HDDS-14672. Remove SCM finalization checkpoints (#9955)

Author: sodonnel

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/ha/SCMContext.java

@@ -24,7 +24,6 @@
 import org.apache.hadoop.hdds.scm.safemode.SCMSafeModeManager.SafeModeStatus;
 import org.apache.hadoop.hdds.scm.server.OzoneStorageContainerManager;
 import org.apache.hadoop.hdds.scm.server.StorageContainerManager;
-import org.apache.hadoop.hdds.scm.server.upgrade.FinalizationCheckpoint;
 import org.apache.ratis.protocol.exceptions.NotLeaderException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -64,16 +63,10 @@ public final class SCMContext {
   private final OzoneStorageContainerManager scm;
   private final ReadWriteLock lock = new ReentrantReadWriteLock();
 
-  /**
-   * Tracks the last crossed SCM upgrade finalization checkpoint.
-   */
-  private volatile FinalizationCheckpoint finalizationCheckpoint;
-
   private SCMContext(Builder b) {
     isLeader = b.isLeader;
     term = b.term;
     safeModeStatus = b.safeModeStatus;
-    finalizationCheckpoint = b.finalizationCheckpoint;
     scm = b.scm;
     threadNamePrefix = b.threadNamePrefix;
   }
@@ -128,15 +121,6 @@ public void setLeaderReady() {
     }
   }
 
-  public void setFinalizationCheckpoint(FinalizationCheckpoint checkpoint) {
-    lock.writeLock().lock();
-    try {
-      this.finalizationCheckpoint = checkpoint;
-    } finally {
-      lock.writeLock().unlock();
-    }
-  }
-
   /**
    * Check whether current SCM is leader or not.
    *
@@ -246,15 +230,6 @@ public boolean isPreCheckComplete() {
     }
   }
 
-  public FinalizationCheckpoint getFinalizationCheckpoint() {
-    lock.readLock().lock();
-    try {
-      return this.finalizationCheckpoint;
-    } finally {
-      lock.readLock().unlock();
-    }
-  }
-
   /**
    * @return StorageContainerManager
    */
@@ -278,7 +253,6 @@ public static class Builder {
     private long term = INVALID_TERM;
     private SafeModeStatus safeModeStatus = SafeModeStatus.OUT_OF_SAFE_MODE;
     private OzoneStorageContainerManager scm = null;
-    private FinalizationCheckpoint finalizationCheckpoint = FinalizationCheckpoint.FINALIZATION_COMPLETE;
     private String threadNamePrefix = "";
 
     public Builder setLeader(boolean leader) {
@@ -302,12 +276,6 @@ public Builder setSCM(
       return this;
     }
 
-    public Builder setFinalizationCheckpoint(
-        FinalizationCheckpoint checkpoint) {
-      this.finalizationCheckpoint = checkpoint;
-      return this;
-    }
-
     public SCMContext.Builder setThreadNamePrefix(String prefix) {
       this.threadNamePrefix = prefix;
       return this;

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/ha/SCMStateMachine.java

@@ -391,7 +391,6 @@ public void notifyLeaderReady() {
     // leader ready  in SCMContext.
     scm.getScmContext().setLeaderReady();
     scm.getSCMServiceManager().notifyStatusChanged();
-    scm.getFinalizationManager().onLeaderReady();
   }
 
   @Override

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/node/SCMNodeManager.java

@@ -760,19 +760,14 @@ protected void sendFinalizeToDatanodeIfNeeded(DatanodeDetails datanodeDetails,
           datanodeDetails.getHostName(), dnSlv, scmSlv);
     }
 
-    if (FinalizationManager.shouldTellDatanodesToFinalize(
-        scmContext.getFinalizationCheckpoint())) {
-      // Because we have crossed the MLV_EQUALS_SLV checkpoint, SCM metadata
-      // layout version will not change. We can now compare it to the
-      // datanodes' metadata layout versions to tell them to finalize.
+    if (FinalizationManager.shouldTellDatanodesToFinalize(scmLayoutVersionManager)) {
+      // Because the finalizationManager / versionManager says finalization is not needed
+      // it means any DN that is reporting a metadata layout version less than the SCM's metadata layout version
+      // can be finalized.
       int scmMlv = scmLayoutVersionManager.getMetadataLayoutVersion();
 
-      // If the datanode mlv < scm mlv, it can not be allowed to be part of
-      // any pipeline. However it can be allowed to join the cluster
       if (dnMlv < scmMlv) {
-        LOG.warn("Data node {} can not be used in any pipeline in the " +
-                "cluster. " + "DataNode MetadataLayoutVersion = {}, SCM " +
-                "MetadataLayoutVersion = {}",
+        LOG.warn("Data node {} has a MetadataLayoutVersion = {}, SCM MetadataLayoutVersion = {}. Sending finalize",
             datanodeDetails.getHostName(), dnMlv, scmMlv);
 
         FinalizeNewLayoutVersionCommand finalizeCmd =

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/server/StorageContainerManager.java

@@ -730,7 +730,6 @@ private void initializeSystemManagers(OzoneConfiguration conf,
           .setSafeModeStatus(SCMSafeModeManager.SafeModeStatus.INITIAL)
           .setSCM(this)
           .setThreadNamePrefix(threadNamePrefix)
-          .setFinalizationCheckpoint(finalizationManager.getCheckpoint())
           .build();
     }
 

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/server/upgrade/FinalizationCheckpoint.java

@@ -42,18 +42,13 @@ UpgradeFinalization.StatusAndMessages queryUpgradeFinalizationProgress(
   BasicUpgradeFinalizer<SCMUpgradeFinalizationContext, HDDSLayoutVersionManager>
       getUpgradeFinalizer();
 
-  FinalizationCheckpoint getCheckpoint();
-
   void buildUpgradeContext(NodeManager nodeManager,
                                   SCMContext scmContext);
 
   void reinitialize(Table<String, String> finalizationStore) throws IOException;
 
-  void onLeaderReady();
-
-  static boolean shouldTellDatanodesToFinalize(
-      FinalizationCheckpoint checkpoint) {
-    return checkpoint.hasCrossed(FinalizationCheckpoint.MLV_EQUALS_SLV);
+  static boolean shouldTellDatanodesToFinalize(HDDSLayoutVersionManager versionManager) {
+    return !versionManager.needsFinalization();
   }
 
 }

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/server/upgrade/FinalizationManager.java

@@ -18,12 +18,9 @@
 package org.apache.hadoop.hdds.scm.server.upgrade;
 
 import com.google.common.annotations.VisibleForTesting;
-import com.google.common.util.concurrent.ThreadFactoryBuilder;
 import java.io.IOException;
 import java.util.Collections;
 import java.util.Objects;
-import java.util.concurrent.Executors;
-import java.util.concurrent.ThreadFactory;
 import org.apache.hadoop.hdds.scm.ha.SCMContext;
 import org.apache.hadoop.hdds.scm.ha.SCMHAManager;
 import org.apache.hadoop.hdds.scm.node.NodeManager;
@@ -34,22 +31,16 @@
 import org.apache.hadoop.ozone.upgrade.DefaultUpgradeFinalizationExecutor;
 import org.apache.hadoop.ozone.upgrade.UpgradeFinalization;
 import org.apache.hadoop.ozone.upgrade.UpgradeFinalizationExecutor;
-import org.apache.ratis.util.ExitUtils;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 /**
  * Class to initiate SCM finalization and query its progress.
  */
 public class FinalizationManagerImpl implements FinalizationManager {
-  private static final Logger LOG = LoggerFactory
-      .getLogger(FinalizationManagerImpl.class);
 
   private SCMUpgradeFinalizer upgradeFinalizer;
   private SCMUpgradeFinalizationContext context;
   private SCMStorageConfig storage;
   private final FinalizationStateManager finalizationStateManager;
-  private ThreadFactory threadFactory;
 
   /**
    * For test classes to inject their own state manager.
@@ -88,11 +79,6 @@ public void buildUpgradeContext(NodeManager nodeManager,
             .build();
 
     finalizationStateManager.setUpgradeContext(this.context);
-
-    String prefix = scmContext != null ? scmContext.threadNamePrefix() : "";
-    this.threadFactory = new ThreadFactoryBuilder()
-        .setNameFormat(prefix + "FinalizationManager-%d")
-        .build();
   }
 
   @Override
@@ -121,42 +107,12 @@ HDDSLayoutVersionManager> getUpgradeFinalizer() {
     return upgradeFinalizer;
   }
 
-  @Override
-  public FinalizationCheckpoint getCheckpoint() {
-    return finalizationStateManager.getFinalizationCheckpoint();
-  }
-
   @Override
   public void reinitialize(Table<String, String> finalizationStore)
       throws IOException {
     finalizationStateManager.reinitialize(finalizationStore);
   }
 
-  @Override
-  public void onLeaderReady() {
-    // Launch a background thread to drive finalization.
-    Executors.newSingleThreadExecutor(threadFactory).submit(() -> {
-      FinalizationCheckpoint currentCheckpoint = getCheckpoint();
-      if (currentCheckpoint.hasCrossed(
-          FinalizationCheckpoint.FINALIZATION_STARTED) &&
-          !currentCheckpoint.hasCrossed(
-              FinalizationCheckpoint.FINALIZATION_COMPLETE)) {
-        LOG.info("SCM became leader. Resuming upgrade finalization from" +
-            " current checkpoint {}.", currentCheckpoint);
-        try {
-          finalizeUpgrade("resume-finalization-as-leader");
-        } catch (IOException ex) {
-          ExitUtils.terminate(1,
-              "Resuming upgrade finalization failed on SCM leader change.",
-              ex, true, LOG);
-        }
-      } else if (LOG.isDebugEnabled()) {
-        LOG.debug("SCM became leader. No upgrade finalization action" +
-            " required for current checkpoint {}", currentCheckpoint);
-      }
-    });
-  }
-
   /**
    * Builds a {@link FinalizationManagerImpl}.
    */

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/server/upgrade/FinalizationManagerImpl.java

@@ -26,25 +26,10 @@
  */
 public interface FinalizationStateManager {
 
-  @Replicate
-  void addFinalizingMark() throws IOException;
-
-  @Replicate
-  void removeFinalizingMark() throws IOException;
-
   @Replicate
   void finalizeLayoutFeatures(Integer toLayoutVersion)
       throws IOException;
 
-  /**
-   * @param query The checkpoint to check for being crossed.
-   * @return true if SCM's disk state indicates this checkpoint has been
-   * crossed. False otherwise.
-   */
-  boolean crossedCheckpoint(FinalizationCheckpoint query);
-
-  FinalizationCheckpoint getFinalizationCheckpoint();
-
   void setUpgradeContext(SCMUpgradeFinalizationContext context);
 
   /**