Dynamic Compact Serialization Implementation

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 and JSON's information does not travel on the network, and the object size on the network is reduced. As the object size decreases, network trips become faster, and eventually, the 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, the size of the serialized object is compact. In certain scenarios, the data size may be 10 times less than that of native serialization. Smaller serialized objects take less time to travel on the network thus, resulting in higher throughput. This also helps in reducing memory consumption on the cache server. In this manner, NCache achieves better performance - reducing time and cost. The small object size and fast network traffic increase 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 (the NCache Management Center or its Command Line Tools).

  • Selective Serialization: NCache allows selective serialization; you can select data members of a class that 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.

Implementing Compact Serialization for Object Type

To use Compact Serialization, object types that are to be compact serialized need to be configured through the NCache Management Center. NCache internally handles the 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 explicit implementation of the ICompactSerializable interface.

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

Important

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

Prerequisites

Creating DemoObject

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

    public DemoObject()
    { }

    public DemoObject(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 the NCache Management Center. There is another way for registering generic compact types through the "Generic Type Handler". With the 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 the GetGenericTypes method and return the desired generic types in the Type array. After this, deploy this class assembly to the NCache Management Center. The NCache Management Center will register all types populated in the Type array. A sample code is given below:

Important

If you want to mark a class for compact serialization that requires a 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

.NET: Alachisoft.NCache.Runtime namespace.