add a unique string to intermediate path for the hadoop indexing task

indexing-hadoop/src/main/java/io/druid/indexer/HadoopDruidIndexerConfig.java

@@ -476,10 +476,11 @@ public class HadoopDruidIndexerConfig
   {
     return new Path(
         String.format(
-            "%s/%s/%s",
+            "%s/%s/%s/%s",
             getWorkingPath(),
             schema.getDataSchema().getDataSource(),
-            schema.getTuningConfig().getVersion().replace(":", "")
+            schema.getTuningConfig().getVersion().replace(":", ""),
+            schema.getUniqueId()
         )
     );
   }

indexing-hadoop/src/main/java/io/druid/indexer/HadoopIngestionSpec.java

@@ -22,6 +22,7 @@ import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Ordering;
+import io.druid.common.utils.UUIDUtils;
 import io.druid.indexer.hadoop.DatasourceIngestionSpec;
 import io.druid.indexer.hadoop.WindowedDataSegment;
 import io.druid.indexer.path.UsedSegmentLister;
@@ -45,11 +46,15 @@ public class HadoopIngestionSpec extends IngestionSpec<HadoopIOConfig, HadoopTun
   private final HadoopIOConfig ioConfig;
   private final HadoopTuningConfig tuningConfig;
 
+  //this is used in the temporary paths on the hdfs unique to an hadoop indexing task
+  private final String uniqueId;
+
   @JsonCreator
   public HadoopIngestionSpec(
       @JsonProperty("dataSchema") DataSchema dataSchema,
       @JsonProperty("ioConfig") HadoopIOConfig ioConfig,
-      @JsonProperty("tuningConfig") HadoopTuningConfig tuningConfig
+      @JsonProperty("tuningConfig") HadoopTuningConfig tuningConfig,
+      @JsonProperty("uniqueId") String uniqueId
   )
   {
     super(dataSchema, ioConfig, tuningConfig);
@@ -57,6 +62,17 @@ public class HadoopIngestionSpec extends IngestionSpec<HadoopIOConfig, HadoopTun
     this.dataSchema = dataSchema;
     this.ioConfig = ioConfig;
     this.tuningConfig = tuningConfig == null ? HadoopTuningConfig.makeDefaultTuningConfig() : tuningConfig;
+    this.uniqueId = uniqueId == null ? UUIDUtils.generateUuid() : uniqueId;
+  }
+
+  //for unit tests
+  public HadoopIngestionSpec(
+      DataSchema dataSchema,
+      HadoopIOConfig ioConfig,
+      HadoopTuningConfig tuningConfig
+  )
+  {
+    this(dataSchema, ioConfig, tuningConfig, null);
   }
 
   @JsonProperty("dataSchema")
@@ -80,12 +96,19 @@ public class HadoopIngestionSpec extends IngestionSpec<HadoopIOConfig, HadoopTun
     return tuningConfig;
   }
 
+  @JsonProperty("uniqueId")
+  public String getUniqueId()
+  {
+    return uniqueId;
+  }
+
   public HadoopIngestionSpec withDataSchema(DataSchema schema)
   {
     return new HadoopIngestionSpec(
         schema,
         ioConfig,
-        tuningConfig
+        tuningConfig,
+        uniqueId
     );
   }
 
@@ -94,7 +117,8 @@ public class HadoopIngestionSpec extends IngestionSpec<HadoopIOConfig, HadoopTun
     return new HadoopIngestionSpec(
         dataSchema,
         config,
-        tuningConfig
+        tuningConfig,
+        uniqueId
     );
   }
 
@@ -103,7 +127,8 @@ public class HadoopIngestionSpec extends IngestionSpec<HadoopIOConfig, HadoopTun
     return new HadoopIngestionSpec(
         dataSchema,
         ioConfig,
-        config
+        config,
+        uniqueId
     );
   }
 

indexing-hadoop/src/test/java/io/druid/indexer/HadoopIngestionSpecTest.java

@@ -19,6 +19,7 @@ package io.druid.indexer;
 
 import com.fasterxml.jackson.databind.InjectableValues;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.google.common.base.Strings;
 import com.google.common.base.Throwables;
 import com.google.common.collect.Lists;
 import io.druid.indexer.partitions.HashedPartitionsSpec;
@@ -238,6 +239,32 @@ public class HadoopIngestionSpecTest
         schema.getTuningConfig().getPartitionsSpec().isDeterminingPartitions(),
         false
     );
+
+    Assert.assertFalse(Strings.isNullOrEmpty(schema.getUniqueId()));
+  }
+
+  @Test
+  public void testUniqueId() throws Exception
+  {
+    final HadoopIngestionSpec schema = jsonReadWriteRead(
+        "{\"uniqueId\" : \"test_unique_id\"}",
+        HadoopIngestionSpec.class
+    );
+
+    Assert.assertEquals("test_unique_id", schema.getUniqueId());
+
+    //test uniqueId assigned is really unique
+    final String id1 = jsonReadWriteRead(
+        "{}",
+        HadoopIngestionSpec.class
+    ).getUniqueId();
+
+    final String id2 = jsonReadWriteRead(
+        "{}",
+        HadoopIngestionSpec.class
+    ).getUniqueId();
+
+    Assert.assertNotEquals(id1, id2);
   }
 
   @Test