org.apache.tephra.distributed

Interface ThriftClientProvider

All Known Implementing Classes:

AbstractClientProvider, PooledClientProvider, SingleUseClientProvider, ThreadLocalClientProvider

public interface ThriftClientProvider

This interface is used to provide thrift tx service clients: there is only one (singleton) tx service per JVM, but many threads may use it concurrently. However, being a thrift client, it is not thread-safe. In order to avoid serializing all tx calls by synchronizing on the tx service client, we employ a pool of clients. But in different scenarios there are different strategies for pooling: If there are many short-lived threads, it is wise to have a shared pool between all threads. But if there are few long-lived threads, it may be better to have thread-local client for each thread. This interface provides an abstraction of the pooling strategy.

Method Summary

Modifier and Type	Method and Description
CloseableThriftClient	getCloseableClient() Retrieve an AutoCloseable wrapper around tx client for exclusive use by the current thread.
void	initialize() Initialize the provider.
void	returnClient(TransactionServiceThriftClient client) Release an tx client back to the provider's pool, if the client is valid.

Method Detail

initialize

void initialize()
         throws org.apache.thrift.TException

Initialize the provider. At this point, it should be verified that tx service is up and running and getClient() can create new clients when necessary.

Throws:

org.apache.thrift.TException

getCloseableClient

CloseableThriftClient getCloseableClient()
                                  throws org.apache.thrift.TException,
                                         TimeoutException,
                                         InterruptedException

Retrieve an AutoCloseable wrapper around tx client for exclusive use by the current thread. The client must be closed (returned) to the provider after use.

Returns:

an tx client, connected and fully functional

Throws:

org.apache.thrift.TException

TimeoutException

InterruptedException

returnClient

void returnClient(TransactionServiceThriftClient client)

Release an tx client back to the provider's pool, if the client is valid. If the client becomes disfunctional, for instance, due to a socket exception. The provider must make sure to close the client, and it must remove the client from its arsenal and be prepared to create a new client subsequently.

Parameters:

client - The client to return