001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019package org.apache.hadoop.hdfs.inotify;
020
021import org.apache.hadoop.classification.InterfaceAudience;
022import org.apache.hadoop.classification.InterfaceStability;
023
024@InterfaceAudience.Public
025@InterfaceStability.Evolving
026public class MissingEventsException extends Exception {
027  private static final long serialVersionUID = 1L;
028
029  private long expectedTxid;
030  private long actualTxid;
031
032  public MissingEventsException() {}
033
034  public MissingEventsException(long expectedTxid, long actualTxid) {
035    this.expectedTxid = expectedTxid;
036    this.actualTxid = actualTxid;
037  }
038
039  public long getExpectedTxid() {
040    return expectedTxid;
041  }
042
043  public long getActualTxid() {
044    return actualTxid;
045  }
046
047  @Override
048  public String toString() {
049    return "We expected the next batch of events to start with transaction ID "
050        + expectedTxid + ", but it instead started with transaction ID " +
051        actualTxid + ". Most likely the intervening transactions were cleaned "
052        + "up as part of checkpointing.";
053  }
054}