From c0129ebcc2a2f2c7c70e295205a5f5be9eb0795e Mon Sep 17 00:00:00 2001
From: Igor Motov <igor@motovs.org>
Date: Fri, 3 Oct 2014 13:23:11 -0400
Subject: [PATCH] Snapshot/Restore: make it possible to delete snapshots with
 missing metadata file

Fixes #7980
---
 .../blobstore/BlobStoreRepository.java        | 23 +++++++++---
 .../SharedClusterSnapshotRestoreTests.java    | 35 +++++++++++++++++++
 2 files changed, 53 insertions(+), 5 deletions(-)

diff --git a/src/main/java/org/elasticsearch/repositories/blobstore/BlobStoreRepository.java b/src/main/java/org/elasticsearch/repositories/blobstore/BlobStoreRepository.java
index 65fc3ad1a7468..3233b38d7520b 100644
--- a/src/main/java/org/elasticsearch/repositories/blobstore/BlobStoreRepository.java
+++ b/src/main/java/org/elasticsearch/repositories/blobstore/BlobStoreRepository.java
@@ -44,6 +44,7 @@
 import org.elasticsearch.common.unit.ByteSizeUnit;
 import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.common.xcontent.*;
+import org.elasticsearch.index.shard.IndexShardException;
 import org.elasticsearch.index.shard.ShardId;
 import org.elasticsearch.index.snapshots.IndexShardRepository;
 import org.elasticsearch.index.snapshots.blobstore.BlobStoreIndexShardRepository;
@@ -262,7 +263,12 @@ public void initializeSnapshot(SnapshotId snapshotId, ImmutableList<String> indi
     @Override
     public void deleteSnapshot(SnapshotId snapshotId) {
         Snapshot snapshot = readSnapshot(snapshotId);
-        MetaData metaData = readSnapshotMetaData(snapshotId, snapshot.indices(), true);
+        MetaData metaData = null;
+        try {
+            metaData = readSnapshotMetaData(snapshotId, snapshot.indices(), true);
+        } catch (SnapshotException ex) {
+            logger.warn("cannot read metadata for snapshot [{}]", ex, snapshotId);
+        }
         try {
             String blobName = snapshotBlobName(snapshotId);
             // Delete snapshot file first so we wouldn't end up with partially deleted snapshot that looks OK
@@ -289,10 +295,17 @@ public void deleteSnapshot(SnapshotId snapshotId) {
                 } catch (IOException ex) {
                     logger.warn("[{}] failed to delete metadata for index [{}]", ex, snapshotId, index);
                 }
-                IndexMetaData indexMetaData = metaData.index(index);
-                if (indexMetaData != null) {
-                    for (int i = 0; i < indexMetaData.getNumberOfShards(); i++) {
-                        indexShardRepository.delete(snapshotId, new ShardId(index, i));
+                if (metaData != null) {
+                    IndexMetaData indexMetaData = metaData.index(index);
+                    if (indexMetaData != null) {
+                        for (int i = 0; i < indexMetaData.getNumberOfShards(); i++) {
+                            ShardId shardId = new ShardId(index, i);
+                            try {
+                                indexShardRepository.delete(snapshotId, shardId);
+                            } catch (IndexShardException | SnapshotException ex) {
+                                logger.warn("[{}] failed to delete shard data for shard [{}]", ex, snapshotId, shardId);
+                            }
+                        }
                     }
                 }
             }
diff --git a/src/test/java/org/elasticsearch/snapshots/SharedClusterSnapshotRestoreTests.java b/src/test/java/org/elasticsearch/snapshots/SharedClusterSnapshotRestoreTests.java
index 3fd25637902e0..48dbfb5d01e19 100644
--- a/src/test/java/org/elasticsearch/snapshots/SharedClusterSnapshotRestoreTests.java
+++ b/src/test/java/org/elasticsearch/snapshots/SharedClusterSnapshotRestoreTests.java
@@ -740,6 +740,41 @@ public void deleteSnapshotWithMissingIndexAndShardMetadataTest() throws Exceptio
         assertThrows(client.admin().cluster().prepareGetSnapshots("test-repo").addSnapshots("test-snap-1"), SnapshotMissingException.class);
     }
 
+    @Test
+    public void deleteSnapshotWithMissingMetadataTest() throws Exception {
+        Client client = client();
+
+        File repo = newTempDir(LifecycleScope.SUITE);
+        logger.info("-->  creating repository at " + repo.getAbsolutePath());
+        assertAcked(client.admin().cluster().preparePutRepository("test-repo")
+                .setType("fs").setSettings(ImmutableSettings.settingsBuilder()
+                        .put("location", repo)
+                        .put("compress", false)
+                        .put("chunk_size", randomIntBetween(100, 1000))));
+
+        createIndex("test-idx-1", "test-idx-2");
+        ensureYellow();
+        logger.info("--> indexing some data");
+        indexRandom(true,
+                client().prepareIndex("test-idx-1", "doc").setSource("foo", "bar"),
+                client().prepareIndex("test-idx-2", "doc").setSource("foo", "bar"));
+
+        logger.info("--> creating snapshot");
+        CreateSnapshotResponse createSnapshotResponse = client.admin().cluster().prepareCreateSnapshot("test-repo", "test-snap-1").setWaitForCompletion(true).setIndices("test-idx-*").get();
+        assertThat(createSnapshotResponse.getSnapshotInfo().successfulShards(), greaterThan(0));
+        assertThat(createSnapshotResponse.getSnapshotInfo().successfulShards(), equalTo(createSnapshotResponse.getSnapshotInfo().totalShards()));
+
+        logger.info("--> delete index metadata and shard metadata");
+        File metadata = new File(repo, "metadata-test-snap-1");
+        assertThat(metadata.delete(), equalTo(true));
+
+        logger.info("--> delete snapshot");
+        client.admin().cluster().prepareDeleteSnapshot("test-repo", "test-snap-1").get();
+
+        logger.info("--> make sure snapshot doesn't exist");
+        assertThrows(client.admin().cluster().prepareGetSnapshots("test-repo").addSnapshots("test-snap-1"), SnapshotMissingException.class);
+    }
+
     @Test
     @TestLogging("snapshots:TRACE")
     public void snapshotClosedIndexTest() throws Exception {