Java Code Examples for java.lang.management.MemoryPoolMXBean#getType()

/**
 * Gets the memory pool statistics from the JVM.
 *
 * @param poolBeans The collection of memory pool beans.
 * @return A string denoting the names and sizes of the memory pools.
 */
public static String getMemoryPoolStatsAsString(List<MemoryPoolMXBean> poolBeans) {
	StringBuilder bld = new StringBuilder("Off-heap pool stats: ");
	int count = 0;
	
	for (MemoryPoolMXBean bean : poolBeans) {
		if (bean.getType() == MemoryType.NON_HEAP) {
			if (count > 0) {
				bld.append(", ");
			}
			count++;

			MemoryUsage usage = bean.getUsage();
			long used = usage.getUsed() >> 20;
			long committed = usage.getCommitted() >> 20;
			long max = usage.getMax() >> 20;
			
			bld.append('[').append(bean.getName()).append(": ");
			bld.append(used).append('/').append(committed).append('/').append(max);
			bld.append(" MB (used/committed/max)]");
		}
	}

	return bld.toString();
}
 

/**
 * collect the pool division of java
 */
protected Map<String, Object> getPoolDivision() {
    if (LOG.isDebugEnabled()) {
        LOG.debug("==> RangerMetricsUtil.getPoolDivision()");
    }

    Map<String, Object> poolDivisionValues = new LinkedHashMap<>();
    for (MemoryPoolMXBean mpBean : ManagementFactory.getMemoryPoolMXBeans()) {
        if (mpBean.getType() == MemoryType.HEAP) {
            poolDivisionValues.put(mpBean.getName(), mpBean.getUsage());
        }
    }

    if (LOG.isDebugEnabled()) {
        LOG.debug("<== RangerMetricsUtil.getPoolDivision()" + poolDivisionValues);
    }

    return poolDivisionValues;
}
 

/**
 * collect the pool division of java
 */
protected Map<String, Object> getPoolDivision() {
    if (LOG.isDebugEnabled()) {
        LOG.debug("==> RangerJVMMetricUtil.getPoolDivision()");
    }

    Map<String, Object> poolDivisionValues = new LinkedHashMap<>();
    for (MemoryPoolMXBean mpBean : ManagementFactory.getMemoryPoolMXBeans()) {
        if (mpBean.getType() == MemoryType.HEAP) {
            poolDivisionValues.put(mpBean.getName(), mpBean.getUsage());
        }
    }

    if (LOG.isDebugEnabled()) {
        LOG.debug("<== RangerJVMMetricUtil.getPoolDivision()" + poolDivisionValues);
    }

    return poolDivisionValues;
}
 

/**
 * Determines if the name of the memory pool MXBean provided matches a list of
 * known tenured pool names.
 * 
 * Package private for testing.
 * 
 * @param memoryPoolMXBean
 *          The memory pool MXBean to check.
 * @return True if the pool name matches a known tenured pool name, false
 *         otherwise.
 */
static boolean isTenured(MemoryPoolMXBean memoryPoolMXBean) {
  if (memoryPoolMXBean.getType() != MemoryType.HEAP) {
    return false;
  }
  
  String name = memoryPoolMXBean.getName();
  
  return name.equals("CMS Old Gen")     // Sun Concurrent Mark Sweep GC
      || name.equals("PS Old Gen")      // Sun Parallel GC
      || name.equals("G1 Old Gen")      // Sun G1 GC
      || name.equals("Old Space")       // BEA JRockit 1.5, 1.6 GC
      || name.equals("Tenured Gen")     // Hitachi 1.5 GC
      || name.equals("Java heap")       // IBM 1.5, 1.6 GC
      
      // Allow an unknown pool name to monitor
      || (HEAP_POOL != null && name.equals(HEAP_POOL));
}
 

/**
 * Determines if the name of the memory pool MXBean provided matches a list of
 * known young generation pool names.
 * 
 * @param memoryPoolMXBean
 *          The memory pool MXBean to check.
 * @return True if the pool name matches a known young generation pool name,
 *         false otherwise.
 */
static boolean isEden(MemoryPoolMXBean memoryPoolMXBean) {
  if (memoryPoolMXBean.getType() != MemoryType.HEAP) {
    return false;
  }

  String name = memoryPoolMXBean.getName();

  return name.equals("Par Eden Space")  // Oracle ParNew with Concurrent Mark Sweep GC
      || name.equals("PS Eden Space")   // Oracle Parallel GC
      || name.equals("G1 Eden")         // Oracle G1 GC
      //|| name.equals("Nursery")       // BEA JRockit 1.5, 1.6 GC
      || name.equals("Eden Space")      // Hitachi 1.5 GC
      // Allow an unknown pool name to monitor
      || (HEAP_EDEN_POOL != null && name.equals(HEAP_EDEN_POOL));
}
 

/**
 * Determines if the name of the memory pool MXBean provided matches a list of
 * known tenured pool names.
 * 
 * Package private for testing.
 * 
 * @param memoryPoolMXBean
 *          The memory pool MXBean to check.
 * @return True if the pool name matches a known tenured pool name, false
 *         otherwise.
 */
static boolean isTenured(MemoryPoolMXBean memoryPoolMXBean) {
  if (memoryPoolMXBean.getType() != MemoryType.HEAP) {
    return false;
  }
  
  String name = memoryPoolMXBean.getName();
  
  return name.equals("CMS Old Gen")     // Sun Concurrent Mark Sweep GC
      || name.equals("PS Old Gen")      // Sun Parallel GC
      || name.equals("G1 Old Gen")      // Sun G1 GC
      || name.equals("Old Space")       // BEA JRockit 1.5, 1.6 GC
      || name.equals("Tenured Gen")     // Hitachi 1.5 GC
      || name.equals("Java heap")       // IBM 1.5, 1.6 GC
      
      // Allow an unknown pool name to monitor
      || (HEAP_POOL != null && name.equals(HEAP_POOL));
}
 

private void registerForNotifications() {
  // Register the listener with MemoryMXBean
  NotificationEmitter emitter = (NotificationEmitter) ManagementFactory.getMemoryMXBean();
  emitter.addNotificationListener(listener, null, null);

  // set collection usage threshold.
  for (MemoryPoolMXBean pool : ManagementFactory.getMemoryPoolMXBeans()) {
    if (pool.getType() == MemoryType.HEAP &&
      pool.isUsageThresholdSupported() &&
      pool.isCollectionUsageThresholdSupported()) {

      long threshold = (pool.getUsage().getMax() * thresholdPercentage) / 100;
      logger.info("setting collection threshold for " + pool.getName() +
        " with max " + pool.getUsage().getMax() +
        " to " + threshold);

      pool.setCollectionUsageThreshold(threshold);
      monitoredPools.put(pool.getName(), pool.getCollectionUsageThresholdCount());
    } else {
      logger.info("skip monitoring for pool " + pool.getName());
    }
  }
}
 

/**
 * Returns a summary information about the memory pools.
 */
public static String poolSummaries() {
    // Why ? list-archive?4273859
    // How ? http://stackoverflow.com/questions/697336/how-do-i-programmatically-find-out-my-permgen-space-usage
    //       http://stackoverflow.com/questions/8356416/xxmaxpermsize-with-or-without-xxpermsize
    StringBuilder sb = new StringBuilder();
    for (MemoryPoolMXBean item : ManagementFactory.getMemoryPoolMXBeans()) {
        String name = item.getName();
        MemoryType type = item.getType();
        MemoryUsage usage = item.getUsage();
        MemoryUsage peak = item.getPeakUsage();
        MemoryUsage collections = item.getCollectionUsage();
        sb.append("Memory pool name: " + name
                  + ", type: " + type
                  + ", usage: " + usage
                  + ", peak: " + peak
                  + ", collections: " + collections
                  + "\n");
    }
    return sb.toString();
}
 

@Override
public void run(SourceFunction.SourceContext<HeapMetrics> sourceContext) throws Exception {
	LOG.info("starting HeapMonitorSource");

	int subtaskIndex = this.getRuntimeContext().getIndexOfThisSubtask();
	String hostname = InetAddress.getLocalHost().getHostName();

	while (running) {
		Thread.sleep(sleepMillis);

		for (MemoryPoolMXBean mpBean : ManagementFactory.getMemoryPoolMXBeans()) {
			if (mpBean.getType() == MemoryType.HEAP) {
				MemoryUsage memoryUsage = mpBean.getUsage();
				long used = memoryUsage.getUsed();
				long max = memoryUsage.getMax();

				synchronized (sourceContext.getCheckpointLock()) {
					sourceContext.collect(new HeapMetrics(mpBean.getName(), used, max, (double) used / max, subtaskIndex, hostname));
				}
			}
		}
	}
}
 

/**
 * Gets the memory pool statistics from the JVM.
 *
 * @param poolBeans The collection of memory pool beans.
 * @return A string denoting the names and sizes of the memory pools.
 */
public static String getMemoryPoolStatsAsString(List<MemoryPoolMXBean> poolBeans) {
	StringBuilder bld = new StringBuilder("Off-heap pool stats: ");
	int count = 0;
	
	for (MemoryPoolMXBean bean : poolBeans) {
		if (bean.getType() == MemoryType.NON_HEAP) {
			if (count > 0) {
				bld.append(", ");
			}
			count++;

			MemoryUsage usage = bean.getUsage();
			long used = usage.getUsed() >> 20;
			long committed = usage.getCommitted() >> 20;
			long max = usage.getMax() >> 20;
			
			bld.append('[').append(bean.getName()).append(": ");
			bld.append(used).append('/').append(committed).append('/').append(max);
			bld.append(" MB (used/committed/max)]");
		}
	}

	return bld.toString();
}
 

/**
 * Determines if the name of the memory pool MXBean provided matches a list of
 * known survivor space pool names.
 * 
 * @param memoryPoolMXBean
 *          The memory pool MXBean to check.
 * @return True if the pool name matches a known survivor space pool name,
 *         false otherwise.
 */
static boolean isSurvivor(MemoryPoolMXBean memoryPoolMXBean) {
  if (memoryPoolMXBean.getType() != MemoryType.HEAP) {
    return false;
  }

  String name = memoryPoolMXBean.getName();

  return name.equals("Par Survivor Space")  // Oracle Concurrent Mark Sweep GC
      || name.equals("PS Survivor Space")   // Oracle Parallel GC
      || name.equals("G1 Survivor")         // Oracle G1 GC
      || name.equals("Survivor Space")      // Hitachi 1.5 GC
      // Allow an unknown pool name to monitor
      || (HEAP_SURVIVOR_POOL != null && name.equals(HEAP_SURVIVOR_POOL));
}
 

MemoryPoolMXBean getPermGenPool() {
    try {
        if (permGenPool == null) {
            JvmMXBeans jmx = getJvmMXBeans();
            if (jmx != null) {
                Collection<MemoryPoolMXBean> pools = jmx.getMemoryPoolMXBeans();
                for (MemoryPoolMXBean pool : pools) {
                    MemoryType type = pool.getType();
                    String name = pool.getName();
                    if (MemoryType.NON_HEAP.equals(type) &&
                            (PERM_GEN.equals(name) ||
                            PS_PERM_GEN.equals(name) ||
                            CMS_PERM_GEN.equals(name) ||
                            G1_PERM_GEN.equals(name) ||
                            METASPACE.equals(name) ||
                            IBM_PERM_GEN.equals(name))) {
                        permGenPool = pool;
                        break;
                    }
                }
            }
        }
        return permGenPool;
    } catch (Exception e) {
        LOGGER.throwing(JmxSupport.class.getName(), "getPermGenPool", e); // NOI18N
        return null;
    }
}
 

/**
 * collect the pool division of java
 */
private static void pooldivision(Map<String, Object> memory) {
    Map<String, Object> poolDivisionValues = new LinkedHashMap<>();
    for (MemoryPoolMXBean mpBean : ManagementFactory.getMemoryPoolMXBeans()) {
        if (mpBean.getType() == MemoryType.HEAP) {
            poolDivisionValues.put(mpBean.getName(), mpBean.getUsage());
        }
    }
    memory.put("memory_pool_usages", poolDivisionValues);
}
 

public void probeMemory() {
  long freeMemoryBytes = Runtime.getRuntime().freeMemory();
  long totalMemoryBytes = Runtime.getRuntime().totalMemory();
  long maxMemoryBytes = Runtime.getRuntime().maxMemory();

  long totalGcTimeMs = 0;
  for (GarbageCollectorMXBean gcMxBean : ManagementFactory.getGarbageCollectorMXBeans()) {
    long collectionTimeMs = gcMxBean.getCollectionTime();
    if (collectionTimeMs == -1) {
      // Gc collection time is not supported on this JVM.
      totalGcTimeMs = -1;
      break;
    }
    totalGcTimeMs += collectionTimeMs;
  }

  ImmutableMap.Builder<String, Long> currentMemoryBytesUsageByPool = ImmutableMap.builder();
  for (MemoryPoolMXBean memoryPoolBean : ManagementFactory.getMemoryPoolMXBeans()) {
    String name = memoryPoolBean.getName();
    MemoryType type = memoryPoolBean.getType();
    long currentlyUsedBytes = memoryPoolBean.getUsage().getUsed();
    currentMemoryBytesUsageByPool.put(name + "(" + type + ")", currentlyUsedBytes);
  }

  eventBus.post(
      new MemoryPerfStatsEvent(
          freeMemoryBytes,
          totalMemoryBytes,
          maxMemoryBytes,
          totalGcTimeMs,
          currentMemoryBytesUsageByPool.build()));
}
 

/**
 * Determines if the name of the memory pool MXBean provided matches a list of
 * known survivor space pool names.
 * 
 * @param memoryPoolMXBean
 *          The memory pool MXBean to check.
 * @return True if the pool name matches a known survivor space pool name,
 *         false otherwise.
 */
static boolean isSurvivor(MemoryPoolMXBean memoryPoolMXBean) {
  if (memoryPoolMXBean.getType() != MemoryType.HEAP) {
    return false;
  }

  String name = memoryPoolMXBean.getName();

  return name.equals("Par Survivor Space")  // Oracle Concurrent Mark Sweep GC
      || name.equals("PS Survivor Space")   // Oracle Parallel GC
      || name.equals("G1 Survivor")         // Oracle G1 GC
      || name.equals("Survivor Space")      // Hitachi 1.5 GC
      // Allow an unknown pool name to monitor
      || (HEAP_SURVIVOR_POOL != null && name.equals(HEAP_SURVIVOR_POOL));
}
 

/**
 * Tenured Space Pool can be determined by it being of type HEAP and by it
 * being possible to set the usage threshold.
 *
 * @return MXBean for the Tenured Space Pool
 */
private static MemoryPoolMXBean findTenuredGenPool() {
    // I don't know whether this approach is better, or whether
    // we should rather check for the pool name "Tenured Gen"?
    for (final MemoryPoolMXBean pool : ManagementFactory.getMemoryPoolMXBeans())
        if (pool.getType() == MemoryType.HEAP && pool.isUsageThresholdSupported()) {
            return pool;
        }
    throw new AssertionError("Could not find tenured space");
}
 

public static void setPercentageUsageThreshold(double percentage) {
    for (MemoryPoolMXBean pool : ManagementFactory.getMemoryPoolMXBeans()) {
        if (pool.getType() == MemoryType.HEAP && pool.isUsageThresholdSupported()) {
            if (percentage <= 0.0 || percentage > 1.0) {
                throw new IllegalArgumentException("percentage not in range");
            }
            long warningThreshold = (long) (pool.getUsage().getMax() * percentage);
            pool.setUsageThreshold(warningThreshold);
        }
    }
}
 

private static MemoryPoolMXBean findTenuredGenPool() {
    for (MemoryPoolMXBean pool : ManagementFactory.getMemoryPoolMXBeans()) {
        if (pool.getType() == MemoryType.HEAP && pool.isUsageThresholdSupported()) {
            return pool;
        }
    }
    throw new AssertionError("could not find tenured space");
}
 

/**
 * Tenured Space Pool can be determined by it being of type HEAP and by it
 * being possible to set the usage threshold.
 */
private static MemoryPoolMXBean findTenuredGenPool() {
	for (MemoryPoolMXBean pool : ManagementFactory.getMemoryPoolMXBeans()) {
		// I don't know whether this approach is better, or whether
		// we should rather check for the pool name "Tenured Gen"?
		if (pool.getType() == MemoryType.HEAP
				&& pool.isUsageThresholdSupported()) {
			return pool;
		}
	}
	throw new AssertionError("Could not find tenured space");
}
 

private SpillableMemoryManager() {
    ((NotificationEmitter)ManagementFactory.getMemoryMXBean()).addNotificationListener(this, null, null);
    List<MemoryPoolMXBean> mpbeans = ManagementFactory.getMemoryPoolMXBeans();
    MemoryPoolMXBean tenuredHeap = null;
    long tenuredHeapSize = 0;
    long totalSize = 0;
    for (MemoryPoolMXBean pool : mpbeans) {
        log.debug("Found heap (" + pool.getName() + ") of type " + pool.getType());
        if (pool.getType() == MemoryType.HEAP) {
            long size = pool.getUsage().getMax();
            totalSize += size;
            // CMS Old Gen or "tenured" is the only heap that supports
            // setting usage threshold.
            if (pool.isUsageThresholdSupported()) {
                tenuredHeapSize = size;
                tenuredHeap = pool;
            }
        }
    }
    extraGCSpillSizeThreshold  = (long) (totalSize * extraGCThresholdFraction);
    if (tenuredHeap == null) {
        throw new RuntimeException("Couldn't find heap");
    }
    log.debug("Selected heap to monitor (" +
        tenuredHeap.getName() + ")");

    // we want to set both collection and usage threshold alerts to be
    // safe. In some local tests after a point only collection threshold
    // notifications were being sent though usage threshold notifications
    // were sent early on. So using both would ensure that
    // 1) we get notified early (though usage threshold exceeded notifications)
    // 2) we get notified always when threshold is exceeded (either usage or
    //    collection)

    /* We set the threshold to be 50% of tenured since that is where
     * the GC starts to dominate CPU time according to Sun doc */
    tenuredHeap.setCollectionUsageThreshold((long)(tenuredHeapSize * collectionMemoryThresholdFraction));
    // we set a higher threshold for usage threshold exceeded notification
    // since this is more likely to be effective sooner and we do not
    // want to be spilling too soon
    tenuredHeap.setUsageThreshold((long)(tenuredHeapSize * memoryThresholdFraction));
}