/**
    * 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.hadoop.hbase.replication;
  
  import java.util.Map;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.hbase.client.Admin;
  import org.apache.hadoop.hbase.client.Get;
  import org.apache.hadoop.hbase.client.Put;
  import org.apache.hadoop.hbase.regionserver.HRegionServer;
  import org.apache.hadoop.hbase.replication.regionserver.ReplicationStatus;
  import org.apache.hadoop.hbase.testclassification.MediumTests;
  import org.apache.hadoop.hbase.testclassification.ReplicationTests;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.junit.Assert;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  
  @Category({ ReplicationTests.class, MediumTests.class })
  public class TestReplicationMetricsforUI extends TestReplicationBase {
  
    private static final byte[] qualName = Bytes.toBytes("q");
  
    @Test
    public void testReplicationMetrics() throws Exception {
      try (Admin hbaseAdmin = utility1.getConnection().getAdmin()) {
        Put p = new Put(Bytes.toBytes("starter"));
        p.addColumn(famName, qualName, Bytes.toBytes("value help to test replication delay"));
        htable1.put(p);
        // make sure replication done
        while (htable2.get(new Get(Bytes.toBytes("starter"))).size() == 0) {
          Thread.sleep(500);
        }
        // sleep 5 seconds to make sure timePassedAfterLastShippedOp > 2 * ageOfLastShippedOp
        Thread.sleep(5000);
        HRegionServer rs = utility1.getRSForFirstRegionInTable(tableName);
        Map<String, ReplicationStatus> metrics = rs.getWalGroupsReplicationStatus();
        Assert.assertEquals("metric size ", 1, metrics.size());
        for (Map.Entry<String, ReplicationStatus> metric : metrics.entrySet()) {
          Assert.assertEquals("peerId", PEER_ID2, metric.getValue().getPeerId());
          Assert.assertEquals("queue length", 1, metric.getValue().getQueueSize());
          Assert.assertEquals("replication delay", 0, metric.getValue().getReplicationDelay());
          long pos = metric.getValue().getCurrentPosition();
          // Semantics are a bit different in branch-1: If not started, pos will be -1
          if (pos == -1) {
            pos = 0;
          }
          Assert.assertTrue("current position should be >= 0, is " + pos, pos >= 0);
        }
        for (int i = 0; i < NB_ROWS_IN_BATCH; i++) {
          p = new Put(Bytes.toBytes("" + Integer.toString(i)));
          p.addColumn(famName, qualName, Bytes.toBytes("value help to test replication delay " + i));
          htable1.put(p);
        }
        while (htable2.get(new Get(Bytes.toBytes("" + Integer.toString(NB_ROWS_IN_BATCH - 1))))
            .size() == 0) {
          Thread.sleep(500);
        }
        rs = utility1.getRSForFirstRegionInTable(tableName);
        metrics = rs.getWalGroupsReplicationStatus();
        Path lastPath = null;
        for (Map.Entry<String, ReplicationStatus> metric : metrics.entrySet()) {
          lastPath = metric.getValue().getCurrentPath();
          Assert.assertEquals("peerId", PEER_ID2, metric.getValue().getPeerId());
          Assert.assertTrue("age of Last Shipped Op should be > 0 ",
            metric.getValue().getAgeOfLastShippedOp() > 0);
          long pos = metric.getValue().getCurrentPosition();
          Assert.assertTrue("current position should be >= 0, is " + pos, pos >= 0);
        }
  
        hbaseAdmin.rollWALWriter(rs.getServerName());
        p = new Put(Bytes.toBytes("trigger"));
        p.addColumn(famName, qualName, Bytes.toBytes("value help to test replication delay"));
        htable1.put(p);
        // make sure replication rolled to a new log
        while (htable2.get(new Get(Bytes.toBytes("trigger"))).size() == 0) {
          Thread.sleep(500);
        }
        // sleep 5 seconds to make sure timePassedAfterLastShippedOp > 2 * ageOfLastShippedOp
        Thread.sleep(5000);
        metrics = rs.getWalGroupsReplicationStatus();
        for (Map.Entry<String, ReplicationStatus> metric : metrics.entrySet()) {
          Assert.assertEquals("replication delay", 0, metric.getValue().getReplicationDelay());
          long pos = metric.getValue().getCurrentPosition();
         Assert.assertTrue("current position should be >= 0, is " + pos, pos >= 0);
         Assert.assertNotEquals("current path", lastPath, metric.getValue().getCurrentPath());
       }
     }
   }
 }