YARN-4025. Deal with byte representations of Longs in writer code. Contributed by Sangjin Lee and Vrushali C.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/HBaseTimelineReaderImpl.java

@@ -19,12 +19,9 @@ package org.apache.hadoop.yarn.server.timelineservice.storage;
 
 
 import java.io.IOException;
-import java.nio.charset.StandardCharsets;
-import java.util.Collection;
 import java.util.EnumSet;
 import java.util.HashMap;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.Map;
 import java.util.NavigableMap;
 import java.util.NavigableSet;
@@ -431,34 +428,36 @@ public class HBaseTimelineReaderImpl
     Map<String, Object> columns = prefix.readResults(result);
     if (isConfig) {
       for (Map.Entry<String, Object> column : columns.entrySet()) {
-        entity.addConfig(column.getKey(), column.getKey().toString());
+        entity.addConfig(column.getKey(), column.getValue().toString());
       }
     } else {
       entity.addInfo(columns);
     }
   }
 
+  /**
+   * Read events from the entity table or the application table. The column name
+   * is of the form "eventId=timestamp=infoKey" where "infoKey" may be omitted
+   * if there is no info associated with the event.
+   *
+   * See {@link EntityTable} and {@link ApplicationTable} for a more detailed
+   * schema description.
+   */
   private static void readEvents(TimelineEntity entity, Result result,
       boolean isApplication) throws IOException {
     Map<String, TimelineEvent> eventsMap = new HashMap<>();
-    Map<String, Object> eventsResult = isApplication ?
+    Map<?, Object> eventsResult = isApplication ?
-        ApplicationColumnPrefix.EVENT.readResults(result) :
+        ApplicationColumnPrefix.EVENT.
-        EntityColumnPrefix.EVENT.readResults(result);
+            readResultsHavingCompoundColumnQualifiers(result) :
-    for (Map.Entry<String,Object> eventResult : eventsResult.entrySet()) {
+        EntityColumnPrefix.EVENT.
-      Collection<String> tokens =
+            readResultsHavingCompoundColumnQualifiers(result);
-          Separator.VALUES.splitEncoded(eventResult.getKey());
+    for (Map.Entry<?, Object> eventResult : eventsResult.entrySet()) {
-      if (tokens.size() != 2 && tokens.size() != 3) {
+      byte[][] karr = (byte[][])eventResult.getKey();
-        throw new IOException(
+      // the column name is of the form "eventId=timestamp=infoKey"
-            "Invalid event column name: " + eventResult.getKey());
+      if (karr.length == 3) {
-      }
+        String id = Bytes.toString(karr[0]);
-      Iterator<String> idItr = tokens.iterator();
+        long ts = TimelineWriterUtils.invert(Bytes.toLong(karr[1]));
-      String id = idItr.next();
+        String key = Separator.VALUES.joinEncoded(id, Long.toString(ts));
-      String tsStr = idItr.next();
-      // TODO: timestamp is not correct via ser/des through UTF-8 string
-      Long ts =
-          TimelineWriterUtils.invert(Bytes.toLong(tsStr.getBytes(
-              StandardCharsets.UTF_8)));
-      String key = Separator.VALUES.joinEncoded(id, ts.toString());
         TimelineEvent event = eventsMap.get(key);
         if (event == null) {
           event = new TimelineEvent();
@@ -466,10 +465,15 @@ public class HBaseTimelineReaderImpl
           event.setTimestamp(ts);
           eventsMap.put(key, event);
         }
-      if (tokens.size() == 3) {
+        // handle empty info
-        String infoKey = idItr.next();
+        String infoKey = karr[2].length == 0 ? null : Bytes.toString(karr[2]);
+        if (infoKey != null) {
           event.addInfo(infoKey, eventResult.getValue());
         }
+      } else {
+        LOG.warn("incorrectly formatted column name: it will be discarded");
+        continue;
+      }
     }
     Set<TimelineEvent> eventsSet = new HashSet<>(eventsMap.values());
     entity.addEvents(eventsSet);

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/HBaseTimelineWriterImpl.java

@@ -300,25 +300,27 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
               byte[] compoundColumnQualifierBytes =
                   Separator.VALUES.join(columnQualifierWithTsBytes,
                       null);
-              String compoundColumnQualifier =
+              if (isApplication) {
-                  Bytes.toString(compoundColumnQualifierBytes);
+                ApplicationColumnPrefix.EVENT.store(rowKey, applicationTable,
+                    compoundColumnQualifierBytes, null,
+                      TimelineWriterUtils.EMPTY_BYTES);
+              } else {
                 EntityColumnPrefix.EVENT.store(rowKey, entityTable,
-                  compoundColumnQualifier, null, TimelineWriterUtils.EMPTY_BYTES);
+                    compoundColumnQualifierBytes, null,
+                    TimelineWriterUtils.EMPTY_BYTES);
+              }
             } else {
               for (Map.Entry<String, Object> info : eventInfo.entrySet()) {
                 // eventId?infoKey
                 byte[] compoundColumnQualifierBytes =
                     Separator.VALUES.join(columnQualifierWithTsBytes,
                         Bytes.toBytes(info.getKey()));
-                // convert back to string to avoid additional API on store.
-                String compoundColumnQualifier =
-                    Bytes.toString(compoundColumnQualifierBytes);
                 if (isApplication) {
                   ApplicationColumnPrefix.EVENT.store(rowKey, applicationTable,
-                    compoundColumnQualifier, null, info.getValue());
+                    compoundColumnQualifierBytes, null, info.getValue());
                 } else {
                   EntityColumnPrefix.EVENT.store(rowKey, entityTable,
-                    compoundColumnQualifier, null, info.getValue());
+                    compoundColumnQualifierBytes, null, info.getValue());
                 }
               } // for info: eventInfo
             }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/application/ApplicationColumnPrefix.java

@@ -101,6 +101,31 @@ public enum ApplicationColumnPrefix implements ColumnPrefix<ApplicationTable> {
     return columnPrefix;
   }
 
+  /*
+   * (non-Javadoc)
+   *
+   * @see
+   * org.apache.hadoop.yarn.server.timelineservice.storage.common.ColumnPrefix
+   * #store(byte[],
+   * org.apache.hadoop.yarn.server.timelineservice.storage.common.
+   * TypedBufferedMutator, java.lang.String, java.lang.Long, java.lang.Object)
+   */
+  public void store(byte[] rowKey,
+      TypedBufferedMutator<ApplicationTable> tableMutator, byte[] qualifier,
+      Long timestamp, Object inputValue) throws IOException {
+
+    // Null check
+    if (qualifier == null) {
+      throw new IOException("Cannot store column with null qualifier in "
+          + tableMutator.getName().getNameAsString());
+    }
+
+    byte[] columnQualifier =
+        ColumnHelper.getColumnQualifier(this.columnPrefixBytes, qualifier);
+
+    column.store(rowKey, tableMutator, columnQualifier, timestamp, inputValue);
+  }
+
   /*
    * (non-Javadoc)
    *
@@ -150,6 +175,21 @@ public enum ApplicationColumnPrefix implements ColumnPrefix<ApplicationTable> {
     return column.readResults(result, columnPrefixBytes);
   }
 
+  /**
+   * @param result from which to read columns
+   * @return the latest values of columns in the column family. The column
+   *         qualifier is returned as a list of parts, each part a byte[]. This
+   *         is to facilitate returning byte arrays of values that were not
+   *         Strings. If they can be treated as Strings, you should use
+   *         {@link #readResults(Result)} instead.
+   * @throws IOException
+   */
+  public Map<?, Object> readResultsHavingCompoundColumnQualifiers(Result result)
+      throws IOException {
+    return column.readResultsHavingCompoundColumnQualifiers(result,
+        columnPrefixBytes);
+  }
+
   /*
    * (non-Javadoc)
    *

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/application/ApplicationTable.java

@@ -57,12 +57,12 @@ import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimelineHBas
  * |            | infoValue                    | metricValue1 |              |
  * |            |                              | @timestamp2  |              |
  * |            | r!relatesToKey:              |              |              |
- * |            | id3?id4?id5                  |              |              |
+ * |            | id3=id4=id5                  |              |              |
  * |            |                              |              |              |
  * |            | s!isRelatedToKey:            |              |              |
- * |            | id7?id9?id6                  |              |              |
+ * |            | id7=id9=id6                  |              |              |
  * |            |                              |              |              |
- * |            | e!eventId?timestamp?infoKey: |              |              |
+ * |            | e!eventId=timestamp=infoKey: |              |              |
  * |            | eventInfoValue               |              |              |
  * |            |                              |              |              |
  * |            | flowVersion:                 |              |              |

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/common/ColumnHelper.java

@@ -24,6 +24,8 @@ import java.util.Map.Entry;
 import java.util.NavigableMap;
 import java.util.TreeMap;
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.client.Put;
 import org.apache.hadoop.hbase.client.Result;
@@ -37,6 +39,7 @@ import org.apache.hadoop.yarn.server.timeline.GenericObjectMapper;
  * @param <T> refers to the table.
  */
 public class ColumnHelper<T> {
+  private static final Log LOG = LogFactory.getLog(ColumnHelper.class);
 
   private final ColumnFamily<T> columnFamily;
 
@@ -143,6 +146,7 @@ public class ColumnHelper<T> {
             .entrySet()) {
           String columnName = null;
           if (columnPrefixBytes == null) {
+            LOG.info("null prefix was specified; returning all columns");
             // Decode the spaces we encoded in the column name.
             columnName = Separator.decode(entry.getKey(), Separator.SPACE);
           } else {
@@ -182,31 +186,42 @@ public class ColumnHelper<T> {
    * @param result from which to read columns
    * @param columnPrefixBytes optional prefix to limit columns. If null all
    *        columns are returned.
-   * @return the latest values of columns in the column family.
+   * @return the latest values of columns in the column family. This assumes
+   *         that the column name parts are all Strings by default. If the
+   *         column name parts should be treated natively and not be converted
+   *         back and forth from Strings, you should use
+   *         {@link #readResultsHavingCompoundColumnQualifiers(Result, byte[])}
+   *         instead.
    * @throws IOException
    */
-  public Map<String, Object> readResults(Result result, byte[] columnPrefixBytes)
+  public Map<String, Object> readResults(Result result,
-      throws IOException {
+      byte[] columnPrefixBytes) throws IOException {
     Map<String, Object> results = new HashMap<String, Object>();
 
     if (result != null) {
       Map<byte[], byte[]> columns = result.getFamilyMap(columnFamilyBytes);
       for (Entry<byte[], byte[]> entry : columns.entrySet()) {
-        if (entry.getKey() != null && entry.getKey().length > 0) {
+        byte[] columnKey = entry.getKey();
+        if (columnKey != null && columnKey.length > 0) {
 
           String columnName = null;
           if (columnPrefixBytes == null) {
+            LOG.info("null prefix was specified; returning all columns");
             // Decode the spaces we encoded in the column name.
-            columnName = Separator.decode(entry.getKey(), Separator.SPACE);
+            columnName = Separator.decode(columnKey, Separator.SPACE);
           } else {
             // A non-null prefix means columns are actually of the form
             // prefix!columnNameRemainder
             byte[][] columnNameParts =
-                Separator.QUALIFIERS.split(entry.getKey(), 2);
+                Separator.QUALIFIERS.split(columnKey, 2);
             byte[] actualColumnPrefixBytes = columnNameParts[0];
             if (Bytes.equals(columnPrefixBytes, actualColumnPrefixBytes)
                 && columnNameParts.length == 2) {
               // This is the prefix that we want
+              // if the column name is a compound qualifier
+              // with non string datatypes, the following decode will not
+              // work correctly since it considers all components to be String
+              // invoke the readResultsHavingCompoundColumnQualifiers function
               columnName = Separator.decode(columnNameParts[1]);
             }
           }
@@ -222,6 +237,56 @@ public class ColumnHelper<T> {
     return results;
   }
 
+  /**
+   * @param result from which to read columns
+   * @param columnPrefixBytes optional prefix to limit columns. If null all
+   *        columns are returned.
+   * @return the latest values of columns in the column family. If the column
+   *         prefix is null, the column qualifier is returned as Strings. For a
+   *         non-null column prefix bytes, the column qualifier is returned as
+   *         a list of parts, each part a byte[]. This is to facilitate
+   *         returning byte arrays of values that were not Strings.
+   * @throws IOException
+   */
+  public Map<?, Object> readResultsHavingCompoundColumnQualifiers(Result result,
+      byte[] columnPrefixBytes) throws IOException {
+    // handle the case where the column prefix is null
+    // it is the same as readResults() so simply delegate to that implementation
+    if (columnPrefixBytes == null) {
+      return readResults(result, null);
+    }
+
+    Map<byte[][], Object> results = new HashMap<byte[][], Object>();
+
+    if (result != null) {
+      Map<byte[], byte[]> columns = result.getFamilyMap(columnFamilyBytes);
+      for (Entry<byte[], byte[]> entry : columns.entrySet()) {
+        byte[] columnKey = entry.getKey();
+        if (columnKey != null && columnKey.length > 0) {
+          // A non-null prefix means columns are actually of the form
+          // prefix!columnNameRemainder
+          // with a compound column qualifier, we are presuming existence of a
+          // prefix
+          byte[][] columnNameParts = Separator.QUALIFIERS.split(columnKey, 2);
+          if (columnNameParts.length > 0) {
+            byte[] actualColumnPrefixBytes = columnNameParts[0];
+            if (Bytes.equals(columnPrefixBytes, actualColumnPrefixBytes)
+                && columnNameParts.length == 2) {
+              // This is the prefix that we want
+              byte[][] columnQualifierParts =
+                  Separator.VALUES.split(columnNameParts[1]);
+              Object value = GenericObjectMapper.read(entry.getValue());
+              // we return the columnQualifier in parts since we don't know
+              // which part is of which data type
+              results.put(columnQualifierParts, value);
+            }
+          }
+        }
+      } // for entry
+    }
+    return results;
+  }
+
   /**
    * @param columnPrefixBytes The byte representation for the column prefix.
    *          Should not contain {@link Separator#QUALIFIERS}.
@@ -247,4 +312,24 @@ public class ColumnHelper<T> {
     return columnQualifier;
   }
 
+  /**
+   * @param columnPrefixBytes The byte representation for the column prefix.
+   *          Should not contain {@link Separator#QUALIFIERS}.
+   * @param qualifier the byte representation for the remainder of the column.
+   * @return fully sanitized column qualifier that is a combination of prefix
+   *         and qualifier. If prefix is null, the result is simply the encoded
+   *         qualifier without any separator.
+   */
+  public static byte[] getColumnQualifier(byte[] columnPrefixBytes,
+      byte[] qualifier) {
+
+    if (columnPrefixBytes == null) {
+      return qualifier;
+    }
+
+    byte[] columnQualifier =
+        Separator.QUALIFIERS.join(columnPrefixBytes, qualifier);
+    return columnQualifier;
+  }
+
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/common/Separator.java

@@ -37,7 +37,7 @@ public enum Separator {
   /**
    * separator in values, and/or compound key/column qualifier fields.
    */
-  VALUES("?", "%1$"),
+  VALUES("=", "%1$"),
 
   /**
    * separator in values, often used to avoid having these in qualifiers and
@@ -299,12 +299,22 @@ public enum Separator {
    * up to a maximum of count items. This will naturally produce copied byte
    * arrays for each of the split segments.
    * @param source to be split
-   * @param limit on how many segments are supposed to be returned. Negative
+   * @param limit on how many segments are supposed to be returned. A
-   *          value indicates no limit on number of segments.
+   *          non-positive value indicates no limit on number of segments.
    * @return source split by this separator.
    */
   public byte[][] split(byte[] source, int limit) {
     return TimelineWriterUtils.split(source, this.bytes, limit);
   }
 
+  /**
+   * Splits the source array into multiple array segments using this separator,
+   * as many times as splits are found. This will naturally produce copied byte
+   * arrays for each of the split segments.
+   * @param source to be split
+   * @return source split by this separator.
+   */
+  public byte[][] split(byte[] source) {
+    return TimelineWriterUtils.split(source, this.bytes);
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/common/TimelineWriterUtils.java

@@ -33,6 +33,9 @@ public class TimelineWriterUtils {
   /** empty bytes */
   public static final byte[] EMPTY_BYTES = new byte[0];
 
+  /** indicator for no limits for splitting */
+  public static final int NO_LIMIT_SPLIT = -1;
+
   /**
    * Splits the source array into multiple array segments using the given
    * separator, up to a maximum of count items. This will naturally produce
@@ -45,7 +48,7 @@ public class TimelineWriterUtils {
    * @return byte[] array after splitting the source
    */
   public static byte[][] split(byte[] source, byte[] separator) {
-    return split(source, separator, -1);
+    return split(source, separator, NO_LIMIT_SPLIT);
   }
 
   /**
@@ -57,7 +60,7 @@ public class TimelineWriterUtils {
    *
    * @param source
    * @param separator
-   * @param limit a negative value indicates no limit on number of segments.
+   * @param limit a non-positive value indicates no limit on number of segments.
    * @return byte[][] after splitting the input source
    */
   public static byte[][] split(byte[] source, byte[] separator, int limit) {
@@ -81,7 +84,7 @@ public class TimelineWriterUtils {
    * separator byte array.
    */
   public static List<Range> splitRanges(byte[] source, byte[] separator) {
-    return splitRanges(source, separator, -1);
+    return splitRanges(source, separator, NO_LIMIT_SPLIT);
   }
 
   /**

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/entity/EntityColumnPrefix.java

@@ -126,6 +126,31 @@ public enum EntityColumnPrefix implements ColumnPrefix<EntityTable> {
     column.store(rowKey, tableMutator, columnQualifier, timestamp, inputValue);
   }
 
+  /*
+   * (non-Javadoc)
+   *
+   * @see
+   * org.apache.hadoop.yarn.server.timelineservice.storage.common.ColumnPrefix
+   * #store(byte[],
+   * org.apache.hadoop.yarn.server.timelineservice.storage.common.
+   * TypedBufferedMutator, java.lang.String, java.lang.Long, java.lang.Object)
+   */
+  public void store(byte[] rowKey,
+      TypedBufferedMutator<EntityTable> tableMutator, byte[] qualifier,
+      Long timestamp, Object inputValue) throws IOException {
+
+    // Null check
+    if (qualifier == null) {
+      throw new IOException("Cannot store column with null qualifier in "
+          + tableMutator.getName().getNameAsString());
+    }
+
+    byte[] columnQualifier =
+        ColumnHelper.getColumnQualifier(this.columnPrefixBytes, qualifier);
+
+    column.store(rowKey, tableMutator, columnQualifier, timestamp, inputValue);
+  }
+
   /*
    * (non-Javadoc)
    *
@@ -150,6 +175,21 @@ public enum EntityColumnPrefix implements ColumnPrefix<EntityTable> {
     return column.readResults(result, columnPrefixBytes);
   }
 
+  /**
+   * @param result from which to read columns
+   * @return the latest values of columns in the column family. The column
+   *         qualifier is returned as a list of parts, each part a byte[]. This
+   *         is to facilitate returning byte arrays of values that were not
+   *         Strings. If they can be treated as Strings, you should use
+   *         {@link #readResults(Result)} instead.
+   * @throws IOException
+   */
+  public Map<?, Object> readResultsHavingCompoundColumnQualifiers(Result result)
+          throws IOException {
+    return column.readResultsHavingCompoundColumnQualifiers(result,
+        columnPrefixBytes);
+  }
+
   /*
    * (non-Javadoc)
    *

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/entity/EntityTable.java

@@ -58,12 +58,12 @@ import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimelineHBas
  * |            | infoValue                    |              |              |
  * |            |                              |              |              |
  * |            | r!relatesToKey:              |              |              |
- * |            | id3?id4?id5                  |              |              |
+ * |            | id3=id4=id5                  |              |              |
  * |            |                              |              |              |
  * |            | s!isRelatedToKey             |              |              |
- * |            | id7?id9?id6                  |              |              |
+ * |            | id7=id9=id6                  |              |              |
  * |            |                              |              |              |
- * |            | e!eventId?timestamp?infoKey: |              |              |
+ * |            | e!eventId=timestamp=infoKey: |              |              |
  * |            | eventInfoValue               |              |              |
  * |            |                              |              |              |
  * |            | flowVersion:                 |              |              |

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/test/java/org/apache/hadoop/yarn/server/timelineservice/storage/TestHBaseTimelineWriterImpl.java

@@ -27,8 +27,8 @@ import java.util.EnumSet;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.NavigableMap;
+import java.util.NavigableSet;
 import java.util.Set;
 
 import org.apache.hadoop.conf.Configuration;
@@ -44,6 +44,7 @@ import org.apache.hadoop.yarn.api.records.ApplicationId;
 import org.apache.hadoop.yarn.api.records.timelineservice.ApplicationEntity;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntities;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity;
+import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntityType;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEvent;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineMetric;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineMetric.Type;
@@ -75,7 +76,7 @@ import org.junit.Test;
  * even if other records exist in the table. Use a different cluster name if
  * you add a new test.
  */
-public class TestHBaseTimelineWriterImpl {
+public class TestHBaseTimelineStorage {
 
   private static HBaseTestingUtility util;
 
@@ -101,8 +102,8 @@ public class TestHBaseTimelineWriterImpl {
     ApplicationEntity entity = new ApplicationEntity();
     String id = "hello";
     entity.setId(id);
-    Long cTime = 1425016501000L;
+    long cTime = 1425016501000L;
-    Long mTime = 1425026901000L;
+    long mTime = 1425026901000L;
     entity.setCreatedTime(cTime);
     entity.setModifiedTime(mTime);
 
@@ -197,19 +198,16 @@ public class TestHBaseTimelineWriterImpl {
 
       Number val =
           (Number) ApplicationColumn.CREATED_TIME.readResult(result);
-      Long cTime1 = val.longValue();
+      long cTime1 = val.longValue();
       assertEquals(cTime1, cTime);
 
       val = (Number) ApplicationColumn.MODIFIED_TIME.readResult(result);
-      Long mTime1 = val.longValue();
+      long mTime1 = val.longValue();
       assertEquals(mTime1, mTime);
 
       Map<String, Object> infoColumns =
           ApplicationColumnPrefix.INFO.readResults(result);
-      assertEquals(infoMap.size(), infoColumns.size());
+      assertEquals(infoMap, infoColumns);
-      for (String infoItem : infoMap.keySet()) {
-        assertEquals(infoMap.get(infoItem), infoColumns.get(infoItem));
-      }
 
       // Remember isRelatedTo is of type Map<String, Set<String>>
       for (String isRelatedToKey : isRelatedTo.keySet()) {
@@ -245,27 +243,15 @@ public class TestHBaseTimelineWriterImpl {
       // Configuration
       Map<String, Object> configColumns =
           ApplicationColumnPrefix.CONFIG.readResults(result);
-      assertEquals(conf.size(), configColumns.size());
+      assertEquals(conf, configColumns);
-      for (String configItem : conf.keySet()) {
-        assertEquals(conf.get(configItem), configColumns.get(configItem));
-      }
 
       NavigableMap<String, NavigableMap<Long, Number>> metricsResult =
           ApplicationColumnPrefix.METRIC.readResultsWithTimestamps(result);
 
       NavigableMap<Long, Number> metricMap = metricsResult.get(m1.getId());
-      // We got metrics back
+      assertEquals(metricValues, metricMap);
-      assertNotNull(metricMap);
-      // Same number of metrics as we wrote
-      assertEquals(metricValues.entrySet().size(), metricMap.entrySet().size());
-
-      // Iterate over original metrics and confirm that they are present
-      // here.
-      for (Entry<Long, Number> metricEntry : metricValues.entrySet()) {
-        assertEquals(metricEntry.getValue(),
-            metricMap.get(metricEntry.getKey()));
-      }
 
+      // read the timeline entity using the reader this time
       TimelineEntity e1 = hbr.getEntity(user, cluster, flow, runid, id,
           entity.getType(), entity.getId(),
           EnumSet.of(TimelineReader.Field.ALL));
@@ -274,6 +260,31 @@ public class TestHBaseTimelineWriterImpl {
           null, null, null, null, EnumSet.of(TimelineReader.Field.ALL));
       assertNotNull(e1);
       assertEquals(1, es1.size());
+
+      // verify attributes
+      assertEquals(id, e1.getId());
+      assertEquals(TimelineEntityType.YARN_APPLICATION.toString(),
+          e1.getType());
+      assertEquals(cTime, e1.getCreatedTime());
+      assertEquals(mTime, e1.getModifiedTime());
+      Map<String, Object> infoMap2 = e1.getInfo();
+      assertEquals(infoMap, infoMap2);
+
+      Map<String, Set<String>> isRelatedTo2 = e1.getIsRelatedToEntities();
+      assertEquals(isRelatedTo, isRelatedTo2);
+
+      Map<String, Set<String>> relatesTo2 = e1.getRelatesToEntities();
+      assertEquals(relatesTo, relatesTo2);
+
+      Map<String, String> conf2 = e1.getConfigs();
+      assertEquals(conf, conf2);
+
+      Set<TimelineMetric> metrics2 = e1.getMetrics();
+      assertEquals(metrics, metrics2);
+      for (TimelineMetric metric2 : metrics2) {
+        Map<Long, Number> metricValues2 = metric2.getValues();
+        assertEquals(metricValues, metricValues2);
+      }
     } finally {
       if (hbi != null) {
         hbi.stop();
@@ -294,8 +305,8 @@ public class TestHBaseTimelineWriterImpl {
     String type = "world";
     entity.setId(id);
     entity.setType(type);
-    Long cTime = 1425016501000L;
+    long cTime = 1425016501000L;
-    Long mTime = 1425026901000L;
+    long mTime = 1425026901000L;
     entity.setCreatedTime(cTime);
     entity.setModifiedTime(mTime);
 
@@ -396,20 +407,16 @@ public class TestHBaseTimelineWriterImpl {
           assertEquals(type, type1);
 
           Number val = (Number) EntityColumn.CREATED_TIME.readResult(result);
-          Long cTime1 = val.longValue();
+          long cTime1 = val.longValue();
           assertEquals(cTime1, cTime);
 
           val = (Number) EntityColumn.MODIFIED_TIME.readResult(result);
-          Long mTime1 = val.longValue();
+          long mTime1 = val.longValue();
           assertEquals(mTime1, mTime);
 
           Map<String, Object> infoColumns =
               EntityColumnPrefix.INFO.readResults(result);
-          assertEquals(infoMap.size(), infoColumns.size());
+          assertEquals(infoMap, infoColumns);
-          for (String infoItem : infoMap.keySet()) {
-            assertEquals(infoMap.get(infoItem),
-                infoColumns.get(infoItem));
-          }
 
           // Remember isRelatedTo is of type Map<String, Set<String>>
           for (String isRelatedToKey : isRelatedTo.keySet()) {
@@ -447,32 +454,19 @@ public class TestHBaseTimelineWriterImpl {
           // Configuration
           Map<String, Object> configColumns =
               EntityColumnPrefix.CONFIG.readResults(result);
-          assertEquals(conf.size(), configColumns.size());
+          assertEquals(conf, configColumns);
-          for (String configItem : conf.keySet()) {
-            assertEquals(conf.get(configItem), configColumns.get(configItem));
-          }
 
           NavigableMap<String, NavigableMap<Long, Number>> metricsResult =
               EntityColumnPrefix.METRIC.readResultsWithTimestamps(result);
 
           NavigableMap<Long, Number> metricMap = metricsResult.get(m1.getId());
-          // We got metrics back
+          assertEquals(metricValues, metricMap);
-          assertNotNull(metricMap);
-          // Same number of metrics as we wrote
-          assertEquals(metricValues.entrySet().size(), metricMap.entrySet()
-              .size());
-
-          // Iterate over original metrics and confirm that they are present
-          // here.
-          for (Entry<Long, Number> metricEntry : metricValues.entrySet()) {
-            assertEquals(metricEntry.getValue(),
-                metricMap.get(metricEntry.getKey()));
-          }
         }
       }
       assertEquals(1, rowCount);
       assertEquals(17, colCount);
 
+      // read the timeline entity using the reader this time
       TimelineEntity e1 = hbr.getEntity(user, cluster, flow, runid, appName,
           entity.getType(), entity.getId(),
           EnumSet.of(TimelineReader.Field.ALL));
@@ -481,6 +475,30 @@ public class TestHBaseTimelineWriterImpl {
           null, null, null, null, EnumSet.of(TimelineReader.Field.ALL));
       assertNotNull(e1);
       assertEquals(1, es1.size());
+
+      // verify attributes
+      assertEquals(id, e1.getId());
+      assertEquals(type, e1.getType());
+      assertEquals(cTime, e1.getCreatedTime());
+      assertEquals(mTime, e1.getModifiedTime());
+      Map<String, Object> infoMap2 = e1.getInfo();
+      assertEquals(infoMap, infoMap2);
+
+      Map<String, Set<String>> isRelatedTo2 = e1.getIsRelatedToEntities();
+      assertEquals(isRelatedTo, isRelatedTo2);
+
+      Map<String, Set<String>> relatesTo2 = e1.getRelatesToEntities();
+      assertEquals(relatesTo, relatesTo2);
+
+      Map<String, String> conf2 = e1.getConfigs();
+      assertEquals(conf, conf2);
+
+      Set<TimelineMetric> metrics2 = e1.getMetrics();
+      assertEquals(metrics, metrics2);
+      for (TimelineMetric metric2 : metrics2) {
+        Map<Long, Number> metricValues2 = metric2.getValues();
+        assertEquals(metricValues, metricValues2);
+      }
     } finally {
       if (hbi != null) {
         hbi.stop();
@@ -494,9 +512,9 @@ public class TestHBaseTimelineWriterImpl {
   }
 
   private boolean isRowKeyCorrect(byte[] rowKey, String cluster, String user,
-      String flow, Long runid, String appName, TimelineEntity te) {
+      String flow, long runid, String appName, TimelineEntity te) {
 
-    byte[][] rowKeyComponents = Separator.QUALIFIERS.split(rowKey, -1);
+    byte[][] rowKeyComponents = Separator.QUALIFIERS.split(rowKey);
 
     assertTrue(rowKeyComponents.length == 7);
     assertEquals(user, Bytes.toString(rowKeyComponents[0]));
@@ -511,9 +529,9 @@ public class TestHBaseTimelineWriterImpl {
   }
 
   private boolean isApplicationRowKeyCorrect(byte[] rowKey, String cluster,
-      String user, String flow, Long runid, String appName) {
+      String user, String flow, long runid, String appName) {
 
-    byte[][] rowKeyComponents = Separator.QUALIFIERS.split(rowKey, -1);
+    byte[][] rowKeyComponents = Separator.QUALIFIERS.split(rowKey);
 
     assertTrue(rowKeyComponents.length == 5);
     assertEquals(cluster, Bytes.toString(rowKeyComponents[0]));
@@ -530,7 +548,7 @@ public class TestHBaseTimelineWriterImpl {
     TimelineEvent event = new TimelineEvent();
     String eventId = ApplicationMetricsConstants.CREATED_EVENT_TYPE;
     event.setId(eventId);
-    Long expTs = 1436512802000L;
+    long expTs = 1436512802000L;
     event.setTimestamp(expTs);
     String expKey = "foo_event";
     Object expVal = "test";
@@ -577,24 +595,25 @@ public class TestHBaseTimelineWriterImpl {
       assertTrue(isApplicationRowKeyCorrect(row1, cluster, user, flow, runid,
           appName));
 
-      Map<String, Object> eventsResult =
+      Map<?, Object> eventsResult =
-          ApplicationColumnPrefix.EVENT.readResults(result);
+          ApplicationColumnPrefix.EVENT.
+              readResultsHavingCompoundColumnQualifiers(result);
       // there should be only one event
       assertEquals(1, eventsResult.size());
-      // key name for the event
+      for (Map.Entry<?, Object> e : eventsResult.entrySet()) {
-      byte[] compoundColumnQualifierBytes =
+        // the qualifier is a compound key
-          Separator.VALUES.join(Bytes.toBytes(eventId),
+        // hence match individual values
-              Bytes.toBytes(TimelineWriterUtils.invert(expTs)),
+        byte[][] karr = (byte[][])e.getKey();
-              Bytes.toBytes(expKey));
+        assertEquals(3, karr.length);
-      String valueKey = Bytes.toString(compoundColumnQualifierBytes);
+        assertEquals(eventId, Bytes.toString(karr[0]));
-      for (Map.Entry<String, Object> e : eventsResult.entrySet()) {
+        assertEquals(TimelineWriterUtils.invert(expTs), Bytes.toLong(karr[1]));
-        // the value key must match
+        assertEquals(expKey, Bytes.toString(karr[2]));
-        assertEquals(valueKey, e.getKey());
         Object value = e.getValue();
         // there should be only one timestamp and value
         assertEquals(expVal, value.toString());
       }
 
+      // read the timeline entity using the reader this time
       TimelineEntity e1 = hbr.getEntity(user, cluster, flow, runid, appName,
           entity.getType(), entity.getId(),
           EnumSet.of(TimelineReader.Field.ALL));
@@ -613,6 +632,21 @@ public class TestHBaseTimelineWriterImpl {
       assertEquals(1, es1.size());
       assertEquals(1, es2.size());
       assertEquals(es1, es2);
+
+      // check the events
+      NavigableSet<TimelineEvent> events = e1.getEvents();
+      // there should be only one event
+      assertEquals(1, events.size());
+      for (TimelineEvent e : events) {
+        assertEquals(eventId, e.getId());
+        assertEquals(expTs, e.getTimestamp());
+        Map<String,Object> info = e.getInfo();
+        assertEquals(1, info.size());
+        for (Map.Entry<String, Object> infoEntry : info.entrySet()) {
+          assertEquals(expKey, infoEntry.getKey());
+          assertEquals(expVal, infoEntry.getValue());
+        }
+      }
     } finally {
       if (hbi != null) {
         hbi.stop();
@@ -630,7 +664,7 @@ public class TestHBaseTimelineWriterImpl {
     TimelineEvent event = new TimelineEvent();
     String eventId = "foo_event_id";
     event.setId(eventId);
-    Long expTs = 1436512802000L;
+    long expTs = 1436512802000L;
     event.setTimestamp(expTs);
 
     final TimelineEntity entity = new TimelineEntity();
@@ -678,22 +712,21 @@ public class TestHBaseTimelineWriterImpl {
           assertTrue(isRowKeyCorrect(row1, cluster, user, flow, runid, appName,
               entity));
 
-          Map<String, Object> eventsResult =
+          Map<?, Object> eventsResult =
-              EntityColumnPrefix.EVENT.readResults(result);
+              EntityColumnPrefix.EVENT.
+                  readResultsHavingCompoundColumnQualifiers(result);
           // there should be only one event
           assertEquals(1, eventsResult.size());
-          // key name for the event
+          for (Map.Entry<?, Object> e : eventsResult.entrySet()) {
-          byte[] compoundColumnQualifierWithTsBytes =
+            // the qualifier is a compound key
-              Separator.VALUES.join(Bytes.toBytes(eventId),
+            // hence match individual values
-                  Bytes.toBytes(TimelineWriterUtils.invert(expTs)));
+            byte[][] karr = (byte[][])e.getKey();
-          byte[] compoundColumnQualifierBytes =
+            assertEquals(3, karr.length);
-              Separator.VALUES.join(compoundColumnQualifierWithTsBytes,
+            assertEquals(eventId, Bytes.toString(karr[0]));
-                  null);
+            assertEquals(TimelineWriterUtils.invert(expTs),
-          String valueKey = Bytes.toString(compoundColumnQualifierBytes);
+                Bytes.toLong(karr[1]));
-          for (Map.Entry<String, Object> e :
+            // key must be empty
-              eventsResult.entrySet()) {
+            assertEquals(0, karr[2].length);
-            // the column qualifier key must match
-            assertEquals(valueKey, e.getKey());
             Object value = e.getValue();
             // value should be empty
             assertEquals("", value.toString());
@@ -702,6 +735,7 @@ public class TestHBaseTimelineWriterImpl {
       }
       assertEquals(1, rowCount);
 
+      // read the timeline entity using the reader this time
       TimelineEntity e1 = hbr.getEntity(user, cluster, flow, runid, appName,
           entity.getType(), entity.getId(),
           EnumSet.of(TimelineReader.Field.ALL));
@@ -710,6 +744,17 @@ public class TestHBaseTimelineWriterImpl {
           null, null, null, null, EnumSet.of(TimelineReader.Field.ALL));
       assertNotNull(e1);
       assertEquals(1, es1.size());
+
+      // check the events
+      NavigableSet<TimelineEvent> events = e1.getEvents();
+      // there should be only one event
+      assertEquals(1, events.size());
+      for (TimelineEvent e : events) {
+        assertEquals(eventId, e.getId());
+        assertEquals(expTs, e.getTimestamp());
+        Map<String,Object> info = e.getInfo();
+        assertTrue(info == null || info.isEmpty());
+      }
     } finally {
       hbi.stop();
       hbi.close();