Dynamic Compact Serialization Implementation

Note

This feature is only available in NCache Enterprise Edition.

NCache stores application data in serialized form - it is serialized on the cache client before being added to the cache. Therefore, the data you add to the cache must also be marked as serializable. It supports native binary serialization for NCache client and it also has its own serialization framework called compact serialization which is fast and compact rather than native serialization. In native serialization of Java, all data of an object along with the entire type of information is serialized. In this way, the size of the object increases, whereas in compact serialization, the entire type of information does not travel on the network, and the object size which travels on the network is reduced. As the object size decreases, network trips become faster and eventually cost decreases hence increasing the overall application performance.

Compact serialization is also binary serialization which has the following benefits:

Compact Data Size

In NCache binary data, size of the serialized object is compact. In certain scenarios, data size may be 10 times less than that of native serialization. Smaller serialized objects take less time to travel on the network which thus results in higher throughput. This also helps in reducing memory consumption on the cache’s server. In this manner, NCache achieves better performance - reducing time and cost. The small object size and fast network traffic increases the application performance.

Faster than native serialization

Compact serialization is faster than native serialization as it does not rely as much on reflection as native serialization does. Native serialization uses reflection for attribute information. This reflection is avoided in NCache’s compact serialization. Type information for compact types is loaded only once when the cache is initialized, which reduces the overhead faced using native serialization. Benchmarks have shown that in certain used cases it is 5~10 times faster than native serialization.

No Code Change

There is no code change required to make a class compact serializable. The only step required is to configure your classes through management tools (NCache Manager or command line tools).

  • Selective Serialization: NCache allows selective serialization; you can select data members of a class which you want to mark as non-serializable. The excluded attribute of any cached object will either be null or will have a default value if assigned. This feature is useful in a scenario where for certain attributes, there is no need for caching, for example, connections object for database. By this selective serialization the process becomes even more efficient and more compact.

  • Granular Control over Compact Serialization: For this, you can implement ICompactSerializable. This interface gives you more fine grained control over compact serialization, you can control which data member to serialize and which to exclude according to your business needs.

  • Support for Native Serialization: NCache supports native binary serialization. Data is stored in serialized form in cache, client native serialization is supported for both .NET and Java clients of NCache.

Implement Compact Serialization for Custom Objects

To use Compact Serialization, object types that are to be compact serialized need to be configured through NCache Web Manager. NCache internally handles serialization/deserialization of registered classes and the user does not need to explicitly code for it.

Important

Class attributes need to be deserialized in the same order in which they have been serialized otherwise the serialized stream cannot be deserialized.

However, NCache also allows to explicitly implement ICompactSerializable interface.

To implement this interface, the custom object class needs to implement Serialize/Deserialize methods which will be called by NCache while serializing/deserializing this object. Sample code for implement this interface is given below:

Important

If you want to mark a class for compact serialization that requires parameterized constructor, make sure that the class contains a default constructor.

Prerequisites

Creating a Custom Object

public class CustomObject : ICompactSerializable
{
    private string _attribute1;
    private int _attribute2;
    private bool _attribute3;

    public CustomObject()
    { }

    public CustomObject(string attrib1, int attrib2, bool attrib3)
    {
        _attribute1 = attrib1;
        _attribute2 = attrib2;
        _attribute3 = attrib3;
    }

    #region ICompactSerializable Members

    public void Deserialize(CompactReader reader) {
            _attribute1 = reader.ReadObject() as string;
            _attribute2 = reader.ReadInt32();
            _attribute3 = reader.ReadBoolean();
    }

    public void Serialize(CompactWriter writer){
            writer.WriteObject(_attribute1);
            writer.Write(_attribute2);
            writer.Write(_attribute3);
    }

    #endregion
}

Implementing a Generic Type Handler

NCache also allows registering generic types in Compact Serialization. For this, each type needs to be registered through NCache Web Manager. There is another way for registering generic compact types through "Generic Type Handler". With Generic Type Handler, the user can add all the generic types at once by implementing the IGenericTypeProvider interface. This saves a lot of time and effort in case the user wants to register a large number of types.

Important

To utilize the interface, include the following namespace in your application: Alachisoft.NCache.Runtime.GenericTypesProvider

To implement this, the user needs to implement GetGenericTypes method and return the desired generic types in Type array. After this, deploy this class assembly to NCache Web Manager. NCache Web Manager will register all types populated in Type array. Sample code is given below:

Important

If you want to mark a class for compact serialization that requires parameterized constructor, make sure that the class contains a default constructor.

public class CustomGenericType<T, K, V>
{ }

public class SetGenerics : IGenericTypeProvider
{
    Type[] types = new Type[6];

    Type[] IGenericTypeProvider.GetGenericTypes()
    {
        types[0] = typeof(Dictionary<string, Customer>);
        types[1] = typeof(List<int>);
        types[2] = typeof(CustomGenericType<Employee, Product, Customer>);
        types[3] = typeof(CustomGenericType<Employee, Product, int>);
        types[4] = typeof(CustomGenericType<Employee, string, byte>);
        types[5] = typeof(CustomGenericType<string, Customer, bool>);

        return types;
    }

    public bool CheckIfSerializable(Type type, FieldInfo fieldInfo)
    {
        // implement logic
    }
}

Troubleshooting

Compact Serialization Exception

A Serialization exception may occur on the node where Compact Serializable types are not registered.

Workaround

Register Compact Serializable types on all the nodes in the cluster.

See Also

Aggregator
Registering Classes for Compact Serialization
MapReduce
Entry Processor