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- Use CompatibleFieldSerializer and have everything out of the box
- Create custom serializers and deal with the versioning control on our own. This is much more work, but should provide at least 20%-30% faster solution. This is actually very close to Externalizable Interface, but in my opinion much easier because serializers for Java classes already exist in the library.
Backward/forward compatibility problems with Kyro
As already said Kyro provides the CompatibleFieldSerializer class that can provide limited backward/forward compatibility. Limited because the type of the field can not be changed. However the way the Kyro handles the compatibility is quite problematic.
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The pros and cons from these two possibilities are quite clear. First one has less data because it does not have to write also which fields are serialized, but on the other hand de-serialization is not possible with out schema provided.
Results of the improved compatible serializer
A prototype that is implementing a solution number 2. described above has shown major improvements in the serialization. The simple test class was created:
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public class Test {
int value;
String name;
long longValue;
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The serialization was tested with values (5, "Ivan", 45545454). The new compatible implementation serialize this data into 19 bytes. The old (ineffective) Kryo compatible serializer serialize to 37 bytes. This is almost 100% more data needed by the old solution. As excepted the time needed for the serialization has significant decrease also, namely new implementation is 50%+ faster.
The new serializer was also compared to the Kryo serializer that does not provide the backward/forward compatibility, and that should have the best performance in general. This non-compatible Kyro serializer needs 50 micro seconds to serialize the object, while our new implementation needs 60 micro seconds. So the price that we pay for the forward/backward compatibility with new solution is around 20% slower serialization time. However, this is still improvement from the compatible serializer provided by Kyro.
Externalizable Interfaces
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