Update demo for circuit breaking (DegradeRule)

Signed-off-by: Eric Zhao <sczyh16@gmail.com>
alibaba · Jul 30, 2020 · 19db20f · 19db20f
1 parent 07b8111
commit 19db20f
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diff --git a/...-basic/src/main/java/com/alibaba/csp/sentinel/demo/degrade/ExceptionCountDegradeDemo.java b/...-basic/src/main/java/com/alibaba/csp/sentinel/demo/degrade/ExceptionCountDegradeDemo.java
diff --git a/...mo/degrade/ExceptionRatioDegradeDemo.java → ...ade/ExceptionRatioCircuitBreakerDemo.java b/...mo/degrade/ExceptionRatioDegradeDemo.java → ...ade/ExceptionRatioCircuitBreakerDemo.java
@@ -19,127 +19,131 @@
 import com.alibaba.csp.sentinel.SphU;
 import com.alibaba.csp.sentinel.Tracer;
 import com.alibaba.csp.sentinel.slots.block.BlockException;
-import com.alibaba.csp.sentinel.slots.block.RuleConstant;
 import com.alibaba.csp.sentinel.slots.block.degrade.DegradeRule;
 import com.alibaba.csp.sentinel.slots.block.degrade.DegradeRuleManager;
+import com.alibaba.csp.sentinel.slots.block.degrade.circuitbreaker.CircuitBreaker.State;
+import com.alibaba.csp.sentinel.slots.block.degrade.circuitbreaker.CircuitBreakerStrategy;
+import com.alibaba.csp.sentinel.slots.block.degrade.circuitbreaker.EventObserverRegistry;
 import com.alibaba.csp.sentinel.util.TimeUtil;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.ThreadLocalRandom;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 
 /**
- * <p>
- * Degrade is used when the resources are in an unstable state, these resources
- * will be degraded within the next defined time window. There are three ways to
- * measure whether a resource is stable or not:
- * <ul>
- * <li>
- * Exception ratio: When the ratio of exception count per second and the success
- * qps greats than or equals to the threshold, access to the resource will be blocked
- * in the coming time window.
- * </li>
- * <li>
- * Exception Count, see {@link ExceptionCountDegradeDemo}.
- * </li>
- * <li>
- * For average response time, see {@link RtDegradeDemo}.
- * </li>
- * </ul>
- * </p>
- *
  * @author jialiang.linjl
+ * @author Eric Zhao
  */
-public class ExceptionRatioDegradeDemo {
+public class ExceptionRatioCircuitBreakerDemo {
 
-    private static final String KEY = "abc";
+    private static final String KEY = "some_service";
 
     private static AtomicInteger total = new AtomicInteger();
     private static AtomicInteger pass = new AtomicInteger();
     private static AtomicInteger block = new AtomicInteger();
     private static AtomicInteger bizException = new AtomicInteger();
 
     private static volatile boolean stop = false;
-    private static final int threadCount = 1;
-    private static int seconds = 60 + 40;
+    private static int seconds = 120;
 
     public static void main(String[] args) throws Exception {
-        tick();
         initDegradeRule();
-
-        for (int i = 0; i < threadCount; i++) {
-            Thread entryThread = new Thread(new Runnable() {
-
-                @Override
-                public void run() {
-                    int count = 0;
-                    while (true) {
-                        count++;
-                        Entry entry = null;
-                        try {
-                            Thread.sleep(20);
-                            entry = SphU.entry(KEY);
-                            // token acquired, means pass
-                            pass.addAndGet(1);
-                            if (count % 2 == 0) {
-                                // biz code raise an exception.
-                                throw new RuntimeException("throw runtime ");
-                            }
-                        } catch (BlockException e) {
-                            block.addAndGet(1);
-                        } catch (Throwable t) {
-                            bizException.incrementAndGet();
-                            Tracer.trace(t);
-                        } finally {
-                            total.addAndGet(1);
-                            if (entry != null) {
-                                entry.exit();
-                            }
+        registerStateChangeObserver();
+        startTick();
+
+        final int concurrency = 8;
+        for (int i = 0; i < concurrency; i++) {
+            Thread entryThread = new Thread(() -> {
+                while (true) {
+                    Entry entry = null;
+                    try {
+                        entry = SphU.entry(KEY);
+                        sleep(ThreadLocalRandom.current().nextInt(5, 10));
+                        pass.addAndGet(1);
+
+                        // Error probability is 45%
+                        if (ThreadLocalRandom.current().nextInt(0, 100) > 55) {
+                            // biz code raise an exception.
+                            throw new RuntimeException("oops");
+                        }
+                    } catch (BlockException e) {
+                        block.addAndGet(1);
+                        sleep(ThreadLocalRandom.current().nextInt(5, 10));
+                    } catch (Throwable t) {
+                        bizException.incrementAndGet();
+                        // It's required to record exception here manually.
+                        Tracer.traceEntry(t, entry);
+                    } finally {
+                        total.addAndGet(1);
+                        if (entry != null) {
+                            entry.exit();
                         }
                     }
                 }
-
             });
-            entryThread.setName("working-thread");
+            entryThread.setName("sentinel-simulate-traffic-task-" + i);
             entryThread.start();
         }
+    }
 
+    private static void registerStateChangeObserver() {
+        EventObserverRegistry.getInstance().addStateChangeObserver("logging",
+            (prevState, newState, rule, snapshotValue) -> {
+                if (newState == State.OPEN) {
+                    System.err.println(String.format("%s -> OPEN at %d, snapshotValue=%.2f", prevState.name(),
+                        TimeUtil.currentTimeMillis(), snapshotValue));
+                } else {
+                    System.err.println(String.format("%s -> %s at %d", prevState.name(), newState.name(),
+                        TimeUtil.currentTimeMillis()));
+                }
+            });
     }
 
     private static void initDegradeRule() {
-        List<DegradeRule> rules = new ArrayList<DegradeRule>();
-        DegradeRule rule = new DegradeRule();
-        rule.setResource(KEY);
-        // set limit exception ratio to 0.1
-        rule.setCount(0.1);
-        rule.setGrade(RuleConstant.DEGRADE_GRADE_EXCEPTION_RATIO);
-        rule.setTimeWindow(10);
-        rule.setMinRequestAmount(20);
+        List<DegradeRule> rules = new ArrayList<>();
+        DegradeRule rule = new DegradeRule(KEY)
+            .setGrade(CircuitBreakerStrategy.ERROR_RATIO.getType())
+            // Set ratio threshold to 50%.
+            .setCount(0.5d)
+            .setStatIntervalMs(30000)
+            .setMinRequestAmount(50)
+            // Retry timeout (in second)
+            .setTimeWindow(10);
         rules.add(rule);
         DegradeRuleManager.loadRules(rules);
+        System.out.println("Degrade rule loaded: " + rules);
     }
 
-    private static void tick() {
+    private static void sleep(int timeMs) {
+        try {
+            TimeUnit.MILLISECONDS.sleep(timeMs);
+        } catch (InterruptedException e) {
+            // ignore
+        }
+    }
+
+    private static void startTick() {
         Thread timer = new Thread(new TimerTask());
-        timer.setName("sentinel-timer-task");
+        timer.setName("sentinel-timer-tick-task");
         timer.start();
     }
 
     static class TimerTask implements Runnable {
         @Override
         public void run() {
             long start = System.currentTimeMillis();
-            System.out.println("begin to statistic!!!");
+            System.out.println("Begin to run! Go go go!");
+            System.out.println("See corresponding metrics.log for accurate statistic data");
+
             long oldTotal = 0;
             long oldPass = 0;
             long oldBlock = 0;
             long oldBizException = 0;
             while (!stop) {
-                try {
-                    TimeUnit.SECONDS.sleep(1);
-                } catch (InterruptedException e) {
-                }
+                sleep(1000);
+
                 long globalTotal = total.get();
                 long oneSecondTotal = globalTotal - oldTotal;
                 oldTotal = globalTotal;
@@ -166,7 +170,7 @@ public void run() {
             }
             long cost = System.currentTimeMillis() - start;
             System.out.println("time cost: " + cost + " ms");
-            System.out.println("total:" + total.get() + ", pass:" + pass.get()
+            System.out.println("total: " + total.get() + ", pass:" + pass.get()
                 + ", block:" + block.get() + ", bizException:" + bizException.get());
             System.exit(0);
         }