drop index.shard.check_on_startup: fix

Relates #31389

Author: Vladimir Dolzhenko

docs/reference/index-modules.asciidoc

@@ -63,12 +63,6 @@ corruption is detected, it will prevent the shard from being opened. Accepts:
     Check for both physical and logical corruption. This is much more
     expensive in terms of CPU and memory usage.
 
-`fix`::
-
-    Check for both physical and logical corruption.  Segments that were reported
-    as corrupted will be automatically removed. This option *may result in data loss*.
-    Use with extreme caution!
-
 WARNING: Expert only. Checking shards may take a lot of time on large indices.
 --
 

server/src/main/java/org/elasticsearch/index/IndexSettings.java

@@ -74,11 +74,10 @@ public final class IndexSettings {
         switch(s) {
             case "false":
             case "true":
-            case "fix":
             case "checksum":
                 return s;
             default:
-                throw new IllegalArgumentException("unknown value for [index.shard.check_on_startup] must be one of [true, false, fix, checksum] but was: " + s);
+                throw new IllegalArgumentException("unknown value for [index.shard.check_on_startup] must be one of [true, false, checksum] but was: " + s);
         }
     }, Property.IndexScope);
 

server/src/main/java/org/elasticsearch/index/shard/IndexShard.java

@@ -1298,7 +1298,7 @@ private void innerOpenEngineAndTranslog() throws IOException {
         }
         recoveryState.setStage(RecoveryState.Stage.VERIFY_INDEX);
         // also check here, before we apply the translog
-        if (Booleans.isTrue(checkIndexOnStartup)) {
+        if (Booleans.isTrue(checkIndexOnStartup) || "checksum".equals(checkIndexOnStartup)) {
             try {
                 checkIndex();
             } catch (IOException ex) {
@@ -1890,6 +1890,9 @@ void checkIndex() throws IOException {
         if (store.tryIncRef()) {
             try {
                 doCheckIndex();
+            } catch (IOException e) {
+                store.markStoreCorrupted(e);
+                throw e;
             } finally {
                 store.decRef();
             }
@@ -1933,18 +1936,7 @@ private void doCheckIndex() throws IOException {
                     return;
                 }
                 logger.warn("check index [failure]\n{}", os.bytes().utf8ToString());
-                if ("fix".equals(checkIndexOnStartup)) {
-                    if (logger.isDebugEnabled()) {
-                        logger.debug("fixing index, writing new segments file ...");
-                    }
-                    store.exorciseIndex(status);
-                    if (logger.isDebugEnabled()) {
-                        logger.debug("index fixed, wrote new segments file \"{}\"", status.segmentsFileName);
-                    }
-                } else {
-                    // only throw a failure if we are not going to fix the index
-                    throw new IllegalStateException("index check failure but can't fix it");
-                }
+                throw new IllegalStateException("index check failure");
             }
         }
 

server/src/main/java/org/elasticsearch/index/store/Store.java

@@ -134,7 +134,8 @@ public class Store extends AbstractIndexShardComponent implements Closeable, Ref
     static final int VERSION_STACK_TRACE = 1; // we write the stack trace too since 1.4.0
     static final int VERSION_START = 0;
     static final int VERSION = VERSION_WRITE_THROWABLE;
-    static final String CORRUPTED = "corrupted_";
+    // public is for test purposes
+    public static final String CORRUPTED = "corrupted_";
     public static final Setting<TimeValue> INDEX_STORE_STATS_REFRESH_INTERVAL_SETTING =
         Setting.timeSetting("index.store.stats_refresh_interval", TimeValue.timeValueSeconds(10), Property.IndexScope);
 
@@ -360,18 +361,6 @@ public CheckIndex.Status checkIndex(PrintStream out) throws IOException {
         }
     }
 
-    /**
-     * Repairs the index using the previous returned status from {@link #checkIndex(PrintStream)}.
-     */
-    public void exorciseIndex(CheckIndex.Status status) throws IOException {
-        metadataLock.writeLock().lock();
-        try (CheckIndex checkIndex = new CheckIndex(directory)) {
-            checkIndex.exorciseIndex(status);
-        } finally {
-            metadataLock.writeLock().unlock();
-        }
-    }
-
     public StoreStats stats() throws IOException {
         ensureOpen();
         return new StoreStats(directory.estimateSize());

server/src/test/java/org/elasticsearch/action/admin/indices/template/put/MetaDataIndexTemplateServiceTests.java

@@ -69,7 +69,7 @@ public void testIndexTemplateInvalidNumberOfShards() {
                 containsString("Failed to parse value [0] for setting [index.number_of_shards] must be >= 1"));
         assertThat(throwables.get(0).getMessage(),
                 containsString("unknown value for [index.shard.check_on_startup] " +
-                                "must be one of [true, false, fix, checksum] but was: blargh"));
+                                "must be one of [true, false, checksum] but was: blargh"));
     }
 
     public void testIndexTemplateValidationAccumulatesValidationErrors() {

server/src/test/java/org/elasticsearch/index/shard/IndexShardTests.java

@@ -22,11 +22,13 @@
 import org.apache.lucene.index.CorruptIndexException;
 import org.apache.lucene.index.DirectoryReader;
 import org.apache.lucene.index.IndexCommit;
+import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.index.Term;
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.search.TermQuery;
 import org.apache.lucene.search.TopDocs;
 import org.apache.lucene.store.AlreadyClosedException;
+import org.apache.lucene.store.BaseDirectoryWrapper;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.FilterDirectory;
 import org.apache.lucene.store.IOContext;
@@ -53,6 +55,7 @@
 import org.elasticsearch.cluster.routing.ShardRoutingState;
 import org.elasticsearch.cluster.routing.TestShardRouting;
 import org.elasticsearch.cluster.routing.UnassignedInfo;
+import org.elasticsearch.common.CheckedFunction;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.UUIDs;
 import org.elasticsearch.common.breaker.CircuitBreaker;
@@ -93,6 +96,7 @@
 import org.elasticsearch.index.seqno.SeqNoStats;
 import org.elasticsearch.index.seqno.SequenceNumbers;
 import org.elasticsearch.index.snapshots.IndexShardSnapshotStatus;
+import org.elasticsearch.index.store.DirectoryService;
 import org.elasticsearch.index.store.Store;
 import org.elasticsearch.index.store.StoreStats;
 import org.elasticsearch.index.translog.TestTranslog;
@@ -110,6 +114,7 @@
 import org.elasticsearch.snapshots.SnapshotId;
 import org.elasticsearch.snapshots.SnapshotInfo;
 import org.elasticsearch.snapshots.SnapshotShardFailure;
+import org.elasticsearch.test.CorruptionUtils;
 import org.elasticsearch.test.DummyShardLock;
 import org.elasticsearch.test.FieldMaskingReader;
 import org.elasticsearch.test.VersionUtils;
@@ -118,7 +123,11 @@
 
 import java.io.IOException;
 import java.nio.charset.Charset;
+import java.nio.file.FileVisitResult;
+import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.SimpleFileVisitor;
+import java.nio.file.attribute.BasicFileAttributes;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -1216,7 +1225,7 @@ public String[] listAll() throws IOException {
         };
 
         try (Store store = createStore(shardId, new IndexSettings(metaData, Settings.EMPTY), directory)) {
-            IndexShard shard = newShard(shardRouting, shardPath, metaData, store,
+            IndexShard shard = newShard(shardRouting, shardPath, metaData, i -> store,
                     null, new InternalEngineFactory(), () -> {
                     }, EMPTY_EVENT_LISTENER);
             AtomicBoolean failureCallbackTriggered = new AtomicBoolean(false);
@@ -2561,6 +2570,104 @@ public void testReadSnapshotConcurrently() throws IOException, InterruptedExcept
         closeShards(newShard);
     }
 
+    public void testIndexCheckChecksum() throws Exception {
+        final boolean primary = true;
+
+        IndexShard indexShard = newStartedShard(primary);
+
+        final long numDocs = between(10, 100);
+        for (long i = 0; i < numDocs; i++) {
+            indexDoc(indexShard, "_doc", Long.toString(i), "{}");
+        }
+        indexShard.flush(new FlushRequest());
+        closeShards(indexShard);
+
+        // start shard with checksum - it has to pass successfully
+
+        final ShardRouting shardRouting = ShardRoutingHelper.initWithSameId(indexShard.routingEntry(),
+            primary ? RecoverySource.StoreRecoverySource.EXISTING_STORE_INSTANCE : RecoverySource.PeerRecoverySource.INSTANCE
+        );
+        final IndexMetaData indexMetaData = IndexMetaData.builder(indexShard.indexSettings().getIndexMetaData())
+            .settings(Settings.builder()
+                .put(indexShard.indexSettings.getSettings())
+                .put(IndexSettings.INDEX_CHECK_ON_STARTUP.getKey(), "checksum"))
+            .build();
+
+        final ShardPath shardPath = indexShard.shardPath();
+
+        final IndexShard newShard = newShard(shardRouting, shardPath, indexMetaData,
+            null, null, indexShard.engineFactory,
+            indexShard.getGlobalCheckpointSyncer(), EMPTY_EVENT_LISTENER);
+
+        closeShards(newStartedShard(p -> newShard, primary));
+
+        // corrupt files
+        final Path indexPath = shardPath.getDataPath().resolve("index");
+        final Path[] filesToCorrupt =
+            Files.walk(indexPath)
+                .filter(p -> Files.isRegularFile(p) && IndexWriter.WRITE_LOCK_NAME.equals(p.getFileName().toString()) == false)
+                .toArray(Path[]::new);
+        CorruptionUtils.corruptFile(random(), filesToCorrupt);
+
+        // check that corrupt marker is *NOT* there
+        final AtomicInteger corruptedMarkerCount = new AtomicInteger();
+        final SimpleFileVisitor<Path> corruptedVisitor = new SimpleFileVisitor<Path>() {
+            @Override
+            public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
+                if (Files.isRegularFile(file) && file.getFileName().toString().startsWith(Store.CORRUPTED)) {
+                    corruptedMarkerCount.incrementAndGet();
+                }
+                return FileVisitResult.CONTINUE;
+            }
+        };
+        Files.walkFileTree(indexPath, corruptedVisitor);
+
+        assertThat("store is clean",
+            corruptedMarkerCount.get(), equalTo(0));
+
+        // storeProvider that does not perform check index on close - it is corrupted
+        final CheckedFunction<IndexSettings, Store, IOException> storeProvider = indexSettings -> {
+            final ShardId shardId = shardPath.getShardId();
+            final DirectoryService directoryService = new DirectoryService(shardId, indexSettings) {
+                @Override
+                public Directory newDirectory() throws IOException {
+                    final BaseDirectoryWrapper baseDirectoryWrapper = newFSDirectory(shardPath.resolveIndex());
+                    // index is corrupted - don't even try to check index on close - it fails
+                    baseDirectoryWrapper.setCheckIndexOnClose(false);
+                    return baseDirectoryWrapper;
+                }
+            };
+            return new Store(shardId, indexSettings, directoryService, new DummyShardLock(shardId));
+        };
+
+        // try to start shard on corrupted files
+        final IndexShard corruptedShard = newShard(shardRouting, shardPath, indexMetaData,
+            storeProvider, null, indexShard.engineFactory,
+            indexShard.getGlobalCheckpointSyncer(), EMPTY_EVENT_LISTENER);
+
+        expectThrows(IndexShardRecoveryException.class, () -> newStartedShard(p -> corruptedShard, primary));
+        closeShards(corruptedShard);
+
+        // check that corrupt marker is there
+        Files.walkFileTree(indexPath, corruptedVisitor);
+        assertThat("store has to be marked as corrupted",
+            corruptedMarkerCount.get(), equalTo(1));
+
+        // try to start another time shard on corrupted files
+        final IndexShard corruptedShard2 = newShard(shardRouting, shardPath, indexMetaData,
+            storeProvider, null, indexShard.engineFactory,
+            indexShard.getGlobalCheckpointSyncer(), EMPTY_EVENT_LISTENER);
+
+        expectThrows(IndexShardRecoveryException.class, () -> newStartedShard(p -> corruptedShard2, primary));
+        closeShards(corruptedShard2);
+
+        // check that corrupt marker is there
+        corruptedMarkerCount.set(0);
+        Files.walkFileTree(indexPath, corruptedVisitor);
+        assertThat("store still has a single corrupt marker",
+            corruptedMarkerCount.get(), equalTo(1));
+    }
+
     /**
      * Simulates a scenario that happens when we are async fetching snapshot metadata from GatewayService
      * and checking index concurrently. This should always be possible without any exception.
@@ -2584,7 +2691,7 @@ public void testReadSnapshotAndCheckIndexConcurrently() throws Exception {
         final IndexMetaData indexMetaData = IndexMetaData.builder(indexShard.indexSettings().getIndexMetaData())
             .settings(Settings.builder()
                 .put(indexShard.indexSettings.getSettings())
-                .put(IndexSettings.INDEX_CHECK_ON_STARTUP.getKey(), randomFrom("false", "true", "checksum", "fix")))
+                .put(IndexSettings.INDEX_CHECK_ON_STARTUP.getKey(), randomFrom("false", "true", "checksum")))
             .build();
         final IndexShard newShard = newShard(shardRouting, indexShard.shardPath(), indexMetaData,
                 null, null, indexShard.engineFactory, indexShard.getGlobalCheckpointSyncer(), EMPTY_EVENT_LISTENER);