/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.giraph.utils;
import org.apache.giraph.metrics.GiraphMetrics;
import org.apache.giraph.metrics.GiraphMetricsRegistry;
import org.apache.giraph.metrics.MetricNames;
import com.yammer.metrics.util.PercentGauge;
/**
* Helper static methods for tracking memory usage.
*/
public class MemoryUtils {
/** Do not instantiate. */
private MemoryUtils() { }
/**
* Helper to compute megabytes
* @param bytes integer number of bytes
* @return megabytes
*/
private static double megaBytes(long bytes) {
return bytes / 1024.0 / 1024.0;
}
/**
* Get total memory in megabytes
* @return total memory in megabytes
*/
public static double totalMemoryMB() {
return megaBytes(Runtime.getRuntime().totalMemory());
}
/**
* Get maximum memory in megabytes
* @return maximum memory in megabytes
*/
public static double maxMemoryMB() {
return megaBytes(Runtime.getRuntime().maxMemory());
}
/**
* Get free memory in megabytes
* @return free memory in megabytes
*/
public static double freeMemoryMB() {
return megaBytes(Runtime.getRuntime().freeMemory());
}
/**
* Initialize metrics tracked by this helper.
*/
public static void initMetrics() {
GiraphMetricsRegistry metrics = GiraphMetrics.get().perJobOptional();
metrics.getGauge(MetricNames.MEMORY_FREE_PERCENT, new PercentGauge() {
@Override
protected double getNumerator() {
return freeMemoryMB();
}
@Override
protected double getDenominator() {
return totalMemoryMB();
}
}
);
}
/**
* Get stringified runtime memory stats
*
* @return String of all Runtime stats.
*/
public static String getRuntimeMemoryStats() {
return String.format("Memory (free/total/max) = %.2fM / %.2fM / %.2fM",
freeMemoryMB(), totalMemoryMB(), maxMemoryMB());
}
}