HBASE-16592 unify delete request to use AsyncProcess. But the job is not done totally. As we still use rpc call for get, put, append, and increment. We only use AsyncProcess for batch requests. And I found one problem in HBASE-21365. The rpc call will throw a DoNotRetryException but AsyncProcess will wrap it with a new RetriesExhaustedWithDetailsException. It is not right. So I thought HTable.delete should use rpc call directly, it is same with get, put, append and increment request.