Circuit breaker

src/main/java/com/amazon/opendistroforelasticsearch/ad/breaker/ADCircuitBreakerService.java

@@ -77,4 +77,14 @@ public ADCircuitBreakerService init() {
 
         return this;
     }
+
+    public Boolean isOpen() {
+        for (CircuitBreaker breaker : breakers.values()) {
+            if (breaker.isOpen()) {
+                return true;
+            }
+        }
+
+        return false;
+    }
 }

src/main/java/com/amazon/opendistroforelasticsearch/ad/constant/CommonErrorMessages.java

@@ -23,4 +23,5 @@ public class CommonErrorMessages {
     public static final String NO_CHECKPOINT_ERR_MSG = "No checkpoints found for model id ";
     public static final String MEMORY_LIMIT_EXCEEDED_ERR_MSG = "AD models memory usage exceeds our limit.";
     public static final String FEATURE_NOT_AVAILABLE_ERR_MSG = "No Feature in current detection window.";
+    public static final String MEMORY_CIRCUIT_BROKEN_ERR_MSG = "AD memory circuit is broken.";
 }

src/main/java/com/amazon/opendistroforelasticsearch/ad/transport/AnomalyResultTransportAction.java

@@ -28,6 +28,7 @@
 import java.util.concurrent.atomic.AtomicReference;
 import java.time.Instant;
 
+import com.amazon.opendistroforelasticsearch.ad.breaker.ADCircuitBreakerService;
 import com.amazon.opendistroforelasticsearch.ad.cluster.HashRing;
 import com.amazon.opendistroforelasticsearch.ad.common.exception.AnomalyDetectionException;
 import com.amazon.opendistroforelasticsearch.ad.common.exception.ClientException;
@@ -120,13 +121,14 @@ public class AnomalyResultTransportAction extends HandledTransportAction<ActionR
     private final IndexNameExpressionResolver indexNameExpressionResolver;
     private final ThreadPool threadPool;
     private final BackoffPolicy resultSavingBackoffPolicy;
+    private final ADCircuitBreakerService adCircuitBreakerService;
 
     @Inject
     public AnomalyResultTransportAction(ActionFilters actionFilters, TransportService transportService, Client client,
             Settings settings, ADStateManager manager, ColdStartRunner eventExecutor,
             AnomalyDetectionIndices anomalyDetectionIndices, FeatureManager featureManager, ModelManager modelManager,
             HashRing hashRing, ClusterService clusterService, IndexNameExpressionResolver indexNameExpressionResolver,
-            ThreadPool threadPool) {
+            ThreadPool threadPool, ADCircuitBreakerService adCircuitBreakerService) {
         super(AnomalyResultAction.NAME, transportService, actionFilters, AnomalyResultRequest::new);
         this.transportService = transportService;
         this.client = client;
@@ -145,6 +147,7 @@ public AnomalyResultTransportAction(ActionFilters actionFilters, TransportServic
         this.threadPool = threadPool;
         this.resultSavingBackoffPolicy = BackoffPolicy.exponentialBackoff(AnomalyDetectorSettings.BACKOFF_INITIAL_DELAY.get(settings),
                 AnomalyDetectorSettings.MAX_RETRY_FOR_BACKOFF.get(settings));
+        this.adCircuitBreakerService = adCircuitBreakerService;
     }
 
     private List<FeatureData> getFeatureData(double[] currentFeature, AnomalyDetector detector) {
@@ -207,6 +210,11 @@ protected void doExecute(Task task, ActionRequest actionRequest, ActionListener<
         AnomalyResultRequest request = AnomalyResultRequest.fromActionRequest(actionRequest);
         String adID = request.getAdID();
 
+        if (adCircuitBreakerService.isOpen()) {
+            listener.onFailure(new LimitExceededException(adID, CommonErrorMessages.MEMORY_CIRCUIT_BROKEN_ERR_MSG));
+            return;
+        }
+
         try {
             Optional<AnomalyDetector> detector = stateManager.getAnomalyDetector(adID);
             if (!detector.isPresent()) {

src/main/java/com/amazon/opendistroforelasticsearch/ad/transport/RCFResultTransportAction.java

@@ -15,6 +15,9 @@
 
 package com.amazon.opendistroforelasticsearch.ad.transport;
 
+import com.amazon.opendistroforelasticsearch.ad.breaker.ADCircuitBreakerService;
+import com.amazon.opendistroforelasticsearch.ad.common.exception.LimitExceededException;
+import com.amazon.opendistroforelasticsearch.ad.constant.CommonErrorMessages;
 import com.amazon.opendistroforelasticsearch.ad.ml.ModelManager;
 import com.amazon.opendistroforelasticsearch.ad.ml.RcfResult;
 import org.apache.logging.log4j.LogManager;
@@ -30,17 +33,24 @@ public class RCFResultTransportAction extends HandledTransportAction<RCFResultRe
 
     private static final Logger LOG = LogManager.getLogger(RCFResultTransportAction.class);
     private ModelManager manager;
+    private ADCircuitBreakerService adCircuitBreakerService;
 
     @Inject
     public RCFResultTransportAction(ActionFilters actionFilters, TransportService transportService,
-            ModelManager manager) {
+            ModelManager manager, ADCircuitBreakerService adCircuitBreakerService) {
         super(RCFResultAction.NAME, transportService, actionFilters, RCFResultRequest::new);
         this.manager = manager;
+        this.adCircuitBreakerService = adCircuitBreakerService;
     }
 
     @Override
     protected void doExecute(Task task, RCFResultRequest request, ActionListener<RCFResultResponse> listener) {
 
+        if (adCircuitBreakerService.isOpen()) {
+            listener.onFailure(new LimitExceededException(request.getAdID(), CommonErrorMessages.MEMORY_CIRCUIT_BROKEN_ERR_MSG));
+            return;
+        }
+
         try {
             LOG.info("Serve rcf request for {}", request.getModelID());
             RcfResult result = manager.getRcfResult(request.getAdID(), request.getModelID(), request.getFeatures());

src/test/java/com/amazon/opendistroforelasticsearch/ad/breaker/ADCircuitBreakerServiceTests.java

@@ -16,16 +16,19 @@
 package com.amazon.opendistroforelasticsearch.ad.breaker;
 
 import org.elasticsearch.monitor.jvm.JvmService;
+import org.elasticsearch.monitor.jvm.JvmStats;
 import org.junit.Before;
 import org.junit.Test;
 import org.mockito.InjectMocks;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 
 import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.notNullValue;
 import static org.hamcrest.Matchers.nullValue;
+import static org.mockito.Mockito.when;
 
 public class ADCircuitBreakerServiceTests {
 
@@ -35,6 +38,12 @@ public class ADCircuitBreakerServiceTests {
     @Mock
     JvmService jvmService;
 
+    @Mock
+    JvmStats jvmStats;
+
+    @Mock
+    JvmStats.Mem mem;
+
     @Before
     public void setup() {
         MockitoAnnotations.initMocks(this);
@@ -88,4 +97,23 @@ public void testInit() {
         assertThat(adCircuitBreakerService.init(), is(notNullValue()));
     }
 
+    @Test
+    public void testIsOpen() {
+        when(jvmService.stats()).thenReturn(jvmStats);
+        when(jvmStats.getMem()).thenReturn(mem);
+        when(mem.getHeapUsedPercent()).thenReturn((short)50);
+
+        adCircuitBreakerService.registerBreaker(BreakerName.MEM.getName(), new MemoryCircuitBreaker(jvmService));
+        assertThat(adCircuitBreakerService.isOpen(), equalTo(false));
+    }
+
+    @Test
+    public void testIsOpen1() {
+        when(jvmService.stats()).thenReturn(jvmStats);
+        when(jvmStats.getMem()).thenReturn(mem);
+        when(mem.getHeapUsedPercent()).thenReturn((short)90);
+
+        adCircuitBreakerService.registerBreaker(BreakerName.MEM.getName(), new MemoryCircuitBreaker(jvmService));
+        assertThat(adCircuitBreakerService.isOpen(), equalTo(true));
+    }
 }