diff --git a/docs/content/ingestion/update-existing-data.md b/docs/content/ingestion/update-existing-data.md
index c1f7e54c939a..da3ae4507a62 100644
--- a/docs/content/ingestion/update-existing-data.md
+++ b/docs/content/ingestion/update-existing-data.md
@@ -76,7 +76,7 @@ For example
 
 #### `multi`
 
-This is a composing inputSpec to combine other inputSpecs. This inputSpec is used for delta ingestion. Please note that you can have only one `dataSource` as child of `multi` inputSpec.
+This is a composing inputSpec to combine other inputSpecs. This inputSpec is used for delta ingestion. You can also use a `multi` inputSpec to combine data from multiple dataSources. However, each particular dataSource can only be specified one time.
 Note that, "useNewAggs" must be set to default value false to support delta-ingestion.
 
 |Field|Type|Description|Required|
diff --git a/indexing-hadoop/src/main/java/io/druid/indexer/hadoop/DatasourceInputFormat.java b/indexing-hadoop/src/main/java/io/druid/indexer/hadoop/DatasourceInputFormat.java
index 437e3073e60e..0c28ced24e64 100644
--- a/indexing-hadoop/src/main/java/io/druid/indexer/hadoop/DatasourceInputFormat.java
+++ b/indexing-hadoop/src/main/java/io/druid/indexer/hadoop/DatasourceInputFormat.java
@@ -21,14 +21,14 @@
 
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Preconditions;
 import com.google.common.base.Supplier;
-import com.google.common.collect.Lists;
 import io.druid.data.input.InputRow;
 import io.druid.indexer.HadoopDruidIndexerConfig;
 import io.druid.indexer.JobHelper;
 import io.druid.java.util.common.ISE;
+import io.druid.java.util.common.StringUtils;
 import io.druid.java.util.common.logger.Logger;
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
@@ -56,82 +56,74 @@ public class DatasourceInputFormat extends InputFormat<NullWritable, InputRow>
 {
   private static final Logger logger = new Logger(DatasourceInputFormat.class);
 
-  public static final String CONF_INPUT_SEGMENTS = "druid.segments";
-  public static final String CONF_DRUID_SCHEMA = "druid.datasource.schema";
-  public static final String CONF_TRANSFORM_SPEC = "druid.datasource.transformSpec";
-  public static final String CONF_MAX_SPLIT_SIZE = "druid.datasource.split.max.size";
+  private static final String CONF_DATASOURCES = "druid.datasource.input.datasources";
+  private static final String CONF_SCHEMA = "druid.datasource.input.schema";
+  private static final String CONF_SEGMENTS = "druid.datasource.input.segments";
+  private static final String CONF_MAX_SPLIT_SIZE = "druid.datasource.input.split.max.size";
 
   @Override
   public List<InputSplit> getSplits(JobContext context) throws IOException
   {
     JobConf conf = new JobConf(context.getConfiguration());
 
-    String segmentsStr = Preconditions.checkNotNull(
-        conf.get(CONF_INPUT_SEGMENTS),
-        "No segments found to read"
-    );
-    List<WindowedDataSegment> segments = HadoopDruidIndexerConfig.JSON_MAPPER.readValue(
-        segmentsStr,
-        new TypeReference<List<WindowedDataSegment>>()
-        {
-        }
-    );
-    if (segments == null || segments.size() == 0) {
-      throw new ISE("No segments found to read");
-    }
+    List<String> dataSources = getDataSources(conf);
+    List<InputSplit> splits = new ArrayList<>();
 
-    // Note: log is splitted into two lines so that a new String is not generated to print it.
-    // segmentsStr could be quite large when re-indexing multiple months of data.
-    logger.info("Segment to read are...");
-    logger.info(segmentsStr);
+    for (String dataSource : dataSources) {
+      List<WindowedDataSegment> segments = getSegments(conf, dataSource);
+      if (segments == null || segments.size() == 0) {
+        throw new ISE("No segments found to read for dataSource[%s]", dataSource);
+      }
 
-    long maxSize = conf.getLong(CONF_MAX_SPLIT_SIZE, 0);
-    if (maxSize < 0) {
-      long totalSize = 0;
-      for (WindowedDataSegment segment : segments) {
-        totalSize += segment.getSegment().getSize();
+      // Note: Each segment is logged separately to avoid creating a huge String if we are loading lots of segments.
+      for (int i = 0; i < segments.size(); i++) {
+        final WindowedDataSegment segment = segments.get(i);
+        logger.info(
+            "Segment %,d/%,d for dataSource[%s] has identifier[%s], interval[%s]",
+            i,
+            segments.size(),
+            dataSource,
+            segment.getSegment().getIdentifier(),
+            segment.getInterval()
+        );
       }
-      int mapTask = conf.getNumMapTasks();
-      if (mapTask > 0) {
-        maxSize = totalSize / mapTask;
+
+      long maxSize = getMaxSplitSize(conf, dataSource);
+      if (maxSize < 0) {
+        long totalSize = 0;
+        for (WindowedDataSegment segment : segments) {
+          totalSize += segment.getSegment().getSize();
+        }
+        int mapTask = conf.getNumMapTasks();
+        if (mapTask > 0) {
+          maxSize = totalSize / mapTask;
+        }
       }
-    }
 
-    if (maxSize > 0) {
-      //combining is to happen, let us sort the segments list by size so that they
-      //are combined appropriately
-      Collections.sort(
-          segments,
-          new Comparator<WindowedDataSegment>()
-          {
-            @Override
-            public int compare(WindowedDataSegment s1, WindowedDataSegment s2)
-            {
-              return Long.compare(s1.getSegment().getSize(), s2.getSegment().getSize());
-            }
-          }
-      );
-    }
+      if (maxSize > 0) {
+        //combining is to happen, let us sort the segments list by size so that they
+        //are combined appropriately
+        segments.sort(Comparator.comparingLong(s -> s.getSegment().getSize()));
+      }
+
+      List<WindowedDataSegment> list = new ArrayList<>();
+      long size = 0;
 
-    List<InputSplit> splits = Lists.newArrayList();
+      org.apache.hadoop.mapred.InputFormat fio = supplier.get();
+      for (WindowedDataSegment segment : segments) {
+        if (size + segment.getSegment().getSize() > maxSize && size > 0) {
+          splits.add(toDataSourceSplit(list, fio, conf));
+          list = new ArrayList<>();
+          size = 0;
+        }
 
-    List<WindowedDataSegment> list = new ArrayList<>();
-    long size = 0;
+        list.add(segment);
+        size += segment.getSegment().getSize();
+      }
 
-    org.apache.hadoop.mapred.InputFormat fio = supplier.get();
-    for (WindowedDataSegment segment : segments) {
-      if (size + segment.getSegment().getSize() > maxSize && size > 0) {
+      if (list.size() > 0) {
         splits.add(toDataSourceSplit(list, fio, conf));
-        list = Lists.newArrayList();
-        size = 0;
       }
-
-      list.add(segment);
-      size += segment.getSegment().getSize();
-    }
-
-    if (list.size() > 0) {
-      splits.add(toDataSourceSplit(list, fio, conf));
     }
 
     logger.info("Number of splits [%d]", splits.size());
@@ -167,7 +159,7 @@ protected boolean isSplitable(FileSystem fs, Path file)
         protected FileStatus[] listStatus(JobConf job) throws IOException
         {
           // to avoid globbing which needs input path should be hadoop-compatible (':' is not acceptable in path, etc.)
-          List<FileStatus> statusList = Lists.newArrayList();
+          List<FileStatus> statusList = new ArrayList<>();
           for (Path path : FileInputFormat.getInputPaths(job)) {
             // load spec in segment points specifically zip file itself
             statusList.add(path.getFileSystem(job).getFileStatus(path));
@@ -250,4 +242,90 @@ static String[] getFrequentLocations(final Stream<String> locations)
         .map(Map.Entry::getKey)
         .toArray(String[]::new);
   }
+
+  public static List<String> getDataSources(final Configuration conf) throws IOException
+  {
+    final String currentDatasources = conf.get(CONF_DATASOURCES);
+
+    if (currentDatasources == null) {
+      return Collections.emptyList();
+    }
+
+    return HadoopDruidIndexerConfig.JSON_MAPPER.readValue(
+        currentDatasources,
+        new TypeReference<List<String>>() {}
+    );
+  }
+
+  public static DatasourceIngestionSpec getIngestionSpec(final Configuration conf, final String dataSource)
+      throws IOException
+  {
+    final String specString = conf.get(StringUtils.format("%s.%s", CONF_SCHEMA, dataSource));
+    if (specString == null) {
+      throw new NullPointerException(StringUtils.format("null spec for dataSource[%s]", dataSource));
+    }
+
+    final DatasourceIngestionSpec spec = HadoopDruidIndexerConfig.JSON_MAPPER.readValue(
+        specString,
+        DatasourceIngestionSpec.class
+    );
+
+    if (spec.getDimensions() == null || spec.getDimensions().size() == 0) {
+      throw new ISE("load schema does not have dimensions");
+    }
+
+    if (spec.getMetrics() == null || spec.getMetrics().size() == 0) {
+      throw new ISE("load schema does not have metrics");
+    }
+
+    return spec;
+  }
+
+  public static List<WindowedDataSegment> getSegments(final Configuration conf, final String dataSource)
+      throws IOException
+  {
+    return HadoopDruidIndexerConfig.JSON_MAPPER.readValue(
+        conf.get(StringUtils.format("%s.%s", CONF_SEGMENTS, dataSource)),
+        new TypeReference<List<WindowedDataSegment>>() {}
+    );
+  }
+
+  public static long getMaxSplitSize(final Configuration conf, final String dataSource)
+  {
+    return conf.getLong(StringUtils.format("%s.%s", CONF_MAX_SPLIT_SIZE, dataSource), 0L);
+  }
+
+  public static void addDataSource(
+      final Configuration conf,
+      final DatasourceIngestionSpec spec,
+      final List<WindowedDataSegment> segments,
+      final long maxSplitSize
+  ) throws IOException
+  {
+    final List<String> dataSources = getDataSources(conf);
+
+    if (dataSources.contains(spec.getDataSource())) {
+      throw new ISE("Oops, cannot load the same dataSource twice!");
+    }
+
+    final List<String> newDataSources = new ArrayList<>(dataSources);
+    newDataSources.add(spec.getDataSource());
+
+    conf.set(CONF_DATASOURCES, HadoopDruidIndexerConfig.JSON_MAPPER.writeValueAsString(newDataSources));
+
+    conf.set(
+        StringUtils.format("%s.%s", CONF_SCHEMA, spec.getDataSource()),
+        HadoopDruidIndexerConfig.JSON_MAPPER.writeValueAsString(spec)
+    );
+
+    conf.set(
+        StringUtils.format("%s.%s", CONF_SEGMENTS, spec.getDataSource()),
+        HadoopDruidIndexerConfig.JSON_MAPPER.writeValueAsString(segments)
+    );
+
+    conf.set(
+        StringUtils.format("%s.%s", CONF_MAX_SPLIT_SIZE, spec.getDataSource()),
+        String.valueOf(maxSplitSize)
+    );
+  }
 }
diff --git a/indexing-hadoop/src/main/java/io/druid/indexer/hadoop/DatasourceRecordReader.java b/indexing-hadoop/src/main/java/io/druid/indexer/hadoop/DatasourceRecordReader.java
index 74220adc6b65..12170be38dc0 100644
--- a/indexing-hadoop/src/main/java/io/druid/indexer/hadoop/DatasourceRecordReader.java
+++ b/indexing-hadoop/src/main/java/io/druid/indexer/hadoop/DatasourceRecordReader.java
@@ -19,10 +19,9 @@
 
 package io.druid.indexer.hadoop;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.common.base.Function;
-import com.google.common.base.Preconditions;
 import com.google.common.base.Throwables;
+import com.google.common.collect.Iterators;
 import com.google.common.collect.Lists;
 import com.google.common.io.Closeables;
 import com.google.common.io.Files;
@@ -30,14 +29,12 @@
 import io.druid.data.input.Row;
 import io.druid.indexer.HadoopDruidIndexerConfig;
 import io.druid.indexer.JobHelper;
-import io.druid.java.util.common.ISE;
 import io.druid.java.util.common.logger.Logger;
 import io.druid.segment.QueryableIndex;
 import io.druid.segment.QueryableIndexStorageAdapter;
 import io.druid.segment.realtime.firehose.IngestSegmentFirehose;
 import io.druid.segment.realtime.firehose.WindowedStorageAdapter;
 import org.apache.commons.io.FileUtils;
-import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.io.NullWritable;
 import org.apache.hadoop.mapreduce.InputSplit;
@@ -63,11 +60,18 @@ public class DatasourceRecordReader extends RecordReader<NullWritable, InputRow>
   private int numRows;
 
   @Override
-  public void initialize(InputSplit split, final TaskAttemptContext context)
+  public void initialize(InputSplit split, final TaskAttemptContext context) throws IOException
   {
-    spec = readAndVerifyDatasourceIngestionSpec(context.getConfiguration(), HadoopDruidIndexerConfig.JSON_MAPPER);
-
     List<WindowedDataSegment> segments = ((DatasourceInputSplit) split).getSegments();
+    String dataSource = Iterators.getOnlyElement(
+        segments.stream()
+                .map(s -> s.getSegment().getDataSource())
+                .distinct()
+                .iterator()
+    );
+
+    spec = DatasourceInputFormat.getIngestionSpec(context.getConfiguration(), dataSource);
+    logger.info("load schema [%s]", spec);
 
     List<WindowedStorageAdapter> adapters = Lists.transform(
         segments,
@@ -160,27 +164,4 @@ public void close() throws IOException
       FileUtils.deleteDirectory(dir);
     }
   }
-
-  private DatasourceIngestionSpec readAndVerifyDatasourceIngestionSpec(Configuration config, ObjectMapper jsonMapper)
-  {
-    try {
-      String schema = Preconditions.checkNotNull(config.get(DatasourceInputFormat.CONF_DRUID_SCHEMA), "null schema");
-      logger.info("load schema [%s]", schema);
-
-      DatasourceIngestionSpec spec = jsonMapper.readValue(schema, DatasourceIngestionSpec.class);
-
-      if (spec.getDimensions() == null || spec.getDimensions().size() == 0) {
-        throw new ISE("load schema does not have dimensions");
-      }
-
-      if (spec.getMetrics() == null || spec.getMetrics().size() == 0) {
-        throw new ISE("load schema does not have metrics");
-      }
-
-      return spec;
-    }
-    catch (IOException ex) {
-      throw new RuntimeException("couldn't load segment load spec", ex);
-    }
-  }
 }
diff --git a/indexing-hadoop/src/main/java/io/druid/indexer/path/DatasourcePathSpec.java b/indexing-hadoop/src/main/java/io/druid/indexer/path/DatasourcePathSpec.java
index d7cdf89cfbc9..7a9da80115eb 100644
--- a/indexing-hadoop/src/main/java/io/druid/indexer/path/DatasourcePathSpec.java
+++ b/indexing-hadoop/src/main/java/io/druid/indexer/path/DatasourcePathSpec.java
@@ -190,11 +190,8 @@ public Iterable<String> apply(WindowedDataSegment dataSegment)
         config.getSchema().getDataSchema().getTransformSpec()
     );
 
-    job.getConfiguration().set(DatasourceInputFormat.CONF_DRUID_SCHEMA, mapper.writeValueAsString(updatedIngestionSpec));
-    job.getConfiguration().set(DatasourceInputFormat.CONF_INPUT_SEGMENTS, mapper.writeValueAsString(segments));
-    job.getConfiguration().set(DatasourceInputFormat.CONF_MAX_SPLIT_SIZE, String.valueOf(maxSplitSize));
+    DatasourceInputFormat.addDataSource(job.getConfiguration(), updatedIngestionSpec, segments, maxSplitSize);
     MultipleInputs.addInputPath(job, new Path("/dummy/tobe/ignored"), DatasourceInputFormat.class);
-
     return job;
   }
 
diff --git a/indexing-hadoop/src/test/java/io/druid/indexer/BatchDeltaIngestionTest.java b/indexing-hadoop/src/test/java/io/druid/indexer/BatchDeltaIngestionTest.java
index b7bb444c1cc7..3970e23fc1b7 100644
--- a/indexing-hadoop/src/test/java/io/druid/indexer/BatchDeltaIngestionTest.java
+++ b/indexing-hadoop/src/test/java/io/druid/indexer/BatchDeltaIngestionTest.java
@@ -119,7 +119,7 @@ public void testReindexing() throws Exception
             "ingestionSpec",
             ImmutableMap.of(
                 "dataSource",
-                "xyz",
+                "testds",
                 "interval",
                 INTERVAL_FULL
             ),
@@ -180,7 +180,7 @@ public void testReindexingWithNewAggregators() throws Exception
         "ingestionSpec",
         ImmutableMap.of(
             "dataSource",
-            "xyz",
+            "testds",
             "interval",
             INTERVAL_FULL
         ),
@@ -239,7 +239,7 @@ public void testReindexingWithPartialWindow() throws Exception
             "ingestionSpec",
             ImmutableMap.of(
                 "dataSource",
-                "xyz",
+                "testds",
                 "interval",
                 INTERVAL_FULL
             ),
@@ -314,7 +314,7 @@ public void testDeltaIngestion() throws Exception
                     "ingestionSpec",
                     ImmutableMap.of(
                         "dataSource",
-                        "xyz",
+                        "testds",
                         "interval",
                         INTERVAL_FULL
                     ),
diff --git a/indexing-hadoop/src/test/java/io/druid/indexer/hadoop/DatasourceInputFormatTest.java b/indexing-hadoop/src/test/java/io/druid/indexer/hadoop/DatasourceInputFormatTest.java
index 1b4af099662f..1f9ab9b9a9b5 100644
--- a/indexing-hadoop/src/test/java/io/druid/indexer/hadoop/DatasourceInputFormatTest.java
+++ b/indexing-hadoop/src/test/java/io/druid/indexer/hadoop/DatasourceInputFormatTest.java
@@ -23,14 +23,16 @@
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Iterables;
+import com.google.common.collect.Iterators;
 import com.google.common.collect.Maps;
 import com.google.common.collect.Sets;
 import com.google.common.io.Files;
 import io.druid.indexer.JobHelper;
-import io.druid.jackson.DefaultObjectMapper;
 import io.druid.java.util.common.Intervals;
+import io.druid.java.util.common.JodaUtils;
 import io.druid.timeline.DataSegment;
 import io.druid.timeline.partition.NoneShardSpec;
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.BlockLocation;
 import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.FileSystem;
@@ -51,8 +53,10 @@
 import java.io.File;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 /**
@@ -62,7 +66,8 @@ public class DatasourceInputFormatTest
   @Rule
   public final TemporaryFolder temporaryFolder = new TemporaryFolder();
 
-  private List<WindowedDataSegment> segments;
+  private List<WindowedDataSegment> segments1;
+  private List<WindowedDataSegment> segments2;
   private List<LocatedFileStatus> locations;
   private JobConf config;
   private JobContext context;
@@ -70,7 +75,7 @@ public class DatasourceInputFormatTest
   @Before
   public void setUp() throws Exception
   {
-    segments = ImmutableList.of(
+    segments1 = ImmutableList.of(
         WindowedDataSegment.of(
             new DataSegment(
                 "test1",
@@ -89,7 +94,7 @@ public void setUp() throws Exception
         ),
         WindowedDataSegment.of(
             new DataSegment(
-                "test2",
+                "test1",
                 Intervals.of("2050/3000"),
                 "ver",
                 ImmutableMap.<String, Object>of(
@@ -105,7 +110,7 @@ public void setUp() throws Exception
         ),
         WindowedDataSegment.of(
             new DataSegment(
-                "test3",
+                "test1",
                 Intervals.of("2030/3000"),
                 "ver",
                 ImmutableMap.<String, Object>of(
@@ -121,9 +126,29 @@ public void setUp() throws Exception
         )
     );
 
-    Path path1 = new Path(JobHelper.getURIFromSegment(segments.get(0).getSegment()));
-    Path path2 = new Path(JobHelper.getURIFromSegment(segments.get(1).getSegment()));
-    Path path3 = new Path(JobHelper.getURIFromSegment(segments.get(2).getSegment()));
+    segments2 = ImmutableList.of(
+        WindowedDataSegment.of(
+            new DataSegment(
+                "test2",
+                Intervals.of("2000/3000"),
+                "ver",
+                ImmutableMap.<String, Object>of(
+                    "type", "local",
+                    "path", "/tmp/index4.zip"
+                ),
+                ImmutableList.of("host"),
+                ImmutableList.of("visited_sum", "unique_hosts"),
+                NoneShardSpec.instance(),
+                9,
+                2
+            )
+        )
+    );
+
+    Path path1 = new Path(JobHelper.getURIFromSegment(segments1.get(0).getSegment()));
+    Path path2 = new Path(JobHelper.getURIFromSegment(segments1.get(1).getSegment()));
+    Path path3 = new Path(JobHelper.getURIFromSegment(segments1.get(2).getSegment()));
+    Path path4 = new Path(JobHelper.getURIFromSegment(segments2.get(0).getSegment()));
 
     // dummy locations for test
     locations = ImmutableList.of(
@@ -140,7 +165,7 @@ public void setUp() throws Exception
                 new BlockLocation(null, new String[]{"s1", "s2"}, 0, 1000),
                 new BlockLocation(null, new String[]{"s1", "s3"}, 1000, 1200),
                 new BlockLocation(null, new String[]{"s2", "s3"}, 2200, 1100),
-                new BlockLocation(null, new String[]{"s1", "s2"}, 3300, 700),
+                new BlockLocation(null, new String[]{"s1", "s2"}, 3300, 700)
             }
         ),
         new LocatedFileStatus(
@@ -148,21 +173,56 @@ public void setUp() throws Exception
             new BlockLocation[]{
                 new BlockLocation(null, new String[]{"s2", "s3"}, 0, 500)
             }
+        ),
+        new LocatedFileStatus(
+            500, false, 0, 0, 0, 0, null, null, null, null, path4,
+            new BlockLocation[]{
+                new BlockLocation(null, new String[]{"s2", "s3"}, 0, 500)
+            }
         )
     );
 
-    config = new JobConf();
-    config.set(
-        DatasourceInputFormat.CONF_INPUT_SEGMENTS,
-        new DefaultObjectMapper().writeValueAsString(segments)
-    );
-
+    config = populateConfiguration(new JobConf(), segments1, 0);
     context = EasyMock.createMock(JobContext.class);
     EasyMock.expect(context.getConfiguration()).andReturn(config);
     EasyMock.replay(context);
   }
 
-  private Supplier<InputFormat> testFormatter = new Supplier<InputFormat>() {
+  private static <T extends Configuration> T populateConfiguration(
+      final T conf,
+      final List<WindowedDataSegment> segments,
+      final long maxSplitSize
+  )
+      throws IOException
+  {
+    DatasourceInputFormat.addDataSource(
+        conf,
+        new DatasourceIngestionSpec(
+            Iterators.getOnlyElement(segments.stream().map(s -> s.getSegment().getDataSource()).distinct().iterator()),
+            null,
+            Collections.singletonList(
+                JodaUtils.umbrellaInterval(
+                    segments.stream()
+                            .map(WindowedDataSegment::getInterval)
+                            .collect(Collectors.toList())
+                )
+            ),
+            null,
+            null,
+            null,
+            null,
+            false,
+            null
+        ),
+        segments,
+        maxSplitSize
+    );
+
+    return conf;
+  }
+
+  private Supplier<InputFormat> testFormatter = new Supplier<InputFormat>()
+  {
     @Override
     public InputFormat get()
     {
@@ -202,25 +262,47 @@ public void testGetSplitsNoCombining() throws Exception
     DatasourceInputFormat inputFormat = new DatasourceInputFormat().setSupplier(testFormatter);
     List<InputSplit> splits = inputFormat.getSplits(context);
 
-    Assert.assertEquals(segments.size(), splits.size());
-    for (int i = 0; i < segments.size(); i++) {
+    Assert.assertEquals(segments1.size(), splits.size());
+    for (int i = 0; i < segments1.size(); i++) {
       DatasourceInputSplit split = (DatasourceInputSplit) splits.get(i);
-      Assert.assertEquals(segments.get(i), split.getSegments().get(0));
+      Assert.assertEquals(segments1.get(i), split.getSegments().get(0));
     }
-    Assert.assertArrayEquals(new String[] {"s1", "s2"}, splits.get(0).getLocations());
-    Assert.assertArrayEquals(new String[] {"s1", "s2"}, splits.get(1).getLocations());
-    Assert.assertArrayEquals(new String[] {"s2", "s3"}, splits.get(2).getLocations());
+    Assert.assertArrayEquals(new String[]{"s1", "s2"}, splits.get(0).getLocations());
+    Assert.assertArrayEquals(new String[]{"s1", "s2"}, splits.get(1).getLocations());
+    Assert.assertArrayEquals(new String[]{"s2", "s3"}, splits.get(2).getLocations());
+  }
+
+  @Test
+  public void testGetSplitsTwoDataSources() throws Exception
+  {
+    config.clear();
+    populateConfiguration(populateConfiguration(config, segments1, 999999), segments2, 999999);
+    List<InputSplit> splits = new DatasourceInputFormat().setSupplier(testFormatter).getSplits(context);
+
+    Assert.assertEquals(2, splits.size());
+    Assert.assertEquals(
+        Sets.newHashSet(segments1),
+        Sets.newHashSet((((DatasourceInputSplit) splits.get(0)).getSegments()))
+    );
+    Assert.assertEquals(
+        Sets.newHashSet(segments2),
+        Sets.newHashSet((((DatasourceInputSplit) splits.get(1)).getSegments()))
+    );
+
+    Assert.assertArrayEquals(new String[]{"s2", "s1", "s3"}, splits.get(0).getLocations());
+    Assert.assertArrayEquals(new String[]{"s2", "s3"}, splits.get(1).getLocations());
   }
 
   @Test
   public void testGetSplitsAllCombined() throws Exception
   {
-    config.set(DatasourceInputFormat.CONF_MAX_SPLIT_SIZE, "999999");
+    config.clear();
+    populateConfiguration(config, segments1, 999999);
     List<InputSplit> splits = new DatasourceInputFormat().setSupplier(testFormatter).getSplits(context);
 
     Assert.assertEquals(1, splits.size());
     Assert.assertEquals(
-        Sets.newHashSet(segments),
+        Sets.newHashSet(segments1),
         Sets.newHashSet((((DatasourceInputSplit) splits.get(0)).getSegments()))
     );
 
@@ -230,19 +312,20 @@ public void testGetSplitsAllCombined() throws Exception
   @Test
   public void testGetSplitsCombineInTwo() throws Exception
   {
-    config.set(DatasourceInputFormat.CONF_MAX_SPLIT_SIZE, "6");
+    config.clear();
+    populateConfiguration(config, segments1, 6);
     List<InputSplit> splits = new DatasourceInputFormat().setSupplier(testFormatter).getSplits(context);
 
     Assert.assertEquals(2, splits.size());
 
     Assert.assertEquals(
-        Sets.newHashSet(segments.get(0), segments.get(2)),
+        Sets.newHashSet(segments1.get(0), segments1.get(2)),
         Sets.newHashSet((((DatasourceInputSplit) splits.get(0)).getSegments()))
     );
     Assert.assertArrayEquals(new String[]{"s2", "s1", "s3"}, splits.get(0).getLocations());
 
     Assert.assertEquals(
-        Sets.newHashSet(segments.get(1)),
+        Sets.newHashSet(segments1.get(1)),
         Sets.newHashSet((((DatasourceInputSplit) splits.get(1)).getSegments()))
     );
     Assert.assertArrayEquals(new String[]{"s1", "s2"}, splits.get(1).getLocations());
@@ -251,26 +334,27 @@ public void testGetSplitsCombineInTwo() throws Exception
   @Test
   public void testGetSplitsCombineCalculated() throws Exception
   {
-    config.set(DatasourceInputFormat.CONF_MAX_SPLIT_SIZE, "-1");
+    config.clear();
+    populateConfiguration(config, segments1, -1);
     config.setNumMapTasks(3);
     List<InputSplit> splits = new DatasourceInputFormat().setSupplier(testFormatter).getSplits(context);
 
     Assert.assertEquals(3, splits.size());
 
     Assert.assertEquals(
-        Sets.newHashSet(segments.get(0)),
+        Sets.newHashSet(segments1.get(0)),
         Sets.newHashSet((((DatasourceInputSplit) splits.get(0)).getSegments()))
     );
     Assert.assertArrayEquals(new String[]{"s1", "s2"}, splits.get(0).getLocations());
 
     Assert.assertEquals(
-        Sets.newHashSet(segments.get(2)),
+        Sets.newHashSet(segments1.get(2)),
         Sets.newHashSet((((DatasourceInputSplit) splits.get(1)).getSegments()))
     );
     Assert.assertArrayEquals(new String[]{"s2", "s3"}, splits.get(1).getLocations());
 
     Assert.assertEquals(
-        Sets.newHashSet(segments.get(1)),
+        Sets.newHashSet(segments1.get(1)),
         Sets.newHashSet((((DatasourceInputSplit) splits.get(2)).getSegments()))
     );
     Assert.assertArrayEquals(new String[]{"s1", "s2"}, splits.get(2).getLocations());
@@ -302,12 +386,7 @@ public void testGetSplitsUsingDefaultSupplier() throws Exception
         )
     );
 
-    final JobConf myConfig = new JobConf();
-    myConfig.set(
-        DatasourceInputFormat.CONF_INPUT_SEGMENTS,
-        new DefaultObjectMapper().writeValueAsString(mySegments)
-    );
-
+    final JobConf myConfig = populateConfiguration(new JobConf(), mySegments, 0L);
     final JobContext myContext = EasyMock.createMock(JobContext.class);
     EasyMock.expect(myContext.getConfiguration()).andReturn(myConfig);
     EasyMock.replay(myContext);
@@ -367,7 +446,7 @@ public void testGetLocationsInputFormatException() throws IOException
 
     Assert.assertEquals(
         0,
-        DatasourceInputFormat.getLocations(segments.subList(0, 1), fio, config).count()
+        DatasourceInputFormat.getLocations(segments1.subList(0, 1), fio, config).count()
     );
   }
 
@@ -383,7 +462,7 @@ public void testGetLocationsSplitException() throws IOException
     );
 
     EasyMock.expect(fio.getSplits(config, 1)).andReturn(
-        new org.apache.hadoop.mapred.InputSplit[] {split}
+        new org.apache.hadoop.mapred.InputSplit[]{split}
     );
     EasyMock.expect(split.getLocations()).andThrow(new IOException("testing"));
 
@@ -391,7 +470,7 @@ public void testGetLocationsSplitException() throws IOException
 
     Assert.assertEquals(
         0,
-        DatasourceInputFormat.getLocations(segments.subList(0, 1), fio, config).count()
+        DatasourceInputFormat.getLocations(segments1.subList(0, 1), fio, config).count()
     );
   }
 
@@ -407,25 +486,25 @@ public void testGetLocations() throws IOException
     );
 
     EasyMock.expect(fio.getSplits(config, 1)).andReturn(
-        new org.apache.hadoop.mapred.InputSplit[] {split}
+        new org.apache.hadoop.mapred.InputSplit[]{split}
     );
-    EasyMock.expect(split.getLocations()).andReturn(new String[] {"s1", "s2"});
+    EasyMock.expect(split.getLocations()).andReturn(new String[]{"s1", "s2"});
 
     EasyMock.expect(fio.getSplits(config, 1)).andReturn(
-        new org.apache.hadoop.mapred.InputSplit[] {split}
+        new org.apache.hadoop.mapred.InputSplit[]{split}
     );
-    EasyMock.expect(split.getLocations()).andReturn(new String[] {"s3"});
+    EasyMock.expect(split.getLocations()).andReturn(new String[]{"s3"});
 
     EasyMock.expect(fio.getSplits(config, 1)).andReturn(
-        new org.apache.hadoop.mapred.InputSplit[] {split}
+        new org.apache.hadoop.mapred.InputSplit[]{split}
     );
-    EasyMock.expect(split.getLocations()).andReturn(new String[] {"s4", "s2"});
+    EasyMock.expect(split.getLocations()).andReturn(new String[]{"s4", "s2"});
 
     EasyMock.replay(fio, split);
 
     Assert.assertArrayEquals(
-        new String[] {"s1", "s2", "s3", "s4", "s2"},
-        DatasourceInputFormat.getLocations(segments, fio, config).toArray(String[]::new)
+        new String[]{"s1", "s2", "s3", "s4", "s2"},
+        DatasourceInputFormat.getLocations(segments1, fio, config).toArray(String[]::new)
     );
   }
 }
diff --git a/indexing-hadoop/src/test/java/io/druid/indexer/hadoop/DatasourceRecordReaderTest.java b/indexing-hadoop/src/test/java/io/druid/indexer/hadoop/DatasourceRecordReaderTest.java
index 65947dac3d0a..561449171e17 100644
--- a/indexing-hadoop/src/test/java/io/druid/indexer/hadoop/DatasourceRecordReaderTest.java
+++ b/indexing-hadoop/src/test/java/io/druid/indexer/hadoop/DatasourceRecordReaderTest.java
@@ -35,6 +35,7 @@
 import org.junit.Test;
 
 import java.net.URL;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 
@@ -59,21 +60,21 @@ public void testSanity() throws Exception
     InputSplit split = new DatasourceInputSplit(Lists.newArrayList(WindowedDataSegment.of(segment)), null);
 
     Configuration config = new Configuration();
-    config.set(
-        DatasourceInputFormat.CONF_DRUID_SCHEMA,
-        HadoopDruidIndexerConfig.JSON_MAPPER.writeValueAsString(
-            new DatasourceIngestionSpec(
-                segment.getDataSource(),
-                segment.getInterval(),
-                null,
-                null,
-                null,
-                segment.getDimensions(),
-                segment.getMetrics(),
-                false,
-                null
-            )
-        )
+    DatasourceInputFormat.addDataSource(
+        config,
+        new DatasourceIngestionSpec(
+            segment.getDataSource(),
+            segment.getInterval(),
+            null,
+            null,
+            null,
+            segment.getDimensions(),
+            segment.getMetrics(),
+            false,
+            null
+        ),
+        Collections.emptyList(),
+        0
     );
 
     TaskAttemptContext context = EasyMock.createNiceMock(TaskAttemptContext.class);
diff --git a/indexing-hadoop/src/test/java/io/druid/indexer/path/DatasourcePathSpecTest.java b/indexing-hadoop/src/test/java/io/druid/indexer/path/DatasourcePathSpecTest.java
index e98c676761e1..b3770fba92e2 100644
--- a/indexing-hadoop/src/test/java/io/druid/indexer/path/DatasourcePathSpecTest.java
+++ b/indexing-hadoop/src/test/java/io/druid/indexer/path/DatasourcePathSpecTest.java
@@ -19,7 +19,6 @@
 
 package io.druid.indexer.path;
 
-import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
@@ -60,6 +59,7 @@
 import org.junit.Assert;
 import org.junit.Test;
 
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 
@@ -67,12 +67,14 @@
  */
 public class DatasourcePathSpecTest
 {
-  private DatasourceIngestionSpec ingestionSpec;
-  private List<WindowedDataSegment> segments;
+  private DatasourceIngestionSpec ingestionSpec1;
+  private DatasourceIngestionSpec ingestionSpec2;
+  private List<WindowedDataSegment> segments1;
+  private List<WindowedDataSegment> segments2;
 
   public DatasourcePathSpecTest()
   {
-    this.ingestionSpec = new DatasourceIngestionSpec(
+    this.ingestionSpec1 = new DatasourceIngestionSpec(
         "test",
         Intervals.of("2000/3000"),
         null,
@@ -84,10 +86,22 @@ public DatasourcePathSpecTest()
         null
     );
 
-    segments = ImmutableList.of(
+    this.ingestionSpec2 = new DatasourceIngestionSpec(
+        "test2",
+        Intervals.of("2000/3000"),
+        null,
+        null,
+        null,
+        null,
+        null,
+        false,
+        null
+    );
+
+    segments1 = ImmutableList.of(
         WindowedDataSegment.of(
             new DataSegment(
-                ingestionSpec.getDataSource(),
+                ingestionSpec1.getDataSource(),
                 Intervals.of("2000/3000"),
                 "ver",
                 ImmutableMap.<String, Object>of(
@@ -103,7 +117,7 @@ public DatasourcePathSpecTest()
         ),
         WindowedDataSegment.of(
             new DataSegment(
-                ingestionSpec.getDataSource(),
+                ingestionSpec1.getDataSource(),
                 Intervals.of("2050/3000"),
                 "ver",
                 ImmutableMap.<String, Object>of(
@@ -118,6 +132,25 @@ public DatasourcePathSpecTest()
             )
         )
     );
+
+    segments2 = ImmutableList.of(
+        WindowedDataSegment.of(
+            new DataSegment(
+                ingestionSpec2.getDataSource(),
+                Intervals.of("2000/3000"),
+                "ver",
+                ImmutableMap.<String, Object>of(
+                    "type", "local",
+                    "path", "/tmp2/index.zip"
+                ),
+                ImmutableList.of("product2"),
+                ImmutableList.of("visited_sum2", "unique_hosts2"),
+                NoneShardSpec.instance(),
+                9,
+                12334
+            )
+        )
+    );
   }
 
   @Test
@@ -137,7 +170,9 @@ public void configure(Binder binder)
               {
                 binder.bind(UsedSegmentLister.class).toInstance(segmentList);
                 JsonConfigProvider.bindInstance(
-                    binder, Key.get(DruidNode.class, Self.class), new DruidNode("dummy-node", null, null, null, true, false)
+                    binder,
+                    Key.get(DruidNode.class, Self.class),
+                    new DruidNode("dummy-node", null, null, null, true, false)
                 );
               }
             }
@@ -149,7 +184,7 @@ public void configure(Binder binder)
     DatasourcePathSpec expected = new DatasourcePathSpec(
         jsonMapper,
         null,
-        ingestionSpec,
+        ingestionSpec1,
         Long.valueOf(10),
         false
     );
@@ -159,7 +194,7 @@ public void configure(Binder binder)
     expected = new DatasourcePathSpec(
         jsonMapper,
         null,
-        ingestionSpec,
+        ingestionSpec1,
         null,
         false
     );
@@ -168,8 +203,8 @@ public void configure(Binder binder)
 
     expected = new DatasourcePathSpec(
         jsonMapper,
-        segments,
-        ingestionSpec,
+        segments1,
+        ingestionSpec1,
         null,
         false
     );
@@ -178,8 +213,8 @@ public void configure(Binder binder)
 
     expected = new DatasourcePathSpec(
         jsonMapper,
-        segments,
-        ingestionSpec,
+        segments1,
+        ingestionSpec1,
         null,
         true
     );
@@ -194,10 +229,18 @@ public void testAddInputPaths() throws Exception
 
     ObjectMapper mapper = TestHelper.makeJsonMapper();
 
-    DatasourcePathSpec pathSpec = new DatasourcePathSpec(
+    DatasourcePathSpec pathSpec1 = new DatasourcePathSpec(
         mapper,
-        segments,
-        ingestionSpec,
+        segments1,
+        ingestionSpec1,
+        null,
+        false
+    );
+
+    DatasourcePathSpec pathSpec2 = new DatasourcePathSpec(
+        mapper,
+        segments2,
+        ingestionSpec2,
         null,
         false
     );
@@ -207,25 +250,29 @@ public void testAddInputPaths() throws Exception
     EasyMock.expect(job.getConfiguration()).andReturn(config).anyTimes();
     EasyMock.replay(job);
 
-    pathSpec.addInputPaths(hadoopIndexerConfig, job);
-    List<WindowedDataSegment> actualSegments = mapper.readValue(
-        config.get(DatasourceInputFormat.CONF_INPUT_SEGMENTS),
-        new TypeReference<List<WindowedDataSegment>>()
-        {
-        }
+    pathSpec1.addInputPaths(hadoopIndexerConfig, job);
+    pathSpec2.addInputPaths(hadoopIndexerConfig, job);
+
+    Assert.assertEquals(
+        ImmutableList.of(ingestionSpec1.getDataSource(), ingestionSpec2.getDataSource()),
+        DatasourceInputFormat.getDataSources(config)
     );
 
-    Assert.assertEquals(segments, actualSegments);
+    Assert.assertEquals(segments1, DatasourceInputFormat.getSegments(config, ingestionSpec1.getDataSource()));
+    Assert.assertEquals(segments2, DatasourceInputFormat.getSegments(config, ingestionSpec2.getDataSource()));
 
-    DatasourceIngestionSpec actualIngestionSpec = mapper.readValue(
-        config.get(DatasourceInputFormat.CONF_DRUID_SCHEMA),
-        DatasourceIngestionSpec.class
-    );
     Assert.assertEquals(
-        ingestionSpec
+        ingestionSpec1
             .withDimensions(ImmutableList.of("product"))
             .withMetrics(ImmutableList.of("visited_sum")),
-        actualIngestionSpec
+        DatasourceInputFormat.getIngestionSpec(config, ingestionSpec1.getDataSource())
+    );
+
+    Assert.assertEquals(
+        ingestionSpec2
+            .withDimensions(ImmutableList.of("product2"))
+            .withMetrics(ImmutableList.of("visited_sum")),
+        DatasourceInputFormat.getIngestionSpec(config, ingestionSpec2.getDataSource())
     );
   }
 
@@ -239,7 +286,7 @@ public void testAddInputPathsWithNoSegments() throws Exception
     DatasourcePathSpec pathSpec = new DatasourcePathSpec(
         mapper,
         null,
-        ingestionSpec,
+        ingestionSpec1,
         null,
         false
     );
@@ -261,22 +308,22 @@ public void testAddInputPathsWithNoSegments() throws Exception
     pathSpec = new DatasourcePathSpec(
         mapper,
         null,
-        ingestionSpec.withIgnoreWhenNoSegments(true),
+        ingestionSpec1.withIgnoreWhenNoSegments(true),
         null,
         false
     );
     pathSpec.addInputPaths(hadoopIndexerConfig, job);
 
-    Assert.assertNull(config.get(DatasourceInputFormat.CONF_INPUT_SEGMENTS));
-    Assert.assertNull(config.get(DatasourceInputFormat.CONF_DRUID_SCHEMA));
+    Assert.assertEquals(Collections.emptyList(), DatasourceInputFormat.getDataSources(config));
   }
 
+  @SuppressWarnings("unchecked")
   private HadoopDruidIndexerConfig makeHadoopDruidIndexerConfig()
   {
     return new HadoopDruidIndexerConfig(
         new HadoopIngestionSpec(
             new DataSchema(
-                ingestionSpec.getDataSource(),
+                ingestionSpec1.getDataSource(),
                 HadoopDruidIndexerConfig.JSON_MAPPER.convertValue(
                     new StringInputRowParser(
                         new CSVParseSpec(