HDFS-14039. ec -listPolicies doesn't show correct state for the default policy when the default is not RS(6,3). Contributed by Kitti Nanasi.

Signed-off-by: Xiao Chen <xiao@apache.org>
(cherry picked from commit 8d99648c20)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/ErasureCodingPolicyManager.java

@@ -35,6 +35,7 @@ import org.apache.hadoop.util.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -80,6 +81,15 @@ public final class ErasureCodingPolicyManager {
    */
   private ErasureCodingPolicyInfo[] allPolicies;
 
+  /**
+   * All policies in the state as it will be persisted in the fsimage.
+   *
+   * The difference between persisted policies and all policies is that
+   * if a default policy is only enabled at startup,
+   * it will appear as disabled in the persisted policy list and in the fsimage.
+   */
+  private Map<Byte, ErasureCodingPolicyInfo> allPersistedPolicies;
+
   /**
    * All enabled policies sorted by name for fast querying, including built-in
    * policy, user defined policy.
@@ -90,6 +100,7 @@ public final class ErasureCodingPolicyManager {
    */
   private ErasureCodingPolicy[] enabledPolicies;
 
+  private String defaultPolicyName;
 
   private volatile static ErasureCodingPolicyManager instance = null;
 
@@ -102,14 +113,11 @@ public final class ErasureCodingPolicyManager {
 
   private ErasureCodingPolicyManager() {}
 
-  public void init(Configuration conf) {
+  public void init(Configuration conf) throws IOException {
-    // Load erasure coding default policy
-    final String defaultPolicyName = conf.getTrimmed(
-            DFSConfigKeys.DFS_NAMENODE_EC_SYSTEM_DEFAULT_POLICY,
-            DFSConfigKeys.DFS_NAMENODE_EC_SYSTEM_DEFAULT_POLICY_DEFAULT);
     this.policiesByName = new TreeMap<>();
     this.policiesByID = new TreeMap<>();
     this.enabledPoliciesByName = new TreeMap<>();
+    this.allPersistedPolicies = new TreeMap<>();
 
     /**
      * TODO: load user defined EC policy from fsImage HDFS-7859
@@ -125,31 +133,12 @@ public final class ErasureCodingPolicyManager {
       final ErasureCodingPolicyInfo info = new ErasureCodingPolicyInfo(policy);
       policiesByName.put(policy.getName(), info);
       policiesByID.put(policy.getId(), info);
+      allPersistedPolicies.put(policy.getId(),
+          new ErasureCodingPolicyInfo(policy));
     }
 
-    if (!defaultPolicyName.isEmpty()) {
+    enableDefaultPolicy(conf);
-      final ErasureCodingPolicyInfo info =
+    updatePolicies();
-          policiesByName.get(defaultPolicyName);
-      if (info == null) {
-        String names = policiesByName.values()
-            .stream().map((pi) -> pi.getPolicy().getName())
-            .collect(Collectors.joining(", "));
-        String msg = String.format("EC policy '%s' specified at %s is not a "
-                + "valid policy. Please choose from list of available "
-                + "policies: [%s]",
-            defaultPolicyName,
-            DFSConfigKeys.DFS_NAMENODE_EC_SYSTEM_DEFAULT_POLICY,
-            names);
-        throw new HadoopIllegalArgumentException(msg);
-      }
-      info.setState(ErasureCodingPolicyState.ENABLED);
-      enabledPoliciesByName.put(info.getPolicy().getName(), info.getPolicy());
-    }
-    enabledPolicies =
-        enabledPoliciesByName.values().toArray(new ErasureCodingPolicy[0]);
-    allPolicies =
-        policiesByName.values().toArray(new ErasureCodingPolicyInfo[0]);
-
     maxCellSize = conf.getInt(
         DFSConfigKeys.DFS_NAMENODE_EC_POLICIES_MAX_CELLSIZE_KEY,
         DFSConfigKeys.DFS_NAMENODE_EC_POLICIES_MAX_CELLSIZE_DEFAULT);
@@ -200,6 +189,21 @@ public final class ErasureCodingPolicyManager {
     return allPolicies;
   }
 
+  /**
+   * Get all system defined policies and user defined policies
+   * as it is written out in the fsimage.
+   *
+   * The difference between persisted policies and all policies is that
+   * if a default policy is only enabled at startup,
+   * it will appear as disabled in the persisted policy list and in the fsimage.
+   *
+   * @return persisted policies
+   */
+  public ErasureCodingPolicyInfo[] getPersistedPolicies() {
+    return allPersistedPolicies.values()
+        .toArray(new ErasureCodingPolicyInfo[0]);
+  }
+
   /**
    * Get a {@link ErasureCodingPolicy} by policy ID, including system policy
    * and user defined policy.
@@ -299,6 +303,8 @@ public final class ErasureCodingPolicyManager {
     this.policiesByID.put(policy.getId(), pi);
     allPolicies =
         policiesByName.values().toArray(new ErasureCodingPolicyInfo[0]);
+    allPersistedPolicies.put(policy.getId(),
+        new ErasureCodingPolicyInfo(policy));
     return policy;
   }
 
@@ -335,7 +341,8 @@ public final class ErasureCodingPolicyManager {
     }
     info.setState(ErasureCodingPolicyState.REMOVED);
     LOG.info("Remove erasure coding policy " + name);
-
+    allPersistedPolicies.put(ecPolicy.getId(),
+        createPolicyInfo(ecPolicy, ErasureCodingPolicyState.REMOVED));
     /*
      * TODO HDFS-12405 postpone the delete removed policy to Namenode restart
      * time.
@@ -370,6 +377,9 @@ public final class ErasureCodingPolicyManager {
           enabledPoliciesByName.values().toArray(new ErasureCodingPolicy[0]);
       info.setState(ErasureCodingPolicyState.DISABLED);
       LOG.info("Disable the erasure coding policy " + name);
+      allPersistedPolicies.put(info.getPolicy().getId(),
+          createPolicyInfo(info.getPolicy(),
+              ErasureCodingPolicyState.DISABLED));
       return true;
     }
     return false;
@@ -385,6 +395,12 @@ public final class ErasureCodingPolicyManager {
           name + " does not exist");
     }
     if (enabledPoliciesByName.containsKey(name)) {
+      if (defaultPolicyName.equals(name)) {
+        allPersistedPolicies.put(info.getPolicy().getId(),
+            createPolicyInfo(info.getPolicy(),
+                ErasureCodingPolicyState.ENABLED));
+        return true;
+      }
       return false;
     }
     final ErasureCodingPolicy ecPolicy = info.getPolicy();
@@ -392,6 +408,8 @@ public final class ErasureCodingPolicyManager {
     info.setState(ErasureCodingPolicyState.ENABLED);
     enabledPolicies =
         enabledPoliciesByName.values().toArray(new ErasureCodingPolicy[0]);
+    allPersistedPolicies.put(ecPolicy.getId(),
+        createPolicyInfo(info.getPolicy(), ErasureCodingPolicyState.ENABLED));
     LOG.info("Enable the erasure coding policy " + name);
     return true;
   }
@@ -414,6 +432,8 @@ public final class ErasureCodingPolicyManager {
     if (info.isEnabled()) {
       enablePolicy(policy.getName());
     }
+    allPersistedPolicies.put(policy.getId(),
+        createPolicyInfo(policy, info.getState()));
   }
 
   /**
@@ -423,11 +443,43 @@ public final class ErasureCodingPolicyManager {
    *
    */
   public synchronized void loadPolicies(
-      List<ErasureCodingPolicyInfo> ecPolicies) {
+      List<ErasureCodingPolicyInfo> ecPolicies, Configuration conf)
+      throws IOException{
     Preconditions.checkNotNull(ecPolicies);
     for (ErasureCodingPolicyInfo p : ecPolicies) {
       loadPolicy(p);
     }
+    enableDefaultPolicy(conf);
+    updatePolicies();
+  }
+
+  private void enableDefaultPolicy(Configuration conf) throws IOException {
+    defaultPolicyName = conf.getTrimmed(
+        DFSConfigKeys.DFS_NAMENODE_EC_SYSTEM_DEFAULT_POLICY,
+        DFSConfigKeys.DFS_NAMENODE_EC_SYSTEM_DEFAULT_POLICY_DEFAULT);
+    if (!defaultPolicyName.isEmpty()) {
+      final ErasureCodingPolicyInfo info =
+          policiesByName.get(defaultPolicyName);
+      if (info == null) {
+        String names = policiesByName.values()
+            .stream().map((pi) -> pi.getPolicy().getName())
+            .collect(Collectors.joining(", "));
+        String msg = String.format("EC policy '%s' specified at %s is not a "
+                + "valid policy. Please choose from list of available "
+                + "policies: [%s]",
+            defaultPolicyName,
+            DFSConfigKeys.DFS_NAMENODE_EC_SYSTEM_DEFAULT_POLICY,
+            names);
+        throw new IOException(msg);
+      }
+      info.setState(ErasureCodingPolicyState.ENABLED);
+      enabledPoliciesByName.put(info.getPolicy().getName(), info.getPolicy());
+    }
+  }
+
+  private void updatePolicies() {
+    enabledPolicies =
+        enabledPoliciesByName.values().toArray(new ErasureCodingPolicy[0]);
     allPolicies =
         policiesByName.values().toArray(new ErasureCodingPolicyInfo[0]);
   }
@@ -436,4 +488,11 @@ public final class ErasureCodingPolicyManager {
     return StringUtils.join(", ",
             enabledPoliciesByName.keySet());
   }
+
+  private ErasureCodingPolicyInfo createPolicyInfo(ErasureCodingPolicy p,
+                                                   ErasureCodingPolicyState s) {
+    ErasureCodingPolicyInfo policyInfo = new ErasureCodingPolicyInfo(p);
+    policyInfo.setState(s);
+    return policyInfo;
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSImageFormatProtobuf.java

@@ -380,7 +380,7 @@ public final class FSImageFormatProtobuf {
         ecPolicies.add(PBHelperClient.convertErasureCodingPolicyInfo(
             s.getPolicies(i)));
       }
-      fsn.getErasureCodingPolicyManager().loadPolicies(ecPolicies);
+      fsn.getErasureCodingPolicyManager().loadPolicies(ecPolicies, conf);
     }
   }
 
@@ -601,7 +601,7 @@ public final class FSImageFormatProtobuf {
         FileSummary.Builder summary) throws IOException {
       final FSNamesystem fsn = context.getSourceNamesystem();
       ErasureCodingPolicyInfo[] ecPolicies =
-          fsn.getErasureCodingPolicyManager().getPolicies();
+          fsn.getErasureCodingPolicyManager().getPersistedPolicies();
       ArrayList<ErasureCodingPolicyProto> ecPolicyProtoes =
           new ArrayList<ErasureCodingPolicyProto>();
       for (ErasureCodingPolicyInfo p : ecPolicies) {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeRpcServer.java

@@ -502,7 +502,7 @@ public class NameNodeRpcServer implements NamenodeProtocols {
         DFSConfigKeys.DFS_NAMENODE_MIN_SUPPORTED_DATANODE_VERSION_KEY,
         DFSConfigKeys.DFS_NAMENODE_MIN_SUPPORTED_DATANODE_VERSION_DEFAULT);
 
-    defaultECPolicyName = conf.get(
+    defaultECPolicyName = conf.getTrimmed(
         DFSConfigKeys.DFS_NAMENODE_EC_SYSTEM_DEFAULT_POLICY,
         DFSConfigKeys.DFS_NAMENODE_EC_SYSTEM_DEFAULT_POLICY_DEFAULT);
 

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestEnabledECPolicies.java

@@ -20,6 +20,8 @@ package org.apache.hadoop.hdfs.server.namenode;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.HdfsConfiguration;
 import org.apache.hadoop.hdfs.StripedFileTestUtil;
+import org.apache.hadoop.hdfs.protocol.ErasureCodingPolicyInfo;
+import org.apache.hadoop.hdfs.protocol.ErasureCodingPolicyState;
 import org.apache.hadoop.hdfs.protocol.SystemErasureCodingPolicies;
 import org.apache.hadoop.hdfs.protocol.ErasureCodingPolicy;
 import org.apache.hadoop.test.GenericTestUtils;
@@ -28,10 +30,16 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.Timeout;
 
+import java.io.IOException;
+import java.util.ArrayList;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 /**
@@ -43,14 +51,14 @@ public class TestEnabledECPolicies {
   @Rule
   public Timeout testTimeout = new Timeout(60000);
 
-  private void expectInvalidPolicy(String value) {
+  private void expectInvalidPolicy(String value) throws IOException {
     HdfsConfiguration conf = new HdfsConfiguration();
     conf.set(DFSConfigKeys.DFS_NAMENODE_EC_SYSTEM_DEFAULT_POLICY,
         value);
     try {
       ErasureCodingPolicyManager.getInstance().init(conf);
       fail("Expected exception when instantiating ECPolicyManager");
-    } catch (IllegalArgumentException e) {
+    } catch (IOException e) {
       GenericTestUtils.assertExceptionContains("is not a valid policy", e);
     }
   }
@@ -117,6 +125,70 @@ public class TestEnabledECPolicies {
     testGetPolicies(enabledPolicies);
   }
 
+  @Test
+  public void testChangeDefaultPolicy() throws Exception {
+    final HdfsConfiguration conf = new HdfsConfiguration();
+    final String testPolicy = "RS-3-2-1024k";
+    final String defaultPolicy = conf.getTrimmed(
+        DFSConfigKeys.DFS_NAMENODE_EC_SYSTEM_DEFAULT_POLICY,
+        DFSConfigKeys.DFS_NAMENODE_EC_SYSTEM_DEFAULT_POLICY_DEFAULT);
+    assertNotEquals("The default policy and the next default policy " +
+        "should not be the same!", testPolicy, defaultPolicy);
+
+    ErasureCodingPolicyManager manager =
+        ErasureCodingPolicyManager.getInstance();
+    // Change the default policy to a new one
+    conf.set(
+        DFSConfigKeys.DFS_NAMENODE_EC_SYSTEM_DEFAULT_POLICY,
+        testPolicy);
+    manager.init(conf);
+    // Load policies similar to when fsimage is loaded at namenode startup
+    manager.loadPolicies(constructAllDisabledInitialPolicies(), conf);
+
+    ErasureCodingPolicyInfo[] getPoliciesResult = manager.getPolicies();
+    boolean isEnabled = isPolicyEnabled(testPolicy, getPoliciesResult);
+    assertTrue("The new default policy should be " +
+        "in enabled state!", isEnabled);
+    ErasureCodingPolicyInfo[] getPersistedPoliciesResult
+        = manager.getPersistedPolicies();
+    isEnabled = isPolicyEnabled(testPolicy, getPersistedPoliciesResult);
+    assertFalse("The new default policy should be " +
+        "in disabled state in the persisted list!", isEnabled);
+
+    manager.disablePolicy(testPolicy);
+    getPoliciesResult = manager.getPolicies();
+    isEnabled = isPolicyEnabled(testPolicy, getPoliciesResult);
+    assertFalse("The new default policy should be " +
+        "in disabled state!", isEnabled);
+    getPersistedPoliciesResult
+        = manager.getPersistedPolicies();
+    isEnabled = isPolicyEnabled(testPolicy, getPersistedPoliciesResult);
+    assertFalse("The new default policy should be " +
+        "in disabled state in the persisted list!", isEnabled);
+
+    manager.enablePolicy(testPolicy);
+    getPoliciesResult = manager.getPolicies();
+    isEnabled = isPolicyEnabled(testPolicy, getPoliciesResult);
+    assertTrue("The new default policy should be " +
+        "in enabled state!", isEnabled);
+    getPersistedPoliciesResult
+        = manager.getPersistedPolicies();
+    isEnabled = isPolicyEnabled(testPolicy, getPersistedPoliciesResult);
+    assertTrue("The new default policy should be " +
+        "in enabled state in the persisted list!", isEnabled);
+
+    final String emptyPolicy = "";
+    // Change the default policy to a empty
+    conf.set(
+        DFSConfigKeys.DFS_NAMENODE_EC_SYSTEM_DEFAULT_POLICY, emptyPolicy);
+    manager.init(conf);
+    // Load policies similar to when fsimage is loaded at namenode startup
+    manager.loadPolicies(constructAllDisabledInitialPolicies(), conf);
+    // All the policies are disabled if the default policy is empty
+    getPoliciesResult = manager.getPolicies();
+    assertAllPoliciesAreDisabled(getPoliciesResult);
+  }
+
   private void testGetPolicies(ErasureCodingPolicy[] enabledPolicies)
       throws Exception {
     HdfsConfiguration conf = new HdfsConfiguration();
@@ -154,4 +226,31 @@ public class TestEnabledECPolicies {
       }
     }
   }
+
+  private List<ErasureCodingPolicyInfo> constructAllDisabledInitialPolicies() {
+    List<ErasureCodingPolicyInfo> policies = new ArrayList<>();
+    for (ErasureCodingPolicy p: SystemErasureCodingPolicies.getPolicies()) {
+      policies.add(new ErasureCodingPolicyInfo(p,
+          ErasureCodingPolicyState.DISABLED));
+    }
+    return policies;
+  }
+
+  private boolean isPolicyEnabled(String testPolicy,
+                               ErasureCodingPolicyInfo[] policies) {
+    for (ErasureCodingPolicyInfo p : policies) {
+      if (testPolicy.equals(p.getPolicy().getName())) {
+        return p.isEnabled();
+      }
+    }
+    fail("The result should contain the test policy!");
+    return false;
+  }
+
+  private void assertAllPoliciesAreDisabled(
+      ErasureCodingPolicyInfo[] policies) {
+    for (ErasureCodingPolicyInfo p : policies) {
+      assertTrue("Policy should be disabled", p.isDisabled());
+    }
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSImage.java

@@ -37,6 +37,7 @@ import java.util.EnumSet;
 import org.apache.hadoop.hdfs.StripedFileTestUtil;
 import org.apache.hadoop.hdfs.protocol.AddErasureCodingPolicyResponse;
 import org.apache.hadoop.hdfs.protocol.Block;
+import org.apache.hadoop.hdfs.protocol.ErasureCodingPolicyInfo;
 import org.apache.hadoop.hdfs.protocol.ErasureCodingPolicyState;
 import org.apache.hadoop.hdfs.protocol.SystemErasureCodingPolicies;
 import org.apache.hadoop.hdfs.protocol.ErasureCodingPolicy;
@@ -883,15 +884,19 @@ public class TestFSImage {
           DFSTestUtil.getECPolicyState(ecPolicy));
 
       // Test enable/disable/remove user customized erasure coding policy
-      testChangeErasureCodingPolicyState(cluster, blockSize, newPolicy);
+      testChangeErasureCodingPolicyState(cluster, blockSize, newPolicy, false);
-      // Test enable/disable built-in erasure coding policy
+      // Test enable/disable default built-in erasure coding policy
       testChangeErasureCodingPolicyState(cluster, blockSize,
-          SystemErasureCodingPolicies.getByID((byte) 1));
+          SystemErasureCodingPolicies.getByID((byte) 1), true);
+      // Test enable/disable non-default built-in erasure coding policy
+      testChangeErasureCodingPolicyState(cluster, blockSize,
+          SystemErasureCodingPolicies.getByID((byte) 2), false);
     }
   }
 
   private void testChangeErasureCodingPolicyState(MiniDFSCluster cluster,
-      int blockSize, ErasureCodingPolicy targetPolicy) throws IOException {
+      int blockSize, ErasureCodingPolicy targetPolicy, boolean isDefault)
+      throws IOException {
     DistributedFileSystem fs = cluster.getFileSystem();
 
     // 1. Enable an erasure coding policy
@@ -920,6 +925,9 @@ public class TestFSImage {
     assertEquals("The erasure coding policy should be of enabled state",
         ErasureCodingPolicyState.ENABLED,
         DFSTestUtil.getECPolicyState(ecPolicy));
+    assertTrue("Policy should be in disabled state in FSImage!",
+        isPolicyEnabledInFsImage(targetPolicy));
+
     // Read file regardless of the erasure coding policy state
     DFSTestUtil.readFileAsBytes(fs, filePath);
 
@@ -936,9 +944,18 @@ public class TestFSImage {
         ErasureCodingPolicyManager.getInstance().getByID(targetPolicy.getId());
     assertEquals("The erasure coding policy is not found",
         targetPolicy, ecPolicy);
-    assertEquals("The erasure coding policy should be of disabled state",
+    ErasureCodingPolicyState ecPolicyState =
-        ErasureCodingPolicyState.DISABLED,
+        DFSTestUtil.getECPolicyState(ecPolicy);
-        DFSTestUtil.getECPolicyState(ecPolicy));
+    if (isDefault) {
+      assertEquals("The erasure coding policy should be of " +
+              "enabled state", ErasureCodingPolicyState.ENABLED, ecPolicyState);
+    } else {
+      assertEquals("The erasure coding policy should be of " +
+          "disabled state", ErasureCodingPolicyState.DISABLED, ecPolicyState);
+    }
+    assertFalse("Policy should be in disabled state in FSImage!",
+        isPolicyEnabledInFsImage(targetPolicy));
+
     // Read file regardless of the erasure coding policy state
     DFSTestUtil.readFileAsBytes(fs, filePath);
 
@@ -972,4 +989,15 @@ public class TestFSImage {
     DFSTestUtil.readFileAsBytes(fs, filePath);
     fs.delete(dirPath, true);
   }
+
+  private boolean isPolicyEnabledInFsImage(ErasureCodingPolicy testPolicy) {
+    ErasureCodingPolicyInfo[] persistedPolicies =
+        ErasureCodingPolicyManager.getInstance().getPersistedPolicies();
+    for (ErasureCodingPolicyInfo p : persistedPolicies) {
+      if(p.getPolicy().getName().equals(testPolicy.getName())) {
+        return p.isEnabled();
+      }
+    }
+    throw new AssertionError("Policy is not found!");
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestNamenodeRetryCache.java

@@ -463,7 +463,7 @@ public class TestNamenodeRetryCache {
     assertTrue(namesystem.hasRetryCache());
     cacheSet = (LightWeightCache<CacheEntry, CacheEntry>) namesystem
         .getRetryCache().getCacheSet();
-    assertEquals("Retry cache size is wrong", 38, cacheSet.size());
+    assertEquals("Retry cache size is wrong", 39, cacheSet.size());
     iter = cacheSet.iterator();
     while (iter.hasNext()) {
       CacheEntry entry = iter.next();

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestStripedINodeFile.java

@@ -90,7 +90,7 @@ public class TestStripedINodeFile {
   public ExpectedException thrown = ExpectedException.none();
 
   @Before
-  public void init() {
+  public void init() throws IOException {
     Configuration conf = new HdfsConfiguration();
     ErasureCodingPolicyManager.getInstance().init(conf);
   }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/ha/TestRetryCacheWithHA.java

@@ -195,7 +195,7 @@ public class TestRetryCacheWithHA {
     FSNamesystem fsn1 = cluster.getNamesystem(1);
     cacheSet = (LightWeightCache<CacheEntry, CacheEntry>) fsn1
         .getRetryCache().getCacheSet();
-    assertEquals("Retry cache size is wrong", 38, cacheSet.size());
+    assertEquals("Retry cache size is wrong", 39, cacheSet.size());
     iter = cacheSet.iterator();
     while (iter.hasNext()) {
       CacheEntry entry = iter.next();