= Infinispan marshalling changes to Infinispan Protostream
Marshalling is the process of converting Java objects into bytes to send them across the network between {project_name} servers.
With {project_name} 26, we changed the marshalling format from JBoss Marshalling to Infinispan Protostream.
WARNING: JBoss Marshalling and Infinispan Protostream are not compatible with each other and incorrect usage may lead to data loss.
Consequently, all caches are cleared when upgrading to this version.
Infinispan Protostream is based on https://protobuf.dev/programming-guides/proto3/[Protocol Buffers] (proto 3), which has the advantage of backwards/forwards compatibility.