package com.codahale.metrics.jvm;
import com.codahale.metrics.Gauge;
import com.codahale.metrics.Metric;
import com.codahale.metrics.MetricSet;
import com.codahale.metrics.RatioGauge;
import java.lang.management.ManagementFactory;
import java.lang.management.MemoryMXBean;
import java.lang.management.MemoryPoolMXBean;
import java.lang.management.MemoryUsage;
import java.util.*;
import java.util.regex.Pattern;
import static com.codahale.metrics.MetricRegistry.name;
/**
* A set of gauges for JVM memory usage, including stats on heap vs. non-heap memory, plus
* GC-specific memory pools.
*/
public class MemoryUsageGaugeSet implements MetricSet {
private static final Pattern WHITESPACE = Pattern.compile("[\\s]+");
private final MemoryMXBean mxBean;
private final List<MemoryPoolMXBean> memoryPools;
public MemoryUsageGaugeSet() {
this(ManagementFactory.getMemoryMXBean(),
ManagementFactory.getMemoryPoolMXBeans());
}
public MemoryUsageGaugeSet(MemoryMXBean mxBean,
Collection<MemoryPoolMXBean> memoryPools) {
this.mxBean = mxBean;
this.memoryPools = new ArrayList<MemoryPoolMXBean>(memoryPools);
}
@Override
public Map<String, Metric> getMetrics() {
final Map<String, Metric> gauges = new HashMap<String, Metric>();
gauges.put("total.init", new Gauge<Long>() {
@Override
public Long getValue() {
return mxBean.getHeapMemoryUsage().getInit() +
mxBean.getNonHeapMemoryUsage().getInit();
}
});
gauges.put("total.used", new Gauge<Long>() {
@Override
public Long getValue() {
return mxBean.getHeapMemoryUsage().getUsed() +
mxBean.getNonHeapMemoryUsage().getUsed();
}
});
gauges.put("total.max", new Gauge<Long>() {
@Override
public Long getValue() {
return mxBean.getHeapMemoryUsage().getMax() +
mxBean.getNonHeapMemoryUsage().getMax();
}
});
gauges.put("total.committed", new Gauge<Long>() {
@Override
public Long getValue() {
return mxBean.getHeapMemoryUsage().getCommitted() +
mxBean.getNonHeapMemoryUsage().getCommitted();
}
});
gauges.put("heap.init", new Gauge<Long>() {
@Override
public Long getValue() {
return mxBean.getHeapMemoryUsage().getInit();
}
});
gauges.put("heap.used", new Gauge<Long>() {
@Override
public Long getValue() {
return mxBean.getHeapMemoryUsage().getUsed();
}
});
gauges.put("heap.max", new Gauge<Long>() {
@Override
public Long getValue() {
return mxBean.getHeapMemoryUsage().getMax();
}
});
gauges.put("heap.committed", new Gauge<Long>() {
@Override
public Long getValue() {
return mxBean.getHeapMemoryUsage().getCommitted();
}
});
gauges.put("heap.usage", new RatioGauge() {
@Override
protected Ratio getRatio() {
final MemoryUsage usage = mxBean.getHeapMemoryUsage();
return Ratio.of(usage.getUsed(), usage.getMax());
}
});
gauges.put("non-heap.init", new Gauge<Long>() {
@Override
public Long getValue() {
return mxBean.getNonHeapMemoryUsage().getInit();
}
});
gauges.put("non-heap.used", new Gauge<Long>() {
@Override
public Long getValue() {
return mxBean.getNonHeapMemoryUsage().getUsed();
}
});
gauges.put("non-heap.max", new Gauge<Long>() {
@Override
public Long getValue() {
return mxBean.getNonHeapMemoryUsage().getMax();
}
});
gauges.put("non-heap.committed", new Gauge<Long>() {
@Override
public Long getValue() {
return mxBean.getNonHeapMemoryUsage().getCommitted();
}
});
gauges.put("non-heap.usage", new RatioGauge() {
@Override
protected Ratio getRatio() {
final MemoryUsage usage = mxBean.getNonHeapMemoryUsage();
return Ratio.of(usage.getUsed(), usage.getMax());
}
});
for (final MemoryPoolMXBean pool : memoryPools) {
gauges.put(name("pools",
WHITESPACE.matcher(pool.getName()).replaceAll("-"),
"usage"),
new RatioGauge() {
@Override
protected Ratio getRatio() {
final long max = pool.getUsage().getMax() == -1 ?
pool.getUsage().getCommitted() :
pool.getUsage().getMax();
return Ratio.of(pool.getUsage().getUsed(), max);
}
});
}
return Collections.unmodifiableMap(gauges);
}
}