Add exceptionsToIgnore configuration support in @SentinelResource annotation (#683)

sentinel-core/src/main/java/com/alibaba/csp/sentinel/annotation/SentinelResource.java

@@ -65,4 +65,14 @@ public @interface SentinelResource {
      * @since 1.5.1
      */
     Class<? extends Throwable>[] exceptionsToTrace() default {Throwable.class};
+    
+    /**
+     * Indicates the exceptions to be ignored. Note that {@code exceptionsToTrace} should
+     * not appear with {@code exceptionsToIgnore} at the same time, or {@code exceptionsToIgnore}
+     * will be of higher precedence.
+     *
+     * @return the list of exception classes to ignore, empty by default
+     * @since 1.6.0
+     */
+    Class<? extends Throwable>[] exceptionsToIgnore() default {};
 }

sentinel-extension/sentinel-annotation-aspectj/src/main/java/com/alibaba/csp/sentinel/annotation/aspectj/AbstractSentinelAspectSupport.java

@@ -78,6 +78,11 @@ public abstract class AbstractSentinelAspectSupport {
     }
 
     protected void traceException(Throwable ex, SentinelResource annotation) {
+        Class<? extends Throwable>[] exceptionsToIgnore = annotation.exceptionsToIgnore();
+        // The ignore list will be checked first.
+        if (exceptionsToIgnore.length > 0 && isIgnoredException(ex, exceptionsToIgnore)) {
+            return;
+        }
         if (isTracedException(ex, annotation.exceptionsToTrace())) {
             Tracer.trace(ex);
         }
@@ -86,8 +91,10 @@ public abstract class AbstractSentinelAspectSupport {
     /**
      * Check whether the exception is in tracked list of exception classes.
      *
-     * @param ex provided throwable
-     * @param exceptionsToTrace list of exceptions to trace
+     * @param ex
+     *            provided throwable
+     * @param exceptionsToTrace
+     *            list of exceptions to trace
      * @return true if it should be traced, otherwise false
      */
     private boolean isTracedException(Throwable ex, Class<? extends Throwable>[] exceptionsToTrace) {
@@ -102,6 +109,18 @@ public abstract class AbstractSentinelAspectSupport {
         return false;
     }
 
+    private boolean isIgnoredException(Throwable ex, Class<? extends Throwable>[] exceptionsToIgnore) {
+        if (exceptionsToIgnore == null) {
+            return false;
+        }
+        for (Class<? extends Throwable> exceptionToIgnore : exceptionsToIgnore) {
+            if (exceptionToIgnore.isAssignableFrom(ex.getClass())) {
+                return true;
+            }
+        }
+        return false;
+    }
+
     private boolean isDegradeFailure(/*@NonNull*/ BlockException ex) {
         return ex instanceof DegradeException;
     }

sentinel-extension/sentinel-annotation-aspectj/src/test/java/com/alibaba/csp/sentinel/annotation/aspectj/integration/SentinelAnnotationIntegrationTest.java

@@ -83,6 +83,22 @@ public class SentinelAnnotationIntegrationTest extends AbstractJUnit4SpringConte
         fooService.baz("Sentinel");
     }
 
+    @Test
+    public void testAnnotationExceptionsToIgnore() {
+        assertThat(fooService.baz("Sentinel")).isEqualTo("cheers, Sentinel");
+        String resourceName = "apiBaz";
+        ClusterNode cn = ClusterBuilderSlot.getClusterNode(resourceName);
+        assertThat(cn).isNotNull();
+        assertThat(cn.passQps()).isPositive();
+
+        try {
+            fooService.baz("fail");
+            fail("should not reach here");
+        } catch (IllegalMonitorStateException ex) {
+            assertThat(cn.exceptionQps()).isZero();
+        }
+    }
+
     @Test
     public void testNormalBlockHandlerAndFallback() throws Exception {
         assertThat(fooService.foo(1)).isEqualTo("Hello for 1");

sentinel-extension/sentinel-annotation-aspectj/src/test/java/com/alibaba/csp/sentinel/annotation/aspectj/integration/service/FooService.java

@@ -49,8 +49,12 @@ public class FooService {
         return ThreadLocalRandom.current().nextInt(0, 30000);
     }
 
-    @SentinelResource(value = "apiBaz", blockHandler = "bazBlockHandler")
+    @SentinelResource(value = "apiBaz", blockHandler = "bazBlockHandler",
+            exceptionsToIgnore = {IllegalMonitorStateException.class})
     public String baz(String name) {
+        if (name.equals("fail")) {
+            throw new IllegalMonitorStateException("boom!");
+        }
         return "cheers, " + name;
     }