diff --git a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/MetricEvent.java b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/MetricEvent.java new file mode 100644 index 00000000..f05dc966 --- /dev/null +++ b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/MetricEvent.java @@ -0,0 +1,37 @@ +/* + * Copyright 1999-2018 Alibaba Group Holding Ltd. + * + * Licensed 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 com.alibaba.csp.sentinel.slots.statistic; + +/** + * @author Eric Zhao + */ +public enum MetricEvent { + + /** + * Normal pass. + */ + PASS, + /** + * Normal block. + */ + BLOCK, + EXCEPTION, + SUCCESS, + RT, + OCCUPIED_PASS, + OCCUPIED_BLOCK, + WAITING +} 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 51aae33d..38061dc3 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 @@ -25,12 +25,12 @@ import com.alibaba.csp.sentinel.util.TimeUtil; /** *

- * Basic data structure for statistic metrics. + * Basic data structure for statistic metrics in Sentinel. *

*

- * 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. + * Leap array use sliding window algorithm to count data. Each bucket cover {code windowLengthInMs} time span, + * and the total time span is {@link #intervalInMs}, so the total bucket amount is: + * {@code sampleCount = intervalInMs / windowLengthInMs}. *

* * @param type of statistic data @@ -47,7 +47,7 @@ public abstract class LeapArray { protected final AtomicReferenceArray> array; /** - * The fine-grained update lock is used only when current bucket is deprecated. + * The conditional (predicate) update lock is used only when current bucket is deprecated. */ private final ReentrantLock updateLock = new ReentrantLock(); @@ -58,9 +58,10 @@ public abstract class LeapArray { * @param intervalInSec the total time span of this {@link LeapArray} in seconds. */ public LeapArray(int windowLengthInMs, int intervalInSec) { + // TODO: change `intervalInSec` to `intervalInMs` AssertUtil.isTrue(windowLengthInMs > 0, "bucket length is invalid: " + windowLengthInMs); int intervalInMs = intervalInSec * 1000; - AssertUtil.isTrue(intervalInSec * 1000 > windowLengthInMs, + AssertUtil.isTrue(intervalInMs > windowLengthInMs, "total time span of the window should be greater than bucket length"); AssertUtil.isTrue(intervalInMs % windowLengthInMs == 0, "time span needs to be evenly divided"); @@ -90,28 +91,36 @@ public abstract class LeapArray { /** * Reset given bucket to provided start time and reset the value. * - * @param startTime the start time of the bucket + * @param startTime the start time of the bucket in milliseconds * @param windowWrap current bucket * @return new clean bucket at given start time */ protected abstract WindowWrap resetWindowTo(WindowWrap windowWrap, long startTime); + protected int calculateTimeIdx(/*@Valid*/ long timeMillis) { + long timeId = timeMillis / windowLengthInMs; + // Calculate current index so we can map the timestamp to the leap array. + return (int)(timeId % array.length()); + } + + protected long calculateWindowStart(/*@Valid*/ long timeMillis) { + return timeMillis - timeMillis % windowLengthInMs; + } + /** * Get bucket item at provided timestamp. * - * @param time a valid timestamp + * @param timeMillis a valid timestamp in milliseconds * @return current bucket item at provided timestamp if the time is valid; null if time is invalid */ - public WindowWrap currentWindow(long time) { - if (time < 0) { + public WindowWrap currentWindow(long timeMillis) { + if (timeMillis < 0) { return null; } - long timeId = time / windowLengthInMs; - // Calculate current index so we can map the timestamp to the leap array. - int idx = (int)(timeId % array.length()); + int idx = calculateTimeIdx(timeMillis); // Calculate current bucket start time. - long windowStart = time - time % windowLengthInMs; + long windowStart = calculateWindowStart(timeMillis); /* * Get bucket item at given time from the array. @@ -171,7 +180,7 @@ public abstract class LeapArray { * Note that the reset and clean-up operations are hard to be atomic, * so we need a update lock to guarantee the correctness of bucket update. * - * The update lock is fine-grained and will take effect only when + * The update lock is conditional (tiny scope) and will take effect only when * bucket is deprecated, so in most cases it won't lead to performance loss. */ if (updateLock.tryLock()) { @@ -195,23 +204,23 @@ public abstract class LeapArray { /** * Get the previous bucket item before provided timestamp. * - * @param time a valid timestamp + * @param timeMillis a valid timestamp in milliseconds * @return the previous bucket item before provided timestamp */ - public WindowWrap getPreviousWindow(long time) { - if (time < 0) { + public WindowWrap getPreviousWindow(long timeMillis) { + if (timeMillis < 0) { return null; } - long timeId = (time - windowLengthInMs) / windowLengthInMs; - int idx = (int)(timeId % array.length()); - time = time - windowLengthInMs; + int idx = calculateTimeIdx(timeMillis); + + long previousTime = timeMillis - windowLengthInMs; WindowWrap wrap = array.get(idx); if (wrap == null || isWindowDeprecated(wrap)) { return null; } - if (wrap.windowStart() + windowLengthInMs < (time)) { + if (wrap.windowStart() + windowLengthInMs < previousTime) { return null; } @@ -230,15 +239,14 @@ public abstract class LeapArray { /** * Get statistic value from bucket for provided timestamp. * - * @param time a valid timestamp + * @param time a valid timestamp in milliseconds * @return the statistic value if bucket for provided timestamp is up-to-date; otherwise null */ public T getWindowValue(long time) { if (time < 0) { return null; } - long timeId = time / windowLengthInMs; - int idx = (int)(timeId % array.length()); + int idx = calculateTimeIdx(time); WindowWrap old = array.get(idx); if (old == null || isWindowDeprecated(old)) { @@ -255,7 +263,7 @@ public abstract class LeapArray { * @param windowWrap a non-null bucket * @return true if the bucket is deprecated; otherwise false */ - private boolean isWindowDeprecated(/*@NonNull*/ WindowWrap windowWrap) { + protected boolean isWindowDeprecated(/*@NonNull*/ WindowWrap windowWrap) { return TimeUtil.currentTimeMillis() - windowWrap.windowStart() >= intervalInMs; } @@ -266,9 +274,10 @@ public abstract class LeapArray { * @return valid bucket list for entire sliding window. */ public List> list() { - List> result = new ArrayList>(); + int size = array.length(); + List> result = new ArrayList>(size); - for (int i = 0; i < array.length(); i++) { + for (int i = 0; i < size; i++) { WindowWrap windowWrap = array.get(i); if (windowWrap == null || isWindowDeprecated(windowWrap)) { continue; @@ -286,9 +295,10 @@ public abstract class LeapArray { * @return aggregated value list for entire sliding window */ public List values() { - List result = new ArrayList(); + int size = array.length(); + List result = new ArrayList(size); - for (int i = 0; i < array.length(); i++) { + for (int i = 0; i < size; i++) { WindowWrap windowWrap = array.get(i); if (windowWrap == null || isWindowDeprecated(windowWrap)) { continue; @@ -298,6 +308,34 @@ public abstract class LeapArray { return result; } + /** + * Get the valid "head" bucket of the sliding window for provided timestamp. + * Package-private for test. + * + * @param timeMillis a valid timestamp in milliseconds + * @return the "head" bucket if it exists and is valid; otherwise null + */ + WindowWrap getValidHead(long timeMillis) { + // Calculate index for expected head time. + int idx = calculateTimeIdx(timeMillis + windowLengthInMs); + + WindowWrap wrap = array.get(idx); + if (wrap == null || isWindowDeprecated(wrap)) { + return null; + } + + return wrap; + } + + /** + * Get the valid "head" bucket of the sliding window at current timestamp. + * + * @return the "head" bucket if it exists and is valid; otherwise null + */ + public WindowWrap getValidHead() { + return getValidHead(TimeUtil.currentTimeMillis()); + } + /** * Get sample count (total amount of buckets). * diff --git a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/base/MetricBucket.java b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/data/MetricBucket.java similarity index 95% rename from sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/base/MetricBucket.java rename to sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/data/MetricBucket.java index d59ca984..0e96a28c 100755 --- a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/base/MetricBucket.java +++ b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/data/MetricBucket.java @@ -13,9 +13,10 @@ * See the License for the specific language governing permissions and * limitations under the License. */ -package com.alibaba.csp.sentinel.slots.statistic.base; +package com.alibaba.csp.sentinel.slots.statistic.data; import com.alibaba.csp.sentinel.Constants; +import com.alibaba.csp.sentinel.slots.statistic.base.LongAdder; /** * Represents metrics data in a period of time span. 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 7a141a54..e0c75418 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 @@ -20,7 +20,7 @@ import java.util.List; import com.alibaba.csp.sentinel.Constants; import com.alibaba.csp.sentinel.node.metric.MetricNode; -import com.alibaba.csp.sentinel.slots.statistic.base.MetricBucket; +import com.alibaba.csp.sentinel.slots.statistic.data.MetricBucket; import com.alibaba.csp.sentinel.slots.statistic.base.WindowWrap; /** diff --git a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/metric/Metric.java b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/metric/Metric.java index 1b62057a..954614a3 100755 --- a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/metric/Metric.java +++ b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/statistic/metric/Metric.java @@ -18,7 +18,7 @@ package com.alibaba.csp.sentinel.slots.statistic.metric; import java.util.List; import com.alibaba.csp.sentinel.node.metric.MetricNode; -import com.alibaba.csp.sentinel.slots.statistic.base.MetricBucket; +import com.alibaba.csp.sentinel.slots.statistic.data.MetricBucket; /** * Represents a basic structure recording invocation metrics of protected resources. 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 fcf452e1..2a1cda4b 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 @@ -16,7 +16,7 @@ package com.alibaba.csp.sentinel.slots.statistic.metric; import com.alibaba.csp.sentinel.slots.statistic.base.LeapArray; -import com.alibaba.csp.sentinel.slots.statistic.base.MetricBucket; +import com.alibaba.csp.sentinel.slots.statistic.data.MetricBucket; import com.alibaba.csp.sentinel.slots.statistic.base.WindowWrap; /** diff --git a/sentinel-core/src/test/java/com/alibaba/csp/sentinel/base/metric/ArrayMetricTest.java b/sentinel-core/src/test/java/com/alibaba/csp/sentinel/base/metric/ArrayMetricTest.java index 02e33732..6df540cd 100755 --- a/sentinel-core/src/test/java/com/alibaba/csp/sentinel/base/metric/ArrayMetricTest.java +++ b/sentinel-core/src/test/java/com/alibaba/csp/sentinel/base/metric/ArrayMetricTest.java @@ -19,7 +19,7 @@ import java.util.ArrayList; import org.junit.Test; -import com.alibaba.csp.sentinel.slots.statistic.base.MetricBucket; +import com.alibaba.csp.sentinel.slots.statistic.data.MetricBucket; import com.alibaba.csp.sentinel.slots.statistic.base.WindowWrap; import com.alibaba.csp.sentinel.slots.statistic.metric.ArrayMetric; import com.alibaba.csp.sentinel.slots.statistic.metric.MetricsLeapArray; diff --git a/sentinel-core/src/test/java/com/alibaba/csp/sentinel/base/metric/MetricsLeapArrayTest.java b/sentinel-core/src/test/java/com/alibaba/csp/sentinel/base/metric/MetricsLeapArrayTest.java index 735838e4..8998895c 100755 --- a/sentinel-core/src/test/java/com/alibaba/csp/sentinel/base/metric/MetricsLeapArrayTest.java +++ b/sentinel-core/src/test/java/com/alibaba/csp/sentinel/base/metric/MetricsLeapArrayTest.java @@ -21,7 +21,7 @@ import java.util.List; import java.util.Set; import java.util.concurrent.CountDownLatch; -import com.alibaba.csp.sentinel.slots.statistic.base.MetricBucket; +import com.alibaba.csp.sentinel.slots.statistic.data.MetricBucket; import com.alibaba.csp.sentinel.util.TimeUtil; import com.alibaba.csp.sentinel.slots.statistic.base.WindowWrap; import com.alibaba.csp.sentinel.slots.statistic.metric.MetricsLeapArray; diff --git a/sentinel-core/src/test/java/com/alibaba/csp/sentinel/slots/statistic/base/LeapArrayTest.java b/sentinel-core/src/test/java/com/alibaba/csp/sentinel/slots/statistic/base/LeapArrayTest.java new file mode 100644 index 00000000..e5ccbda2 --- /dev/null +++ b/sentinel-core/src/test/java/com/alibaba/csp/sentinel/slots/statistic/base/LeapArrayTest.java @@ -0,0 +1,69 @@ +/* + * Copyright 1999-2018 Alibaba Group Holding Ltd. + * + * Licensed 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 com.alibaba.csp.sentinel.slots.statistic.base; + +import java.util.concurrent.atomic.AtomicInteger; + +import org.junit.Test; + +import static org.junit.Assert.*; + +/** + * @author Eric Zhao + */ +public class LeapArrayTest { + + @Test + public void testGetValidHead() { + int windowLengthInMs = 100; + int intervalInSec = 1; + int sampleCount = intervalInSec * 1000 / windowLengthInMs; + LeapArray leapArray = new LeapArray(windowLengthInMs, intervalInSec) { + @Override + public AtomicInteger newEmptyBucket() { + return new AtomicInteger(0); + } + + @Override + protected WindowWrap resetWindowTo(WindowWrap windowWrap, long startTime) { + windowWrap.resetTo(startTime); + windowWrap.value().set(0); + return windowWrap; + } + }; + WindowWrap expected1 = leapArray.currentWindow(); + expected1.value().addAndGet(1); + sleep(windowLengthInMs); + WindowWrap expected2 = leapArray.currentWindow(); + expected2.value().addAndGet(2); + for (int i = 0; i < sampleCount - 2; i++) { + sleep(windowLengthInMs); + leapArray.currentWindow().value().addAndGet(i + 3); + } + + assertSame(expected1, leapArray.getValidHead()); + sleep(windowLengthInMs); + assertSame(expected2, leapArray.getValidHead()); + } + + private void sleep(int t) { + try { + Thread.sleep(t); + } catch (InterruptedException e) { + e.printStackTrace(); + } + } +} \ No newline at end of file