diff --git a/integration-tests/src/main/java/io/druid/testing/utils/TestQueryHelper.java b/integration-tests/src/main/java/io/druid/testing/utils/TestQueryHelper.java
index f0369d31bc5..bb00c7dcf70 100644
--- a/integration-tests/src/main/java/io/druid/testing/utils/TestQueryHelper.java
+++ b/integration-tests/src/main/java/io/druid/testing/utils/TestQueryHelper.java
@@ -21,10 +21,15 @@ package io.druid.testing.utils;
 
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.google.common.collect.ImmutableList;
 import com.google.inject.Inject;
-
 import io.druid.java.util.common.ISE;
+import io.druid.java.util.common.granularity.Granularities;
 import io.druid.java.util.common.logger.Logger;
+import io.druid.query.Druids;
+import io.druid.query.aggregation.AggregatorFactory;
+import io.druid.query.aggregation.LongSumAggregatorFactory;
+import io.druid.query.timeseries.TimeseriesQuery;
 import io.druid.testing.IntegrationTestingConfig;
 import io.druid.testing.clients.QueryResourceTestClient;
 
@@ -118,4 +123,27 @@ public class TestQueryHelper
   {
     return String.format("%s/druid/v2?pretty", broker);
   }
+
+  @SuppressWarnings("unchecked")
+  public int countRows(String dataSource, String interval)
+  {
+    TimeseriesQuery query = Druids.newTimeseriesQueryBuilder()
+                                  .dataSource(dataSource)
+                                  .aggregators(
+                                      ImmutableList.<AggregatorFactory>of(
+                                          new LongSumAggregatorFactory("rows", "count")
+                                      )
+                                  ).granularity(Granularities.ALL)
+                                  .intervals(interval)
+                                  .build();
+
+    List<Map<String, Object>> results = queryClient.query(getBrokerURL(), query);
+    if (results.isEmpty()) {
+      return 0;
+    } else {
+      Map<String, Object> map = (Map<String, Object>) results.get(0).get("result");
+
+      return (Integer) map.get("rows");
+    }
+  }
 }
diff --git a/integration-tests/src/test/java/io/druid/tests/indexer/ITIndexerTest.java b/integration-tests/src/test/java/io/druid/tests/indexer/ITIndexerTest.java
index ef5328fc3db..defa334251c 100644
--- a/integration-tests/src/test/java/io/druid/tests/indexer/ITIndexerTest.java
+++ b/integration-tests/src/test/java/io/druid/tests/indexer/ITIndexerTest.java
@@ -21,7 +21,6 @@ package io.druid.tests.indexer;
 
 import com.google.common.base.Throwables;
 import com.google.inject.Inject;
-
 import io.druid.java.util.common.logger.Logger;
 import io.druid.testing.IntegrationTestingConfig;
 import io.druid.testing.clients.ClientInfoResourceTestClient;
@@ -66,7 +65,7 @@ public class ITIndexerTest extends AbstractIndexerTest
       Assert.assertFalse("dimensions : " + dimensions, dimensions.contains("robot"));
     }
     catch (Exception e) {
-      e.printStackTrace();
+      LOG.error(e, "Error while testing");
       throw Throwables.propagate(e);
     }
     finally {
diff --git a/integration-tests/src/test/java/io/druid/tests/indexer/ITUnionQueryTest.java b/integration-tests/src/test/java/io/druid/tests/indexer/ITUnionQueryTest.java
index e3ca8726df6..dbdc49f0107 100644
--- a/integration-tests/src/test/java/io/druid/tests/indexer/ITUnionQueryTest.java
+++ b/integration-tests/src/test/java/io/druid/tests/indexer/ITUnionQueryTest.java
@@ -86,8 +86,21 @@ public class ITUnionQueryTest extends AbstractIndexerTest
         postEvents(i);
       }
 
-      // sleep for a while to let the events ingested
-      TimeUnit.SECONDS.sleep(5);
+      // wait until all events are ingested
+      RetryUtil.retryUntil(
+          () -> {
+            for (int i = 0; i < numTasks; i++) {
+              if (queryHelper.countRows(UNION_DATASOURCE + i, "2013-08-31/2013-09-01") < 5) {
+                return false;
+              }
+            }
+            return true;
+          },
+          true,
+          1000,
+          100,
+          "Waiting all events are ingested"
+      );
 
       // should hit the queries on realtime task
       LOG.info("Running Union Queries..");
@@ -110,7 +123,7 @@ public class ITUnionQueryTest extends AbstractIndexerTest
               }
             },
             true,
-            60000,
+            10000,
             10,
             "Real-time generated segments loaded"
         );
@@ -120,7 +133,7 @@ public class ITUnionQueryTest extends AbstractIndexerTest
 
     }
     catch (Exception e) {
-      e.printStackTrace();
+      LOG.error(e, "Error while testing");
       throw Throwables.propagate(e);
     }
     finally {