GEODE-10206: clean up product references to CMS (#7646)

* the command line validator no longer warns if CMS is not configured if the JDK does not support CMS
* cleaned up comments that refer to CMS

extensions/geode-modules/build.gradle

@@ -37,6 +37,7 @@ dependencies {
   compileOnly('javax.servlet:javax.servlet-api')
   compileOnly('org.apache.tomcat:catalina-ha:' + DependencyConstraints.get('tomcat6.version'))
 
+  implementation('org.apache.commons:commons-lang3')
 
   // test
   testImplementation('org.apache.bcel:bcel')

extensions/geode-modules/src/main/java/org/apache/geode/modules/session/bootstrap/AbstractCache.java

@@ -363,9 +363,8 @@ private void initializeResourceManager() {
       }
     }
 
-    // Validate java startup parameters (done after setting the eviction and
-    // critical heap percentages so that the CMSInitiatingOccupancyFraction can
-    // be compared against them.
+    // Validate java startup parameters after setting the eviction and
+    // critical heap percentages so that they can be compared against them.
     ResourceManagerValidator.validateJavaStartupParameters(getCache());
   }
 

extensions/geode-modules/src/main/java/org/apache/geode/modules/util/ResourceManagerValidator.java

@@ -14,6 +14,9 @@
  */
 package org.apache.geode.modules.util;
 
+import static org.apache.commons.lang3.JavaVersion.JAVA_13;
+import static org.apache.commons.lang3.SystemUtils.isJavaVersionAtMost;
+
 import java.lang.management.ManagementFactory;
 import java.lang.management.RuntimeMXBean;
 import java.util.ArrayList;
@@ -106,15 +109,22 @@ private static void validateJavaHeapParameters(GemFireCache cache, String dashXm
     }
   }
 
+  private static boolean isCMSAvailable() {
+    return isJavaVersionAtMost(JAVA_13);
+  }
+
   private static void verifyCMSGC(GemFireCache cache, String useCMS) {
-    if (useCMS == null) {
+    if (useCMS == null && isCMSAvailable()) {
       cache.getLogger().warning(
           "Using the concurrent garbage collector (configured using -XX:+UseConcMarkSweepGC) is recommended so that GemFire cache eviction is optimal");
     }
   }
 
   private static void verifyCMSInitiatingOccupancyFraction(GemFireCache cache, ResourceManager rm,
       String cmsIOF) {
+    if (!isCMSAvailable()) {
+      return;
+    }
     if (cmsIOF == null) {
       cache.getLogger().warning(
           "Setting the CMS initiating occupancy fraction (configured using -XX:CMSInitiatingOccupancyFraction=N) is recommended so that GemFire cache eviction is optimal");

extensions/geode-modules/src/test/resources/expected-pom.xml

@@ -76,5 +76,10 @@
       <artifactId>slf4j-api</artifactId>
       <scope>runtime</scope>
     </dependency>
+    <dependency>
+      <groupId>org.apache.commons</groupId>
+      <artifactId>commons-lang3</artifactId>
+      <scope>runtime</scope>
+    </dependency>
   </dependencies>
 </project>

geode-core/src/main/java/org/apache/geode/cache/EvictionAttributes.java

@@ -155,8 +155,9 @@ public static EvictionAttributes createLRUEntryAttributes(int maximumEntries,
    * switches to control the behavior of the garbage collector. We suggest that you investigate
    * tuning the garbage collector when using this type of eviction controller. A collector that
    * frequently collects is needed to keep our heap usage up to date. In particular, on the Sun
-   * <A href="http://java.sun.com/docs/hotspot/gc/index.html">HotSpot</a> JVM, the
-   * <code>-XX:+UseConcMarkSweepGC</code> flag needs to be set, and
+   * <A href="http://java.sun.com/docs/hotspot/gc/index.html">HotSpot</a> JVM,
+   * before Java 14,
+   * the <code>-XX:+UseConcMarkSweepGC</code> flag needs to be set, and
    * <code>-XX:CMSInitiatingOccupancyFraction=N</code> should be set with N being a percentage that
    * is less than the {@link ResourceManager} eviction heap threshold.
    * <p>

geode-core/src/main/java/org/apache/geode/cache/control/ResourceManager.java

@@ -127,8 +127,9 @@ public interface ResourceManager {
    * additional VM switches to control the behavior of the garbage collector. We suggest that you
    * investigate tuning the garbage collector when using this type of eviction controller. A
    * collector that frequently collects is needed to keep our heap usage up to date. In particular,
-   * on the Sun <A href="http://java.sun.com/docs/hotspot/gc/index.html">HotSpot</a> VM, the
-   * <code>-XX:+UseConcMarkSweepGC</code> flag needs to be set, and
+   * on the Sun <A href="http://java.sun.com/docs/hotspot/gc/index.html">HotSpot</a> VM,
+   * before Java 14,
+   * the <code>-XX:+UseConcMarkSweepGC</code> flag needs to be set, and
    * <code>-XX:CMSInitiatingOccupancyFraction=N</code> should be set with N being a percentage that
    * is less than the {@link ResourceManager} critical and eviction heap thresholds.
    *