/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hive.hcatalog.streaming;
import org.apache.hadoop.security.UserGroupInformation;
/**
* Represents a connection to a HiveEndPoint. Used to acquire transaction batches.
* Note: the expectation is that there is at most 1 TransactionBatch outstanding for any given
* StreamingConnection. Violating this may result in "out of sequence response".
*/
public interface StreamingConnection {
/**
* Acquires a new batch of transactions from Hive.
* @param numTransactionsHint is a hint from client indicating how many transactions client needs.
* @param writer Used to write record. The same writer instance can
* be shared with another TransactionBatch (to the same endpoint)
* only after the first TransactionBatch has been closed.
* Writer will be closed when the TransactionBatch is closed.
* @return
* @throws ConnectionError
* @throws InvalidPartition
* @throws StreamingException
* @return a batch of transactions
*/
public TransactionBatch fetchTransactionBatch(int numTransactionsHint,
RecordWriter writer)
throws ConnectionError, StreamingException, InterruptedException;
/**
* Close connection
*/
public void close();
/**
* @return UserGroupInformation associated with this connection or {@code null} if there is none
*/
UserGroupInformation getUserGroupInformation();
}