name(BridgeName),
+        name => make_producer_name(BridgeName, IsDryRun),
         partitioner => partitioner(PartitionStrategy),
         partition_count_refresh_interval_seconds => PCntRefreshInterval,
         replayq_dir => ReplayqDir,
@@ -302,12 +311,20 @@ make_client_id(BridgeName) ->
 
 %% Producer name must be an atom which will be used as a ETS table name for
 %% partition worker lookup.
-make_producer_name(BridgeName) when is_atom(BridgeName) ->
-    make_producer_name(atom_to_list(BridgeName));
-make_producer_name(BridgeName) ->
-    %% Woff needs atom for ets table name registration
-    %% The assumption here is bridge is not often re-created
-    binary_to_atom(iolist_to_binary(["kafka_producer_", BridgeName])).
+make_producer_name(BridgeName, IsDryRun) when is_atom(BridgeName) ->
+    make_producer_name(atom_to_list(BridgeName), IsDryRun);
+make_producer_name(BridgeName, IsDryRun) ->
+    %% Woff needs an atom for ets table name registration. The assumption here is
+    %% that bridges with new names are not often created.
+    case IsDryRun of
+        true ->
+            %% It is a dry run and we don't want to leak too many atoms
+            %% so we use the default producer name instead of creating
+            %% an unique name.
+            probing_wolff_producers;
+        false ->
+            binary_to_atom(iolist_to_binary(["kafka_producer_", BridgeName]))
+    end.
 
 with_log_at_error(Fun, Log) ->
     try