From 315ccb76b819790a4861bf16e493dba47605291b Mon Sep 17 00:00:00 2001
From: anantmf <anantmf@outlook.com>
Date: Tue, 5 Feb 2019 15:45:45 -0800
Subject: [PATCH] Fix for getSingleObjectSummary, replacing keyCount with
 objectSummaries().size (#7000)

* Instead of using keyCount, changing it to check the size of objectSummaries.

For issue:
https://github.com/apache/incubator-druid/issues/6980
https://github.com/apache/incubator-druid/issues/6980#issuecomment-460006580

* Changing another usage of keyCount with size of objectSummaries.

* Adding some comments to explain why using keyCount is not working as expected.
---
 .../java/org/apache/druid/storage/s3/S3DataSegmentMover.java | 5 ++++-
 .../src/main/java/org/apache/druid/storage/s3/S3Utils.java   | 5 ++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/extensions-core/s3-extensions/src/main/java/org/apache/druid/storage/s3/S3DataSegmentMover.java b/extensions-core/s3-extensions/src/main/java/org/apache/druid/storage/s3/S3DataSegmentMover.java
index 4fd54b49956..84a76d15e41 100644
--- a/extensions-core/s3-extensions/src/main/java/org/apache/druid/storage/s3/S3DataSegmentMover.java
+++ b/extensions-core/s3-extensions/src/main/java/org/apache/druid/storage/s3/S3DataSegmentMover.java
@@ -174,7 +174,10 @@ public class S3DataSegmentMover implements DataSegmentMover
               .withPrefix(s3Path)
               .withMaxKeys(1)
       );
-      if (listResult.getKeyCount() == 0) {
+      // Using getObjectSummaries().size() instead of getKeyCount as, in some cases
+      // it is observed that even though the getObjectSummaries returns some data
+      // keyCount is still zero.
+      if (listResult.getObjectSummaries().size() == 0) {
         // should never happen
         throw new ISE("Unable to list object [s3://%s/%s]", s3Bucket, s3Path);
       }
diff --git a/extensions-core/s3-extensions/src/main/java/org/apache/druid/storage/s3/S3Utils.java b/extensions-core/s3-extensions/src/main/java/org/apache/druid/storage/s3/S3Utils.java
index e0a3dac8cae..97858864b14 100644
--- a/extensions-core/s3-extensions/src/main/java/org/apache/druid/storage/s3/S3Utils.java
+++ b/extensions-core/s3-extensions/src/main/java/org/apache/druid/storage/s3/S3Utils.java
@@ -251,7 +251,10 @@ public class S3Utils
         .withMaxKeys(1);
     final ListObjectsV2Result result = s3Client.listObjectsV2(request);
 
-    if (result.getKeyCount() == 0) {
+    // Using getObjectSummaries().size() instead of getKeyCount as, in some cases
+    // it is observed that even though the getObjectSummaries returns some data
+    // keyCount is still zero.
+    if (result.getObjectSummaries().size() == 0) {
       throw new ISE("Cannot find object for bucket[%s] and key[%s]", bucket, key);
     }
     final S3ObjectSummary objectSummary = result.getObjectSummaries().get(0);