return clusterNodeMap;
}
+ /**
+ * Reset all {@link ClusterNode}s. Reset is needed when {@link IntervalProperty#INTERVAL} or
+ * {@link SampleCountProperty#SAMPLE_COUNT} is changed.
+ */
+ public static void resetClusterNodes() {
+ for (ClusterNode node : clusterNodeMap.values()) {
+ node.reset();
+ }
+ }
}
diff --git a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/base/LeapArray.java b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/base/LeapArray.java
index f3469161..30761e2f 100755
--- a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/base/LeapArray.java
+++ b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/base/LeapArray.java
@@ -23,15 +23,23 @@ import java.util.concurrent.locks.ReentrantLock;
import com.alibaba.csp.sentinel.util.TimeUtil;
/**
+ *
* Basic data structure for statistic metrics.
+ *
+ *
+ * Using sliding window algorithm to count data. Each bucket cover {@link #windowLengthInMs} time span,
+ * and the total time span is {@link #intervalInMs}, so the total bucket count is:
+ * {@link #sampleCount} = intervalInMs / windowLengthInMs.
+ *
*
- * @param type of data wrapper
+ * @param type of data bucket.
* @author jialiang.linjl
* @author Eric Zhao
+ * @author CarpenterLee
*/
public abstract class LeapArray {
- protected int windowLength;
+ protected int windowLengthInMs;
protected int sampleCount;
protected int intervalInMs;
@@ -39,10 +47,15 @@ public abstract class LeapArray {
private final ReentrantLock updateLock = new ReentrantLock();
- public LeapArray(int windowLength, int intervalInSec) {
- this.windowLength = windowLength;
+ /**
+ * The total bucket count is: {@link #sampleCount} = intervalInSec * 1000 / windowLengthInMs.
+ * @param windowLengthInMs a single window bucket's time length in milliseconds.
+ * @param intervalInSec the total time span of this {@link LeapArray} in seconds.
+ */
+ public LeapArray(int windowLengthInMs, int intervalInSec) {
+ this.windowLengthInMs = windowLengthInMs;
this.intervalInMs = intervalInSec * 1000;
- this.sampleCount = intervalInMs / windowLength;
+ this.sampleCount = intervalInMs / windowLengthInMs;
this.array = new AtomicReferenceArray>(sampleCount);
}
@@ -79,17 +92,17 @@ public abstract class LeapArray {
* @return the window at provided timestamp
*/
public WindowWrap currentWindow(long time) {
- long timeId = time / windowLength;
+ long timeId = time / windowLengthInMs;
// Calculate current index.
int idx = (int)(timeId % array.length());
// Cut the time to current window start.
- time = time - time % windowLength;
+ time = time - time % windowLengthInMs;
while (true) {
WindowWrap old = array.get(idx);
if (old == null) {
- WindowWrap window = new WindowWrap(windowLength, time, newEmptyBucket());
+ WindowWrap window = new WindowWrap(windowLengthInMs, time, newEmptyBucket());
if (array.compareAndSet(idx, null, window)) {
return window;
} else {
@@ -111,22 +124,22 @@ public abstract class LeapArray {
} else if (time < old.windowStart()) {
// Cannot go through here.
- return new WindowWrap(windowLength, time, newEmptyBucket());
+ return new WindowWrap(windowLengthInMs, time, newEmptyBucket());
}
}
}
public WindowWrap getPreviousWindow(long time) {
- long timeId = (time - windowLength) / windowLength;
+ long timeId = (time - windowLengthInMs) / windowLengthInMs;
int idx = (int)(timeId % array.length());
- time = time - windowLength;
+ time = time - windowLengthInMs;
WindowWrap wrap = array.get(idx);
if (wrap == null || isWindowDeprecated(wrap)) {
return null;
}
- if (wrap.windowStart() + windowLength < (time)) {
+ if (wrap.windowStart() + windowLengthInMs < (time)) {
return null;
}
@@ -138,7 +151,7 @@ public abstract class LeapArray {
}
public T getWindowValue(long time) {
- long timeId = time / windowLength;
+ long timeId = time / windowLengthInMs;
int idx = (int)(timeId % array.length());
WindowWrap old = array.get(idx);
diff --git a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/base/WindowWrap.java b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/base/WindowWrap.java
index e8529669..5818e4ba 100755
--- a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/base/WindowWrap.java
+++ b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/base/WindowWrap.java
@@ -25,9 +25,9 @@ package com.alibaba.csp.sentinel.slots.statistic.base;
public class WindowWrap {
/**
- * The length of the window.
+ * a single window bucket's time length in milliseconds.
*/
- private final long windowLength;
+ private final long windowLengthInMs;
/**
* Start time of the window in milliseconds.
@@ -40,18 +40,18 @@ public class WindowWrap {
private T value;
/**
- * @param windowLength the time length of the window
+ * @param windowLengthInMs a single window bucket's time length in milliseconds.
* @param windowStart the start timestamp of the window
* @param value window data
*/
- public WindowWrap(long windowLength, long windowStart, T value) {
- this.windowLength = windowLength;
+ public WindowWrap(long windowLengthInMs, long windowStart, T value) {
+ this.windowLengthInMs = windowLengthInMs;
this.windowStart = windowStart;
this.value = value;
}
public long windowLength() {
- return windowLength;
+ return windowLengthInMs;
}
public long windowStart() {
@@ -74,7 +74,7 @@ public class WindowWrap {
@Override
public String toString() {
return "WindowWrap{" +
- "windowLength=" + windowLength +
+ "windowLengthInMs=" + windowLengthInMs +
", windowStart=" + windowStart +
", value=" + value +
'}';
diff --git a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/metric/ArrayMetric.java b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/metric/ArrayMetric.java
index b7df1efa..684c8365 100755
--- a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/metric/ArrayMetric.java
+++ b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/metric/ArrayMetric.java
@@ -33,8 +33,14 @@ public class ArrayMetric implements Metric {
private final MetricsLeapArray data;
- public ArrayMetric(int windowLength, int interval) {
- this.data = new MetricsLeapArray(windowLength, interval);
+ /**
+ * Constructor
+ *
+ * @param windowLengthInMs a single window bucket's time length in milliseconds.
+ * @param intervalInSec the total time span of this {@link ArrayMetric} in seconds.
+ */
+ public ArrayMetric(int windowLengthInMs, int intervalInSec) {
+ this.data = new MetricsLeapArray(windowLengthInMs, intervalInSec);
}
/**
diff --git a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/metric/MetricsLeapArray.java b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/metric/MetricsLeapArray.java
index 0c2dcb86..d5972b6d 100755
--- a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/metric/MetricsLeapArray.java
+++ b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/metric/MetricsLeapArray.java
@@ -22,11 +22,18 @@ import com.alibaba.csp.sentinel.slots.statistic.base.WindowWrap;
/**
* The fundamental data structure for metric statistics in a time window.
*
+ * @see LeapArray
* @author jialiang.linjl
* @author Eric Zhao
*/
public class MetricsLeapArray extends LeapArray {
+ /**
+ * Constructor
+ *
+ * @param windowLengthInMs a single window bucket's time length in milliseconds.
+ * @param intervalInSec the total time span of this {@link MetricsLeapArray} in seconds.
+ */
public MetricsLeapArray(int windowLengthInMs, int intervalInSec) {
super(windowLengthInMs, intervalInSec);
}