GEODE-3583: Review comments

Applying fixes suggested by reviewers - removing and reducing the
visibility of some fields, adding comments.

extensions/geode-modules-session-internal/src/main/java/org/apache/geode/modules/session/internal/filter/Constants.java

@@ -20,9 +20,7 @@
  */
 public class Constants {
 
-  public static final String GEMFIRE_SESSION_REQUEST = "_gemfire_session_request_";
-
-  public static final String SESSION_STATISTICS_MBEAN_NAME =
+  static final String SESSION_STATISTICS_MBEAN_NAME =
       "org.apache:type=SessionStatistics,name=sessionStatistics";
 
 }

extensions/geode-modules-session/src/main/java/org/apache/geode/modules/session/filter/SessionCachingFilter.java

@@ -77,9 +77,6 @@ public class SessionCachingFilter implements Filter {
   private static final AtomicInteger started = new AtomicInteger(
       Integer.getInteger(DistributionConfig.GEMFIRE_PREFIX + "override.session.manager.count", 1));
 
-  private static final int percentInactiveTimeTriggerRebuild = Integer
-      .getInteger(DistributionConfig.GEMFIRE_PREFIX + "session.inactive.trigger.rebuild", 80);
-
   /**
    * This latch ensures that at least one thread/instance has fired up the session manager before
    * any other threads complete the init method.

geode-common/src/main/java/org/apache/geode/cache/ExpirationAction.java

@@ -164,7 +164,7 @@ public static ExpirationAction fromXmlString(String xmlValue) {
 
   // The 4 declarations below are necessary for serialization
   private static int nextOrdinal = 0;
-  public int ordinal = nextOrdinal++;
+  public final int ordinal = nextOrdinal++;
   private static final ExpirationAction[] VALUES =
       {INVALIDATE, LOCAL_INVALIDATE, DESTROY, LOCAL_DESTROY};
 

geode-core/src/main/java/org/apache/geode/cache/client/internal/ServerDenyList.java

@@ -56,7 +56,7 @@ public class ServerDenyList {
   protected final ListenerBroadcaster broadcaster = new ListenerBroadcaster();
 
   // not final for tests.
-  static final int THRESHOLD = Integer
+  private static final int THRESHOLD = Integer
       .getInteger(DistributionConfig.GEMFIRE_PREFIX + "ServerDenyList.THRESHOLD", 3).intValue();
   protected final long pingInterval;
 

geode-core/src/main/java/org/apache/geode/internal/cache/TombstoneService.java

@@ -323,13 +323,11 @@ public Object getBlockGCLock() {
 
   private static class Tombstone extends CompactVersionHolder {
     // tombstone overhead size
-    public static final int PER_TOMBSTONE_OVERHEAD = ReflectionSingleObjectSizer.REFERENCE_SIZE // queue's
-        // reference
-        // to the
-        // tombstone
-        + ReflectionSingleObjectSizer.REFERENCE_SIZE * 3 // entry, region, member ID
-        + ReflectionSingleObjectSizer.REFERENCE_SIZE // region entry value (Token.TOMBSTONE)
-        + 18; // version numbers and timestamp
+    public static final int PER_TOMBSTONE_OVERHEAD =
+        ReflectionSingleObjectSizer.REFERENCE_SIZE // queue's reference to the tombstone
+            + ReflectionSingleObjectSizer.REFERENCE_SIZE * 3 // entry, region, member ID
+            + ReflectionSingleObjectSizer.REFERENCE_SIZE // region entry value (Token.TOMBSTONE)
+            + 18; // version numbers and timestamp
 
 
     RegionEntry entry;

geode-core/src/main/java/org/apache/geode/internal/cache/versions/RegionVersionVector.java

@@ -61,10 +61,9 @@ public abstract class RegionVersionVector<T extends VersionSource<?>>
 
   private static final Logger logger = LogService.getLogger();
 
+  // TODO:LOG:CONVERT: REMOVE THIS
   public static final boolean DEBUG =
-      Boolean.getBoolean(DistributionConfig.GEMFIRE_PREFIX + "VersionVector.VERBOSE"); // TODO:LOG:CONVERT:
-  // REMOVE
-  // THIS
+      Boolean.getBoolean(DistributionConfig.GEMFIRE_PREFIX + "VersionVector.VERBOSE");