Greetings, I am working on a project that needs to process around 100k events per second and I'm trying to improve performance.
Most of the classes being used are POJOs but have a couple of fields using a `java.util` class, either `ArrayList`, `HashSet` or `SortedSet` etc. This forces Flink to use Kyro and throw these warnings: ``` class java.util.ArrayList does not contain a setter for field size Class class java.util.ArrayList cannot be used as a POJO type because not all fields are valid POJO fields, and must be processed as GenericType. Please read the Flink documentation on "Data Types & Serialization" for details of the effect on performance and schema evolution. ``` ``` No fields were detected for class java.util.HashSet so it cannot be used as a POJO type and must be processed as GenericType. Please read the Flink documentation on "Data Types & Serialization" for details of the effect on performance and schema evolution. I read through the documentation and stackoverflow and the conclusion is that I need to make a TypeInfoFactory and use it inside a TypeInfo annotation over my POJO. ``` My question is what do I need to do to get Flink to recognize my classes as POJOs and use the POJO serializer for better performance? I read through the documentation and stackoverflow and the conclusion is that I need to make a TypeInfoFactory and use it inside a TypeInfo annotation over my POJO. While this seems incredibly tedious and I keep thinking "there must be a better way", I would be fine with this solution if I could figure out how to do this for the Set types I'm using. Any help would be appreciated.
