17.5. Setting up the service persistence

The service persistence must be configured before making the initial call to any event-raising method or the connect method of the endpoint. All methods described in this section belong to the ServiceEndpoint class. To set SPL-1 (service persistence level 1) with a default capacity of 16 kilobytes, call the following method:

public void setPersistenceL1()

SPL-1 has a memory-based storage. If you want to set a different capacity of the storage, call the overload with a capacity parameter. Please note that the capacity of SPL-1 cannot be less than 4 kilobytes:

public void setPersistenceL1(long memoryBasedStorageCapacity)

The next method sets SPL-2 (service persistence level 2) with a default capacity of 1 megabyte:

public void setPersistenceL2()

The storage file will be created in the directory where the Softnet library file “softnet.jar” is located. The platform uses the following scheme for naming persistence storage files:

softnet.service.persistence_<serviceUuid>.ssp

The platform takes the value of <serviceUuid> from the service URI provided to the endpoint, which has the following format:

softnet-srv://<serviceUuid>@<serverAddress>

In order to set the persistence with a different capacity, or different location for the storage file, you have the following overload:

public void setPersistenceL2(
    String fileBasedStorageDirectory,
    long fileBasedStorageCapacity,
    long memoryBasedStorageCapacity)

The first parameter takes a directory for the storage file. If you want to leave the default location, specify null. The second parameter, fileBasedStorageCapacity, takes a capacity value. Again, if you want to leave the default value of 1 megabyte, specify 0. The minimum capacity of a file-based storage is 8 kilobytes. But the method also has a third parameter – memoryBasedStorageCapacity, which specifies the SPL-1 capacity. It is included because the platform switches the endpoint to SPL-1 if SPL-2 encounters an I/O error during storage operations. To leave the default capacity, which is 16 kilobytes, specify 0. If you want, for example, to set SPL-2 with default storage directory, but specify the capacity of SPL-2 as 4 megabytes and capacity of SPL-1 as 64 kilobytes, you’d make the following call:

serviceEndpoint.setPersistenceL2(null, 4194304, 65536);

Or, in a more elegant way:

serviceEndpoint.setPersistenceL2(
    null, 
    MemorySize.fromM(4), 
    MemorySize.fromK(64));

At last, we have the third overload of the setPersistenceL2 method designed to set a custom implementation of SPL-2:

public void setPersistenceL2(ServicePersistence servicePersistence, long memoryBasedStorageCapacity)

The first parameter is an implementation of the ServicePersistence interface, and the second – capacity of SPL-1.

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