Javadoc
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.