Pipe: release resources of pipe event that have been GCed but the reference count is not zero by PhantomReference

iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/manager/pipe/agent/runtime/PipeConfigNodeRuntimeAgent.java

@@ -22,6 +22,7 @@
 import org.apache.iotdb.commons.exception.IllegalPathException;
 import org.apache.iotdb.commons.exception.pipe.PipeRuntimeCriticalException;
 import org.apache.iotdb.commons.exception.pipe.PipeRuntimeException;
+import org.apache.iotdb.commons.pipe.agent.runtime.PipePeriodicalJobExecutor;
 import org.apache.iotdb.commons.pipe.agent.task.meta.PipeTaskMeta;
 import org.apache.iotdb.commons.pipe.config.PipeConfig;
 import org.apache.iotdb.commons.pipe.event.EnrichedEvent;
@@ -45,6 +46,9 @@ public class PipeConfigNodeRuntimeAgent implements IService {
 
   private final AtomicBoolean isShutdown = new AtomicBoolean(false);
 
+  private final PipePeriodicalJobExecutor pipePeriodicalJobExecutor =
+      new PipePeriodicalJobExecutor();
+
   @Override
   public synchronized void start() {
     PipeConfig.getInstance().printAllConfigs();
@@ -58,6 +62,9 @@ public synchronized void start() {
     // Clean receiver file dir
     PipeConfigNodeAgent.receiver().cleanPipeReceiverDir();
 
+    // Start periodical job executor
+    pipePeriodicalJobExecutor.start();
+
     isShutdown.set(false);
     LOGGER.info("PipeRuntimeConfigNodeAgent started");
   }
@@ -69,6 +76,9 @@ public synchronized void stop() {
     }
     isShutdown.set(true);
 
+    // Stop periodical job executor
+    pipePeriodicalJobExecutor.stop();
+
     PipeConfigNodeAgent.task().dropAllPipeTasks();
 
     LOGGER.info("PipeRuntimeConfigNodeAgent stopped");
@@ -143,4 +153,10 @@ private void report(
       PipeConfigNodeAgent.task().stopAllPipesWithCriticalException();
     }
   }
+
+  /////////////////////////// Periodical Job Executor ///////////////////////////
+
+  public void registerPeriodicalJob(String id, Runnable periodicalJob, long intervalInSeconds) {
+    pipePeriodicalJobExecutor.register(id, periodicalJob, intervalInSeconds);
+  }
 }

iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/manager/pipe/event/PipeConfigRegionSnapshotEvent.java

@@ -24,9 +24,12 @@
 import org.apache.iotdb.commons.pipe.datastructure.pattern.TreePattern;
 import org.apache.iotdb.commons.pipe.event.EnrichedEvent;
 import org.apache.iotdb.commons.pipe.event.PipeSnapshotEvent;
+import org.apache.iotdb.commons.pipe.resource.ref.PipePhantomReferenceManager.PipeEventResource;
+import org.apache.iotdb.commons.pipe.resource.snapshot.PipeSnapshotResourceManager;
 import org.apache.iotdb.confignode.consensus.request.ConfigPhysicalPlanType;
 import org.apache.iotdb.confignode.manager.pipe.resource.PipeConfigNodeResourceManager;
 import org.apache.iotdb.confignode.persistence.schema.CNSnapshotFileType;
+import org.apache.iotdb.db.pipe.event.ReferenceTrackableEvent;
 
 import org.apache.tsfile.utils.ReadWriteIOUtils;
 import org.slf4j.Logger;
@@ -42,9 +45,12 @@
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.Collectors;
 
-public class PipeConfigRegionSnapshotEvent extends PipeSnapshotEvent {
+public class PipeConfigRegionSnapshotEvent extends PipeSnapshotEvent
+    implements ReferenceTrackableEvent {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(PipeConfigRegionSnapshotEvent.class);
   private String snapshotPath;
@@ -259,4 +265,53 @@ public String coreReportMessage() {
         + " - "
         + super.coreReportMessage();
   }
+
+  /////////////////////////// ReferenceTrackableEvent ///////////////////////////
+
+  @Override
+  protected void trackResource() {
+    PipeConfigNodeResourceManager.ref().trackPipeEventResource(this, eventResourceBuilder());
+  }
+
+  @Override
+  public PipeEventResource eventResourceBuilder() {
+    return new PipeConfigRegionSnapshotEventResource(
+        this.isReleased,
+        this.referenceCount,
+        this.resourceManager,
+        this.snapshotPath,
+        this.templateFilePath);
+  }
+
+  private static class PipeConfigRegionSnapshotEventResource extends PipeEventResource {
+
+    private final PipeSnapshotResourceManager resourceManager;
+    private final String snapshotPath;
+    private final String templateFilePath;
+
+    private PipeConfigRegionSnapshotEventResource(
+        final AtomicBoolean isReleased,
+        final AtomicInteger referenceCount,
+        final PipeSnapshotResourceManager resourceManager,
+        final String snapshotPath,
+        final String templateFilePath) {
+      super(isReleased, referenceCount);
+      this.resourceManager = resourceManager;
+      this.snapshotPath = snapshotPath;
+      this.templateFilePath = templateFilePath;
+    }
+
+    @Override
+    protected void finalizeResource() {
+      try {
+        resourceManager.decreaseSnapshotReference(snapshotPath);
+        if (!templateFilePath.isEmpty()) {
+          resourceManager.decreaseSnapshotReference(templateFilePath);
+        }
+      } catch (final Exception e) {
+        LOGGER.warn(
+            String.format("Decrease reference count for snapshot %s error.", snapshotPath), e);
+      }
+    }
+  }
 }

iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/manager/pipe/metric/PipeConfigNodeMetrics.java

@@ -43,6 +43,7 @@ public void bindTo(final AbstractMetricService metricService) {
     PipeConfigNodeRemainingTimeMetrics.getInstance().bindTo(metricService);
     PipeTemporaryMetaMetrics.getInstance().bindTo(metricService);
     PipeConfigNodeReceiverMetrics.getInstance().bindTo(metricService);
+    PipeConfigNodeResourceMetrics.getInstance().bindTo(metricService);
   }
 
   @Override
@@ -55,5 +56,6 @@ public void unbindFrom(final AbstractMetricService metricService) {
     PipeConfigNodeRemainingTimeMetrics.getInstance().unbindFrom(metricService);
     PipeTemporaryMetaMetrics.getInstance().unbindFrom(metricService);
     PipeConfigNodeReceiverMetrics.getInstance().unbindFrom(metricService);
+    PipeConfigNodeResourceMetrics.getInstance().unbindFrom(metricService);
   }
 }

iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/manager/pipe/metric/PipeConfigNodeResourceMetrics.java

@@ -0,0 +1,69 @@
+/*
+ * 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.iotdb.confignode.manager.pipe.metric;
+
+import org.apache.iotdb.commons.pipe.resource.ref.PipePhantomReferenceManager;
+import org.apache.iotdb.commons.service.metric.enums.Metric;
+import org.apache.iotdb.confignode.manager.pipe.resource.PipeConfigNodeResourceManager;
+import org.apache.iotdb.metrics.AbstractMetricService;
+import org.apache.iotdb.metrics.metricsets.IMetricSet;
+import org.apache.iotdb.metrics.utils.MetricLevel;
+import org.apache.iotdb.metrics.utils.MetricType;
+
+public class PipeConfigNodeResourceMetrics implements IMetricSet {
+
+  //////////////////////////// bindTo & unbindFrom (metric framework) ////////////////////////////
+
+  @Override
+  public void bindTo(final AbstractMetricService metricService) {
+    // phantom reference count
+    metricService.createAutoGauge(
+        Metric.PIPE_PHANTOM_REFERENCE_COUNT.toString(),
+        MetricLevel.IMPORTANT,
+        PipeConfigNodeResourceManager.ref(),
+        PipePhantomReferenceManager::getPhantomReferenceCount);
+  }
+
+  @Override
+  public void unbindFrom(final AbstractMetricService metricService) {
+    // phantom reference count
+    metricService.remove(MetricType.AUTO_GAUGE, Metric.PIPE_PHANTOM_REFERENCE_COUNT.toString());
+  }
+
+  //////////////////////////// singleton ////////////////////////////
+
+  private static class PipeConfigNodeResourceMetricsHolder {
+
+    private static final PipeConfigNodeResourceMetrics INSTANCE =
+        new PipeConfigNodeResourceMetrics();
+
+    private PipeConfigNodeResourceMetricsHolder() {
+      // empty constructor
+    }
+  }
+
+  public static PipeConfigNodeResourceMetrics getInstance() {
+    return PipeConfigNodeResourceMetrics.PipeConfigNodeResourceMetricsHolder.INSTANCE;
+  }
+
+  private PipeConfigNodeResourceMetrics() {
+    // empty constructor
+  }
+}

iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/manager/pipe/resource/PipeConfigNodeResourceManager.java

@@ -20,12 +20,15 @@
 package org.apache.iotdb.confignode.manager.pipe.resource;
 
 import org.apache.iotdb.commons.pipe.resource.log.PipeLogManager;
+import org.apache.iotdb.commons.pipe.resource.ref.PipePhantomReferenceManager;
 import org.apache.iotdb.commons.pipe.resource.snapshot.PipeSnapshotResourceManager;
+import org.apache.iotdb.confignode.manager.pipe.resource.ref.PipeConfigNodePhantomReferenceManager;
 
 public class PipeConfigNodeResourceManager {
 
   private final PipeSnapshotResourceManager pipeSnapshotResourceManager;
   private final PipeLogManager pipeLogManager;
+  private final PipePhantomReferenceManager pipePhantomReferenceManager;
 
   public static PipeSnapshotResourceManager snapshot() {
     return PipeConfigNodeResourceManager.PipeResourceManagerHolder.INSTANCE
@@ -36,11 +39,16 @@ public static PipeLogManager log() {
     return PipeConfigNodeResourceManager.PipeResourceManagerHolder.INSTANCE.pipeLogManager;
   }
 
+  public static PipePhantomReferenceManager ref() {
+    return PipeResourceManagerHolder.INSTANCE.pipePhantomReferenceManager;
+  }
+
   ///////////////////////////// SINGLETON /////////////////////////////
 
   private PipeConfigNodeResourceManager() {
     pipeSnapshotResourceManager = new PipeConfigNodeSnapshotResourceManager();
     pipeLogManager = new PipeLogManager();
+    pipePhantomReferenceManager = new PipeConfigNodePhantomReferenceManager();
   }
 
   private static class PipeResourceManagerHolder {

iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/manager/pipe/resource/ref/PipeConfigNodePhantomReferenceManager.java

@@ -0,0 +1,37 @@
+/*
+ * 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.iotdb.confignode.manager.pipe.resource.ref;
+
+import org.apache.iotdb.commons.pipe.config.PipeConfig;
+import org.apache.iotdb.commons.pipe.resource.ref.PipePhantomReferenceManager;
+import org.apache.iotdb.confignode.manager.pipe.agent.PipeConfigNodeAgent;
+
+public class PipeConfigNodePhantomReferenceManager extends PipePhantomReferenceManager {
+
+  public PipeConfigNodePhantomReferenceManager() {
+    super();
+
+    PipeConfigNodeAgent.runtime()
+        .registerPeriodicalJob(
+            "PipePhantomReferenceManager#gcHook()",
+            super::gcHook,
+            PipeConfig.getInstance().getPipeEventReferenceEliminateIntervalSeconds());
+  }
+}

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/pipe/agent/runtime/PipeDataNodeRuntimeAgent.java

@@ -25,6 +25,7 @@
 import org.apache.iotdb.commons.exception.StartupException;
 import org.apache.iotdb.commons.exception.pipe.PipeRuntimeCriticalException;
 import org.apache.iotdb.commons.exception.pipe.PipeRuntimeException;
+import org.apache.iotdb.commons.pipe.agent.runtime.PipePeriodicalJobExecutor;
 import org.apache.iotdb.commons.pipe.agent.task.meta.PipeTaskMeta;
 import org.apache.iotdb.commons.pipe.config.PipeConfig;
 import org.apache.iotdb.commons.pipe.event.EnrichedEvent;

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/pipe/event/ReferenceTrackableEvent.java

@@ -0,0 +1,27 @@
+/*
+ * 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.iotdb.db.pipe.event;
+
+import org.apache.iotdb.commons.pipe.resource.ref.PipePhantomReferenceManager.PipeEventResource;
+
+public interface ReferenceTrackableEvent {
+
+  PipeEventResource eventResourceBuilder();
+}