HDDS-10156. Optimize Snapshot Cache get and eviction

hadoop-hdds/common/src/main/resources/ozone-default.xml

@@ -4282,7 +4282,7 @@
   </property>
 
   <property>
-    <name>ozone.om.snapshot.diff.cleanup.service.run.internal</name>
+    <name>ozone.om.snapshot.diff.cleanup.service.run.interval</name>
     <value>1m</value>
     <tag>OZONE, OM</tag>
     <description>
@@ -4301,6 +4301,16 @@
     </description>
   </property>
 
+  <property>
+    <name>ozone.om.snapshot.cache.cleanup.service.run.interval</name>
+    <value>1m</value>
+    <tag>OZONE, OM</tag>
+    <description>
+      Interval at which snapshot cache clean up will run.
+      Uses millisecond by default when no time unit is specified.
+    </description>
+  </property>
+
   <property>
     <name>ozone.om.snapshot.load.native.lib</name>
     <value>true</value>

hadoop-hdds/rocksdb-checkpoint-differ/src/main/java/org/apache/ozone/rocksdiff/RocksDBCheckpointDiffer.java

@@ -301,7 +301,7 @@ private void createSstBackUpDir() {
   }
 
   @Override
-  public void close() throws Exception {
+  public void close() {
     if (!closed) {
       synchronized (this) {
         if (!closed) {

hadoop-ozone/common/src/main/java/org/apache/hadoop/ozone/om/OMConfigKeys.java

@@ -569,13 +569,20 @@ private OMConfigKeys() {
       = TimeUnit.DAYS.toMillis(7);
 
   public static final String OZONE_OM_SNAPSHOT_DIFF_CLEANUP_SERVICE_RUN_INTERVAL
-      = "ozone.om.snapshot.diff.cleanup.service.run.internal";
+      = "ozone.om.snapshot.diff.cleanup.service.run.interval";
+  public static final String
+      OZONE_OM_SNAPSHOT_CACHE_CLEANUP_SERVICE_RUN_INTERVAL
+      = "ozone.om.snapshot.cache.cleanup.service.run.interval";
   public static final long
       OZONE_OM_SNAPSHOT_DIFF_CLEANUP_SERVICE_RUN_INTERVAL_DEFAULT
       = TimeUnit.MINUTES.toMillis(1);
+  public static final long
+      OZONE_OM_SNAPSHOT_CACHE_CLEANUP_SERVICE_RUN_INTERVAL_DEFAULT
+      = TimeUnit.MINUTES.toMillis(1);
 
   public static final String OZONE_OM_SNAPSHOT_DIFF_CLEANUP_SERVICE_TIMEOUT
       = "ozone.om.snapshot.diff.cleanup.service.timeout";
+
   public static final long
       OZONE_OM_SNAPSHOT_DIFF_CLEANUP_SERVICE_TIMEOUT_DEFAULT
       = TimeUnit.MINUTES.toMillis(5);

hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/OmSnapshot.java

@@ -47,6 +47,7 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.UUID;
 import java.util.stream.Collectors;
 
 /**
@@ -74,6 +75,7 @@ public class OmSnapshot implements IOmMetadataReader, Closeable {
   private final String volumeName;
   private final String bucketName;
   private final String snapshotName;
+  private final UUID snapshotID;
   // To access snapshot checkpoint DB metadata
   private final OMMetadataManager omMetadataManager;
   private final KeyManager keyManager;
@@ -83,7 +85,8 @@ public OmSnapshot(KeyManager keyManager,
                     OzoneManager ozoneManager,
                     String volumeName,
                     String bucketName,
-                    String snapshotName) {
+                    String snapshotName,
+                    UUID snapshotID) {
     IAccessAuthorizer accessAuthorizer =
         OzoneAuthorizerFactory.forSnapshot(ozoneManager,
             keyManager, prefixManager);
@@ -93,6 +96,7 @@ public OmSnapshot(KeyManager keyManager,
     this.snapshotName = snapshotName;
     this.bucketName = bucketName;
     this.volumeName = volumeName;
+    this.snapshotID = snapshotID;
     this.keyManager = keyManager;
     this.omMetadataManager = keyManager.getMetadataManager();
   }
@@ -295,6 +299,10 @@ public String getName() {
     return snapshotName;
   }
 
+  public UUID getSnapshotID() {
+    return snapshotID;
+  }
+
   @Override
   public void close() throws IOException {
     // Close DB

hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/OmSnapshotManager.java

@@ -83,6 +83,8 @@
 import static org.apache.hadoop.ozone.OzoneConsts.OM_SNAPSHOT_CHECKPOINT_DIR;
 import static org.apache.hadoop.ozone.OzoneConsts.OM_SNAPSHOT_DIFF_DB_NAME;
 import static org.apache.hadoop.ozone.OzoneConsts.OM_SNAPSHOT_INDICATOR;
+import static org.apache.hadoop.ozone.om.OMConfigKeys.OZONE_OM_SNAPSHOT_CACHE_CLEANUP_SERVICE_RUN_INTERVAL;
+import static org.apache.hadoop.ozone.om.OMConfigKeys.OZONE_OM_SNAPSHOT_CACHE_CLEANUP_SERVICE_RUN_INTERVAL_DEFAULT;
 import static org.apache.hadoop.ozone.om.OMConfigKeys.OZONE_OM_SNAPSHOT_CACHE_MAX_SIZE;
 import static org.apache.hadoop.ozone.om.OMConfigKeys.OZONE_OM_SNAPSHOT_CACHE_MAX_SIZE_DEFAULT;
 import static org.apache.hadoop.ozone.om.OMConfigKeys.OZONE_OM_SNAPSHOT_DB_MAX_OPEN_FILES;
@@ -272,7 +274,12 @@ public OmSnapshotManager(OzoneManager ozoneManager) {
     };
 
     // Init snapshot cache
-    this.snapshotCache = new SnapshotCache(loader, softCacheSize, ozoneManager.getMetrics());
+    long cacheCleanupServiceInterval = ozoneManager.getConfiguration()
+        .getTimeDuration(OZONE_OM_SNAPSHOT_CACHE_CLEANUP_SERVICE_RUN_INTERVAL,
+            OZONE_OM_SNAPSHOT_CACHE_CLEANUP_SERVICE_RUN_INTERVAL_DEFAULT,
+            TimeUnit.MILLISECONDS);
+    this.snapshotCache = new SnapshotCache(loader, softCacheSize, ozoneManager.getMetrics(),
+        cacheCleanupServiceInterval);
 
     this.snapshotDiffManager = new SnapshotDiffManager(snapshotDiffDb, differ,
         ozoneManager, snapDiffJobCf, snapDiffReportCf,
@@ -382,7 +389,8 @@ public OmSnapshot load(@Nonnull UUID snapshotId) throws IOException {
           return new OmSnapshot(km, pm, ozoneManager,
               snapshotInfo.getVolumeName(),
               snapshotInfo.getBucketName(),
-              snapshotInfo.getName());
+              snapshotInfo.getName(),
+              snapshotInfo.getSnapshotId());
         } catch (Exception e) {
           // Close RocksDB if there is any failure.
           if (!snapshotMetadataManager.getStore().isClosed()) {
@@ -418,6 +426,7 @@ public int getSnapshotCacheSize() {
   public void invalidateCache() {
     if (snapshotCache != null) {
       snapshotCache.invalidateAll();
+      snapshotCache.close();
     }
   }
 
@@ -426,7 +435,7 @@ public void invalidateCache() {
    *
    * @param key SnapshotId.
    */
-  public void invalidateCacheEntry(UUID key) throws IOException {
+  public void invalidateCacheEntry(UUID key) {
     if (snapshotCache != null) {
       snapshotCache.invalidate(key);
     }

hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/snapshot/ReferenceCounted.java

@@ -51,10 +51,10 @@ public class ReferenceCounted<T>
   /**
    * Parent instance whose callback will be triggered upon this RC closure.
    */
-  private final Object parentWithCallback;
+  private final ReferenceCountedCallback parentWithCallback;
 
   public ReferenceCounted(T obj, boolean disableCounter,
-      Object parentWithCallback) {
+      ReferenceCountedCallback parentWithCallback) {
     // A param to allow disabling ref counting to reduce active DB
     //  access penalties due to AtomicLong operations.
     this.obj = obj;
@@ -126,7 +126,9 @@ public long decrementRefCount() {
       Preconditions.checkState(newValTotal >= 0L,
           "Total reference count underflow");
     }
-
+    if (refCount.get() == 0) {
+      this.parentWithCallback.callback(this);
+    }
     return refCount.get();
   }
 

hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/snapshot/ReferenceCountedCallback.java

@@ -0,0 +1,25 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ *  with the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.apache.hadoop.ozone.om.snapshot;
+
+/**
+ * Callback interface for ReferenceCounted.
+ */
+public interface ReferenceCountedCallback {
+  void callback(ReferenceCounted referenceCounted);
+}