This topic discusses PDX Serialization in Native Client for VMware GemFire.
GemFire’s Portable Data eXchange (PDX) is a cross-language data format that can reduce the cost of distributing and serializing your objects.
GemFire C++ PDX serialization:
Is interoperable with other languages by GemFire – no need to program a Java-side implementation
Reduces deserialization overhead by providing direct field access on servers of serialized data, without full deserialization. Stores data in named fields that you can access individually, to avoid the cost of deserializing the entire data object
For greater control, you can specify individual treatment for domain objects using the PdxSerializable
interface.
When you create a PdxSerializable
object, GemFire stores the object’s type information in a central registry. The information is passed between peers, between clients and servers, and between distributed systems.
When using PDX serialization, clients automatically pass registry information to servers when they store a PdxSerializable
object. Clients can run queries and functions against the data in the servers without the servers needing to know anything about the stored objects. One client can store data on the server to be retrieved by another client, with the server never needing to know the object type. This means you can code your C++ clients to manage data using Java servers without having to create Java implementations of your C++ domain objects.
The access methods for PdxSerializable
objects allow you to examine specific fields of your domain object without deserializing the entire object. This can reduce deserialization costs significantly. Client C++ apps can run queries and execute functions against the objects in the server caches without deserializing the entire object on the server side. The query engine automatically recognizes PDX objects and uses only the fields it needs.
Clients can execute Java functions on server data that only access parts of the domain objects by using PdxInstance.
Likewise, peers can access just the fields needed from the serialized object, keeping the object stored in the cache in serialized form.
You can use GemFire delta propagation with PDX serialization.
See the following sections for details on implementing PDX serialization: