5705: Explain metaspace in rule results

core/org.openjdk.jmc.flightrecorder.rules.jdk/src/main/java/org/openjdk/jmc/flightrecorder/rules/jdk/memory/IncreasingMetaspaceLiveSetRule.java

@@ -47,6 +47,7 @@
 import org.openjdk.jmc.common.item.IItemIterable;
 import org.openjdk.jmc.common.item.IMemberAccessor;
 import org.openjdk.jmc.common.item.ItemFilters;
+import org.openjdk.jmc.common.unit.BinaryPrefix;
 import org.openjdk.jmc.common.unit.IQuantity;
 import org.openjdk.jmc.common.unit.UnitLookup;
 import org.openjdk.jmc.common.util.IPreferenceValueProvider;
@@ -74,29 +75,36 @@ public class IncreasingMetaspaceLiveSetRule implements IRule {
 	private static final Map<String, EventAvailability> REQUIRED_EVENTS = RequiredEventsBuilder.create()
 			.addEventType(JdkTypeIDs.METASPACE_SUMMARY, EventAvailability.ENABLED).build();
 
+	public static final TypedResult<IQuantity> METASPACE_LIVESET_INCREASE = new TypedResult<>(
+			"metaspaceLivesetIncrease", //$NON-NLS-1$
+			"Metaspace Liveset Increase", "The speed of the metaspace liveset increase per second.", UnitLookup.MEMORY,
+			IQuantity.class);
+
 	private static final Collection<TypedResult<?>> RESULT_ATTRIBUTES = Arrays
-			.<TypedResult<?>> asList(TypedResult.SCORE);
+			.<TypedResult<?>> asList(TypedResult.SCORE, METASPACE_LIVESET_INCREASE);
 
 	private IResult getResult(
 		IItemCollection items, IPreferenceValueProvider valueProvider, IResultValueProvider resultProvider) {
 		IItemFilter afterFilter = ItemFilters.and(JdkFilters.METASPACE_SUMMARY_AFTER_GC, JdkFilters.AFTER_GC);
 		Iterator<? extends IItemIterable> allAfterItems = items.apply(afterFilter).iterator();
+		IQuantity metaspaceLiveSetIncreasePerSecond = UnitLookup.MEMORY.getUnit(BinaryPrefix.MEBI).quantity(0);
 		if (allAfterItems.hasNext()) {
 			IItemIterable afterItems = allAfterItems.next();
 			// FIXME: Handle multiple IItemIterable
 			IMemberAccessor<IQuantity, IItem> timeAccessor = JfrAttributes.END_TIME.getAccessor(afterItems.getType());
 			IMemberAccessor<IQuantity, IItem> memAccessor = JdkAttributes.GC_METASPACE_USED
 					.getAccessor(afterItems.getType());
 			double leastSquare = RulesToolkit.leastSquareMemory(afterItems.iterator(), timeAccessor, memAccessor);
+			metaspaceLiveSetIncreasePerSecond = UnitLookup.MEMORY.getUnit(BinaryPrefix.MEBI).quantity(leastSquare);
 			// FIXME: Configuration attribute
 			double score = RulesToolkit.mapExp100(leastSquare, 0.75);
-			// FIXME: Should construct a message using leastSquare, not use a hard limit
 			if (score >= 25) {
 				return ResultBuilder.createFor(this, valueProvider).setSeverity(Severity.get(score))
 						.setSummary(Messages.getString(Messages.IncreasingMetaspaceLiveSetRuleFactory_TEXT_INFO))
 						.setExplanation(
 								Messages.getString(Messages.IncreasingMetaspaceLiveSetRuleFactory_TEXT_INFO_LONG))
-						.addResult(TypedResult.SCORE, UnitLookup.NUMBER_UNITY.quantity(score)).build();
+						.addResult(TypedResult.SCORE, UnitLookup.NUMBER_UNITY.quantity(score))
+						.addResult(METASPACE_LIVESET_INCREASE, metaspaceLiveSetIncreasePerSecond).build();
 			}
 			return ResultBuilder.createFor(this, valueProvider).setSeverity(Severity.get(score))
 					.setSummary(Messages.getString(Messages.IncreasingMetaspaceLiveSetRuleFactory_TEXT_OK))

core/org.openjdk.jmc.flightrecorder.rules.jdk/src/main/java/org/openjdk/jmc/flightrecorder/rules/jdk/memory/MetaspaceOomRule.java

@@ -69,23 +69,42 @@ public class MetaspaceOomRule implements IRule {
 	public static final TypedResult<IQuantity> OOM_EVENTS = new TypedResult<>("oomCount", //$NON-NLS-1$
 			JdkAggregators.METASPACE_OOM_COUNT, UnitLookup.NUMBER, IQuantity.class);
 
+	public static final TypedResult<IQuantity> MAX_METASPACE_SIZE = new TypedResult<>("maxMetaspaceSize", //$NON-NLS-1$
+			"Maximum Metaspace Size", "The maximum size of the metaspace.", UnitLookup.NUMBER, IQuantity.class);
+
 	private static final Collection<TypedResult<?>> RESULT_ATTRIBUTES = Arrays
 			.<TypedResult<?>> asList(TypedResult.SCORE, OOM_EVENTS);
 
 	private IResult getResult(
 		IItemCollection items, IPreferenceValueProvider valueProvider, IResultValueProvider resultProvider) {
 		IQuantity oomCount = items.getAggregate(JdkAggregators.METASPACE_OOM_COUNT);
+		IQuantity maxMetaspaceSize = items.getAggregate(JdkAggregators.LARGEST_MAX_METASPACE_SIZE_FROM_FLAG);
 		if (oomCount != null && oomCount.doubleValue() > 0) {
 			// FIXME: Configuration attribute instead of hard coded 1 as warning limit
 			double score = RulesToolkit.mapExp100(oomCount.clampedLongValueIn(UnitLookup.NUMBER_UNITY), 1);
-			return ResultBuilder.createFor(this, valueProvider).setSeverity(Severity.get(score))
-					.setSummary(Messages.getString(Messages.MetaspaceOomRuleFactory_TEXT_WARN))
-					.setExplanation(Messages.getString(Messages.MetaspaceOomRuleFactory_TEXT_WARN_LONG))
+
+			ResultBuilder builder = ResultBuilder.createFor(this, valueProvider).setSeverity(Severity.get(score))
+					.setSummary(Messages.getString(Messages.MetaspaceOomRuleFactory_TEXT_CAUSE)
+							.concat(Messages.getString(Messages.MetaspaceOomRuleFactory_TEXT_WARN)))
 					.addResult(TypedResult.SCORE, UnitLookup.NUMBER_UNITY.quantity(score))
-					.addResult(OOM_EVENTS, oomCount).build();
+					.addResult(OOM_EVENTS, oomCount);
+
+			if (maxMetaspaceSize != null) {
+				builder.setExplanation(Messages.getString(Messages.MetaspaceOomRuleFactory_TEXT_INCREASE_ACTION)
+						.concat(Messages.getString(Messages.MetaspaceOomRuleFactory_TEXT_WARN_LONG)))
+						.addResult(MAX_METASPACE_SIZE, maxMetaspaceSize);
+			} else {
+				builder.setExplanation(Messages.getString(Messages.MetaspaceOomRuleFactory_TEXT_SET_ACTION)
+						.concat(Messages.getString(Messages.MetaspaceOomRuleFactory_TEXT_WARN_LONG)));
+			}
+
+			return builder.build();
+
 		}
 		return ResultBuilder.createFor(this, valueProvider).setSeverity(Severity.OK)
-				.setSummary(Messages.getString(Messages.MetaspaceOomRuleFactory_TEXT_OK)).build();
+				.setSummary(Messages.getString(Messages.MetaspaceOomRuleFactory_TEXT_CAUSE)
+						.concat(Messages.getString(Messages.MetaspaceOomRuleFactory_TEXT_OK)))
+				.build();
 	}
 
 	@Override

core/org.openjdk.jmc.flightrecorder.rules.jdk/src/main/java/org/openjdk/jmc/flightrecorder/rules/jdk/messages/internal/Messages.java

@@ -476,6 +476,9 @@ public class Messages {
 	public static final String ManyRunningProcessesRule_TEXT_RECOMMENDATION = "ManyRunningProcessesRule_TEXT_RECOMMENDATION"; //$NON-NLS-1$
 	public static final String MetaspaceOomRuleFactory_RULE_NAME = "MetaspaceOomRuleFactory_RULE_NAME"; //$NON-NLS-1$
 	public static final String MetaspaceOomRuleFactory_TEXT_OK = "MetaspaceOomRuleFactory_TEXT_OK"; //$NON-NLS-1$
+	public static final String MetaspaceOomRuleFactory_TEXT_CAUSE = "MetaspaceOomRuleFactory_TEXT_CAUSE"; //$NON-NLS-1$
+	public static final String MetaspaceOomRuleFactory_TEXT_SET_ACTION = "MetaspaceOomRuleFactory_TEXT_SET_ACTION"; //$NON-NLS-1$
+	public static final String MetaspaceOomRuleFactory_TEXT_INCREASE_ACTION = "MetaspaceOomRuleFactory_TEXT_INCREASE_ACTION"; //$NON-NLS-1$
 	public static final String MetaspaceOomRuleFactory_TEXT_WARN = "MetaspaceOomRuleFactory_TEXT_WARN"; //$NON-NLS-1$
 	public static final String MetaspaceOomRuleFactory_TEXT_WARN_LONG = "MetaspaceOomRuleFactory_TEXT_WARN_LONG"; //$NON-NLS-1$
 	public static final String MethodProfilingDataProvider_AGGR_AGGR_TOP_FRAME_QUOTA = "MethodProfilingDataProvider_AGGR_AGGR_TOP_FRAME_QUOTA"; //$NON-NLS-1$

core/org.openjdk.jmc.flightrecorder.rules.jdk/src/main/resources/org/openjdk/jmc/flightrecorder/rules/jdk/messages/internal/messages.properties

@@ -454,9 +454,10 @@ IncreasingLiveSetRuleFactory_RULE_NAME=Heap Live Set Trend
 IncreasingLiveSetRuleFactory_TEXT_INFO=The live set on the heap seems to increase with a speed of about {livesetIncrease} per second during the recording.
 IncreasingLiveSetRuleFactory_TEXT_INFO_LONG=This may be due to a memory leak in the application or it may be an artifact of a short recording if the JVM has recently been started. The recording began {timeAfterJvmStart} after the JVM was started. More information can be gathered by using the 'Old Object Sample' event, if available.
 IncreasingMetaspaceLiveSetRuleFactory_RULE_NAME=Metaspace Live Set Trend
-IncreasingMetaspaceLiveSetRuleFactory_TEXT_INFO=The class data seems to increase constantly in the metaspace during the recording.
+# {metaspaceLivesetIncrease} is a number denoted in Mebibytes per second
+IncreasingMetaspaceLiveSetRuleFactory_TEXT_INFO=Metaspace is the area of memory allocated for the JVM to store class metadata. The class metadata seems to increase constantly in the metaspace during the recording. The live set on the metaspace seems to increase with a speed of about {metaspaceLivesetIncrease} per second during the recording.
 IncreasingMetaspaceLiveSetRuleFactory_TEXT_INFO_LONG=This behavior may indicate a memory leak in the metaspace, this could be due to the application not unloading classes as needed.
-IncreasingMetaspaceLiveSetRuleFactory_TEXT_OK=The class data does not seem to increase during the recording.
+IncreasingMetaspaceLiveSetRuleFactory_TEXT_OK=Metaspace is the area of memory allocated for the JVM to store class metadata. The class metadata does not seem to increase during the recording.
 JavaBlocking_RULE_NAME=Java Blocking
 JavaBlockingRule_AGGR_BALANCE_BY_INSTANCE=By Instance
 JavaBlockingRule_AGGR_BALANCE_BY_THREAD=By Thread
@@ -519,10 +520,13 @@ ManyRunningProcessesRule_TEXT_RECOMMENDATION=If this is a server environment, it
 ManyRunningProcessesRule_INFO_LIMIT=Competing processes limit
 ManyRunningProcessesRule_INFO_LIMIT_LONG=The number of simultaneous processes needed to trigger an info notice
 MetaspaceOomRuleFactory_RULE_NAME=Metaspace Out of Memory
+MetaspaceOomRuleFactory_TEXT_CAUSE=Java class metadata is allocated in native memory (metaspace). When the amount of native memory needed for a class metadata exceeds MaxMetaspaceSize, a java.lang.OutOfMemoryError exception with a detail Metaspace is thrown. The amount of metaspace that can be used for class metadata is limited by the parameter MaxMetaspaceSize, which is specified on the command line.
+MetaspaceOomRuleFactory_TEXT_SET_ACTION=MaxMetaspaceSize has not been set on the command-line, setting its value may help resolve the issue. Metaspace is allocated from the same address spaces as the Java heap. Reducing the size of the Java heap will make more space available for MetaSpace.
+MetaspaceOomRuleFactory_TEXT_INCREASE_ACTION=MaxMetaspaceSize has been set to {maxMetaspaceSize} on the command-line, increase its value to resolve the issue. Metaspace is allocated from the same address spaces as the Java heap. Reducing the size of the Java heap will make more space available for MetaSpace.
 MetaspaceOomRuleFactory_TEXT_OK=The metaspace was not exhausted during this recording.
 # {oomCount} is a number
 MetaspaceOomRuleFactory_TEXT_WARN={oomCount} ''Out of Metaspace Memory'' events are present in this recording.
-MetaspaceOomRuleFactory_TEXT_WARN_LONG=Increase or remove the '-XX:MaxMetaSpaceSize' flag or investigate why classes are not unloaded properly.
+MetaspaceOomRuleFactory_TEXT_WARN_LONG=Increase or remove the '-XX:MaxMetaspaceSize' flag or investigate why classes are not unloaded properly.
 MethodProfilingDataProvider_AGGR_AGGR_TOP_FRAME_QUOTA=Top Frame Quota
 MethodProfilingDataProvider_AGGR_AGGR_TOP_FRAME_QUOTA_DESC=The quota between the top frame and the total samples count
 MethodProfilingDataProvider_AGGR_MAX_ENDTIME=Max End Time

core/org.openjdk.jmc.flightrecorder/src/main/java/org/openjdk/jmc/flightrecorder/jdk/JdkAggregators.java

@@ -236,6 +236,9 @@ public final class JdkAggregators {
 	public static final IAggregator<IQuantity, ?> LARGEST_MAX_HEAP_SIZE_FROM_FLAG = filter(
 			Messages.getString(Messages.AGGR_LARGEST_MAX_HEAP_SIZE_FROM_FLAG), null, max(ULONG_FLAG, FLAG_VALUE_NUMBER),
 			ItemFilters.equals(FLAG_NAME, "MaxHeapSize")); //$NON-NLS-1$
+	public static final IAggregator<IQuantity, ?> LARGEST_MAX_METASPACE_SIZE_FROM_FLAG = filter(
+			Messages.getString(Messages.AGGR_LARGEST_MAX_METASPACE_SIZE_FROM_FLAG), null,
+			max(ULONG_FLAG, FLAG_VALUE_NUMBER), ItemFilters.equals(FLAG_NAME, "MaxMetaspaceSize")); //$NON-NLS-1$
 	public static final IAggregator<IQuantity, ?> OUTSIDE_TLAB_COUNT = Aggregators.count(
 			Messages.getString(Messages.AGGR_OUTSIDE_TLAB_COUNT),
 			Messages.getString(Messages.AGGR_OUTSIDE_TLAB_COUNT_DESC), ALLOC_OUTSIDE_TLAB);

core/org.openjdk.jmc.flightrecorder/src/main/java/org/openjdk/jmc/flightrecorder/jdk/messages/internal/Messages.java

@@ -108,6 +108,7 @@ public class Messages {
 	public static final String AGGR_JFR_DATA_LOST_COUNT = "AGGR_JFR_DATA_LOST_COUNT"; //$NON-NLS-1$
 	public static final String AGGR_JFR_DATA_LOST_COUNT_DESC = "AGGR_JFR_DATA_LOST_COUNT_DESC"; //$NON-NLS-1$
 	public static final String AGGR_LARGEST_MAX_HEAP_SIZE_FROM_FLAG = "AGGR_LARGEST_MAX_HEAP_SIZE_FROM_FLAG"; //$NON-NLS-1$
+	public static final String AGGR_LARGEST_MAX_METASPACE_SIZE_FROM_FLAG = "AGGR_LARGEST_MAX_METASPACE_SIZE_FROM_FLAG"; //$NON-NLS-1$
 	public static final String AGGR_LAST_ATTRIBUTE = "AGGR_LAST_ATTRIBUTE"; //$NON-NLS-1$
 	public static final String AGGR_LAST_ATTRIBUTE_DESC = "AGGR_LAST_ATTRIBUTE_DESC"; //$NON-NLS-1$
 	public static final String AGGR_LONGEST_GC_PAUSE = "AGGR_LONGEST_GC_PAUSE"; //$NON-NLS-1$

core/org.openjdk.jmc.flightrecorder/src/main/resources/org/openjdk/jmc/flightrecorder/jdk/messages/internal/messages.properties

@@ -397,6 +397,7 @@ AGGR_IGNORE_UNRECOGNIZED_VM_OPTIONS=Ignore Unrecognized VM Options
 AGGR_ITEM_COUNT=Event Count
 AGGR_ITEM_COUNT_DESC=Total number of events
 AGGR_LARGEST_MAX_HEAP_SIZE_FROM_FLAG=Max Heap Size
+AGGR_LARGEST_MAX_METASPACE_SIZE_FROM_FLAG=Max Metaspace Size
 AGGR_LAST_ATTRIBUTE=Last {0}
 AGGR_LAST_ATTRIBUTE_DESC=The last value of {0} encountered
 AGGR_USING_COMPRESSED_OOPS=Using Compressed Oops

core/tests/org.openjdk.jmc.flightrecorder.rules.jdk.test/baseline/Generated_One_JfrRuleBaseline.xml

@@ -207,7 +207,7 @@ This recording is only 9.903 s long, consider creating a recording longer than
         <rule>
             <id>IncreasingMetaSpaceLiveSet</id>
             <severity>OK</severity>
-            <summary>The class data does not seem to increase during the recording.</summary>
+            <summary>Metaspace is the area of memory allocated for the JVM to store class metadata. The class metadata does not seem to increase during the recording.</summary>
         </rule>
         <rule>
             <id>JavaBlocking</id>
@@ -240,7 +240,7 @@ This recording is only 9.903 s long, consider creating a recording longer than
         <rule>
             <id>MetaspaceOom</id>
             <severity>OK</severity>
-            <summary>The metaspace was not exhausted during this recording.</summary>
+            <summary>Java class metadata is allocated in native memory (metaspace). When the amount of native memory needed for a class metadata exceeds MaxMetaSpaceSize, a java.lang.OutOfMemoryError exception with a detail MetaSpace is thrown. The amount of metaspace that can be used for class metadata is limited by the parameter MaxMetaSpaceSize, which is specified on the command line.The metaspace was not exhausted during this recording.</summary>
         </rule>
         <rule>
             <id>MethodProfiling</id>