For local "heap-memory" caches, each key/value stored are being converted to a byte unnecessarily.
The reason that this conversion is taking place, is due to a combination of 1) the key/value encoding type of Wildfly's "heap-memory" caches not being explicitly configured. 2) Wildfly using Infinispan in server mode by configuring . This causes Infinispan `StorageConfigurationManager` to configure the storage media type as `application/unknown`, which results in the `application/x-java-object` key/values being converted to byte on every put operation.
The simplest solution is to update the "heap-memory" caches to explicitly configure the encoding as `application/x-java-object`. This will be mandatory in future versions anyway, as the `application/unknown` type has been deprecated.