HDDS-4488. Open RocksDB read only when loading containers at Datanode startup

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/common/utils/ContainerCache.java

@@ -157,7 +157,7 @@ public ReferenceCountedDB getDB(long containerID, String containerDBType,
       try {
         long start = Time.monotonicNow();
         DatanodeStore store = BlockUtils.getUncachedDatanodeStore(containerID,
-            containerDBPath, schemaVersion, conf);
+            containerDBPath, schemaVersion, conf, false);
         db = new ReferenceCountedDB(store, containerDBPath);
         metrics.incDbOpenLatency(Time.monotonicNow() - start);
       } catch (Exception e) {

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/keyvalue/helpers/BlockUtils.java

@@ -61,15 +61,15 @@ private BlockUtils() {
    */
   public static DatanodeStore getUncachedDatanodeStore(long containerID,
       String containerDBPath, String schemaVersion,
-      ConfigurationSource conf) throws IOException {
+      ConfigurationSource conf, boolean readOnly) throws IOException {
 
     DatanodeStore store;
     if (schemaVersion.equals(OzoneConsts.SCHEMA_V1)) {
       store = new DatanodeStoreSchemaOneImpl(conf,
-          containerID, containerDBPath);
+          containerID, containerDBPath, readOnly);
     } else if (schemaVersion.equals(OzoneConsts.SCHEMA_V2)) {
       store = new DatanodeStoreSchemaTwoImpl(conf,
-          containerID, containerDBPath);
+          containerID, containerDBPath, readOnly);
     } else {
       throw new IllegalArgumentException(
           "Unrecognized database schema version: " + schemaVersion);
@@ -88,11 +88,11 @@ public static DatanodeStore getUncachedDatanodeStore(long containerID,
    * @throws IOException
    */
   public static DatanodeStore getUncachedDatanodeStore(
-      KeyValueContainerData containerData, ConfigurationSource conf)
-      throws IOException {
+      KeyValueContainerData containerData, ConfigurationSource conf,
+      boolean readOnly) throws IOException {
     return getUncachedDatanodeStore(containerData.getContainerID(),
         containerData.getDbFile().getAbsolutePath(),
-        containerData.getSchemaVersion(), conf);
+        containerData.getSchemaVersion(), conf, readOnly);
   }
 
   /**

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/keyvalue/helpers/KeyValueContainerUtil.java

@@ -106,10 +106,10 @@ public static void createContainerMetaData(long containerID,
     DatanodeStore store;
     if (schemaVersion.equals(OzoneConsts.SCHEMA_V1)) {
       store = new DatanodeStoreSchemaOneImpl(conf,
-              containerID, dbFile.getAbsolutePath());
+              containerID, dbFile.getAbsolutePath(), false);
     } else if (schemaVersion.equals(OzoneConsts.SCHEMA_V2)) {
       store = new DatanodeStoreSchemaTwoImpl(conf,
-              containerID, dbFile.getAbsolutePath());
+              containerID, dbFile.getAbsolutePath(), false);
     } else {
       throw new IllegalArgumentException(
               "Unrecognized schema version for container: " + schemaVersion);
@@ -192,7 +192,8 @@ public static void parseKVContainerData(KeyValueContainerData kvContainerData,
     DatanodeStore store = null;
     try {
       try {
-        store = BlockUtils.getUncachedDatanodeStore(kvContainerData, config);
+        store = BlockUtils.getUncachedDatanodeStore(
+            kvContainerData, config, true);
       } catch (IOException e) {
         // If an exception is thrown, then it may indicate the RocksDB is
         // already open in the container cache. As this code is only executed at

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/metadata/AbstractDatanodeStore.java

@@ -77,6 +77,7 @@ public abstract class AbstractDatanodeStore implements DatanodeStore {
   private static final DBProfile DEFAULT_PROFILE = DBProfile.DISK;
   private static final Map<ConfigurationSource, ColumnFamilyOptions>
       OPTIONS_CACHE = new ConcurrentHashMap<>();
+  private final boolean openReadOnly;
 
   /**
    * Constructs the metadata store and starts the DB services.
@@ -85,7 +86,8 @@ public abstract class AbstractDatanodeStore implements DatanodeStore {
    * @throws IOException - on Failure.
    */
   protected AbstractDatanodeStore(ConfigurationSource config, long containerID,
-      AbstractDatanodeDBDefinition dbDef) throws IOException {
+      AbstractDatanodeDBDefinition dbDef, boolean openReadOnly)
+      throws IOException {
 
     // The same config instance is used on each datanode, so we can share the
     // corresponding column family options, providing a single shared cache
@@ -97,6 +99,7 @@ protected AbstractDatanodeStore(ConfigurationSource config, long containerID,
 
     this.dbDef = dbDef;
     this.containerID = containerID;
+    this.openReadOnly = openReadOnly;
     start(config);
   }
 
@@ -121,6 +124,7 @@ public void start(ConfigurationSource config)
       this.store = DBStoreBuilder.newBuilder(config, dbDef)
               .setDBOptions(options)
               .setDefaultCFOptions(cfOptions)
+              .setOpenReadOnly(openReadOnly)
               .build();
 
       // Use the DatanodeTable wrapper to disable the table iterator on

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/metadata/DatanodeStoreSchemaOneImpl.java

@@ -35,9 +35,10 @@ public class DatanodeStoreSchemaOneImpl extends AbstractDatanodeStore {
    * @throws IOException - on Failure.
    */
   public DatanodeStoreSchemaOneImpl(ConfigurationSource config,
-                                    long containerID, String dbPath)
-          throws IOException {
-    super(config, containerID, new DatanodeSchemaOneDBDefinition(dbPath));
+      long containerID, String dbPath, boolean openReadOnly)
+      throws IOException {
+    super(config, containerID, new DatanodeSchemaOneDBDefinition(dbPath),
+        openReadOnly);
   }
 
   @Override

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/metadata/DatanodeStoreSchemaTwoImpl.java

@@ -37,8 +37,9 @@ public class DatanodeStoreSchemaTwoImpl extends AbstractDatanodeStore {
    * @throws IOException - on Failure.
    */
   public DatanodeStoreSchemaTwoImpl(ConfigurationSource config,
-                                    long containerID, String dbPath)
-          throws IOException {
-    super(config, containerID, new DatanodeSchemaTwoDBDefinition(dbPath));
+      long containerID, String dbPath, boolean openReadOnly)
+      throws IOException {
+    super(config, containerID, new DatanodeSchemaTwoDBDefinition(dbPath),
+        openReadOnly);
   }
 }

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/common/TestContainerCache.java

@@ -54,7 +54,7 @@ public class TestContainerCache {
   private void createContainerDB(OzoneConfiguration conf, File dbFile)
       throws Exception {
     DatanodeStore store = new DatanodeStoreSchemaTwoImpl(
-            conf, 1, dbFile.getAbsolutePath());
+            conf, 1, dbFile.getAbsolutePath(), false);
 
     // we close since the SCM pre-creates containers.
     // we will open and put Db handle into a cache when keys are being created

hadoop-hdds/framework/src/main/java/org/apache/hadoop/hdds/utils/db/DBStoreBuilder.java

@@ -87,6 +87,8 @@ public final class DBStoreBuilder {
   private CodecRegistry registry;
   private String rocksDbStat;
   private RocksDBConfiguration rocksDBConfiguration;
+  // Flag to indicate if the RocksDB should be opened readonly.
+  private boolean openReadOnly = false;
 
   /**
    * Create DBStoreBuilder from a generic DBDefinition.
@@ -187,7 +189,7 @@ public DBStore build() throws IOException {
     }
 
     return new RDBStore(dbFile, rocksDBOption, writeOptions, tableConfigs,
-        registry);
+        registry, openReadOnly);
   }
 
   public DBStoreBuilder setName(String name) {
@@ -227,6 +229,11 @@ public DBStoreBuilder setPath(Path path) {
     return this;
   }
 
+  public DBStoreBuilder setOpenReadOnly(boolean readOnly) {
+    this.openReadOnly = readOnly;
+    return this;
+  }
+
   /**
    * Set the {@link DBOptions} and default {@link ColumnFamilyOptions} based
    * on {@code prof}.

hadoop-hdds/framework/src/main/java/org/apache/hadoop/hdds/utils/db/RDBStore.java

@@ -71,12 +71,13 @@ public class RDBStore implements DBStore {
   @VisibleForTesting
   public RDBStore(File dbFile, DBOptions options,
                   Set<TableConfig> families) throws IOException {
-    this(dbFile, options, new WriteOptions(), families, new CodecRegistry());
+    this(dbFile, options, new WriteOptions(), families, new CodecRegistry(),
+        false);
   }
 
   public RDBStore(File dbFile, DBOptions options,
       WriteOptions writeOptions, Set<TableConfig> families,
-                  CodecRegistry registry)
+                  CodecRegistry registry, boolean readOnly)
       throws IOException {
     Preconditions.checkNotNull(dbFile, "DB file location cannot be null");
     Preconditions.checkNotNull(families);
@@ -108,8 +109,13 @@ public RDBStore(File dbFile, DBOptions options,
         extraCf.forEach(cf -> columnFamilyDescriptors.add(cf.getDescriptor()));
       }
 
-      db = RocksDB.open(dbOptions, dbLocation.getAbsolutePath(),
-          columnFamilyDescriptors, columnFamilyHandles);
+      if (readOnly) {
+        db = RocksDB.openReadOnly(dbOptions, dbLocation.getAbsolutePath(),
+            columnFamilyDescriptors, columnFamilyHandles);
+      } else {
+        db = RocksDB.open(dbOptions, dbLocation.getAbsolutePath(),
+            columnFamilyDescriptors, columnFamilyHandles);
+      }
 
       for (int x = 0; x < columnFamilyHandles.size(); x++) {
         handleTable.put(