Examples with DegraderControl com.linkedin.util.degrader.DegraderControl used on opensource projects

Example 1 with DegraderControl

use of com.linkedin.util.degrader.DegraderControl in project rest.li by linkedin.

the class DegraderLoadBalancerStrategyV3 method overrideMinCallCount.

/**
   * Both the drop in hash ring points and the global drop rate influence the minimum call count
   * that we should see to qualify for a state update. Currently, both factors are equally weighed,
   * and multiplied together to come up with a scale factor. With this scheme, if either factor is
   * zero, then the overrideMinCallCount will be set to 1. If both factors are at half weight, then
   * the overall weight will be .5 * .5 = .25 of the original minCallCount.
   *
   * @param newOverrideDropRate
   * @param trackerClientUpdaters
   * @param pointsMap
   * @param pointsPerWeight
   */
public static void overrideMinCallCount(int partitionId, double newOverrideDropRate, List<TrackerClientUpdater> trackerClientUpdaters, Map<URI, Integer> pointsMap, int pointsPerWeight) {
    for (TrackerClientUpdater clientUpdater : trackerClientUpdaters) {
        TrackerClient client = clientUpdater.getTrackerClient();
        DegraderControl degraderControl = client.getDegraderControl(partitionId);
        int currentOverrideMinCallCount = client.getDegraderControl(partitionId).getOverrideMinCallCount();
        double hashFactor = pointsMap.get(client.getUri()) / pointsPerWeight;
        double transmitFactor = 1.0 - newOverrideDropRate;
        int newOverrideMinCallCount = (int) Math.max(Math.round(degraderControl.getMinCallCount() * hashFactor * transmitFactor), 1);
        if (newOverrideMinCallCount != currentOverrideMinCallCount) {
            clientUpdater.setOverrideMinCallCount(newOverrideMinCallCount);
            // log min call count change if current value != initial value
            if (currentOverrideMinCallCount != DegraderImpl.DEFAULT_OVERRIDE_MIN_CALL_COUNT) {
                warn(_log, "partitionId=", partitionId, "overriding Min Call Count to ", newOverrideMinCallCount, " for client: ", client.getUri());
            }
        }
    }
}

Example 2 with DegraderControl

use of com.linkedin.util.degrader.DegraderControl in project rest.li by linkedin.

the class TrackerClientTest method testCallTrackingRestRequest.

@Test
public void testCallTrackingRestRequest() throws Exception {
    URI uri = URI.create("http://test.qa.com:1234/foo");
    SettableClock clock = new SettableClock();
    AtomicInteger action = new AtomicInteger(0);
    TransportClient tc = new TransportClient() {

        @Override
        public void restRequest(RestRequest request, RequestContext requestContext, Map<String, String> wireAttrs, TransportCallback<RestResponse> callback) {
            clock.addDuration(5);
            switch(action.get()) {
                // success
                case 0:
                    callback.onResponse(TransportResponseImpl.success(RestResponse.NO_RESPONSE));
                    break;
                // fail with rest exception
                case 1:
                    callback.onResponse(TransportResponseImpl.error(RestException.forError(500, "rest exception")));
                    break;
                // fail with timeout exception
                case 2:
                    callback.onResponse(TransportResponseImpl.error(new RemoteInvocationException(new TimeoutException())));
                    break;
                // fail with other exception
                default:
                    callback.onResponse(TransportResponseImpl.error(new RuntimeException()));
                    break;
            }
        }

        @Override
        public void shutdown(Callback<None> callback) {
        }
    };
    TrackerClient client = createTrackerClient(tc, clock, uri);
    CallTracker callTracker = client.getCallTracker();
    CallTracker.CallStats stats;
    DegraderControl degraderControl = client.getDegraderControl(DefaultPartitionAccessor.DEFAULT_PARTITION_ID);
    client.restRequest(new RestRequestBuilder(uri).build(), new RequestContext(), new HashMap<>(), new TestTransportCallback<>());
    clock.addDuration(5000);
    stats = callTracker.getCallStats();
    Assert.assertEquals(stats.getCallCount(), 1);
    Assert.assertEquals(stats.getErrorCount(), 0);
    Assert.assertEquals(stats.getCallCountTotal(), 1);
    Assert.assertEquals(stats.getErrorCountTotal(), 0);
    Assert.assertEquals(degraderControl.getCurrentComputedDropRate(), 0.0, 0.001);
    action.set(1);
    client.restRequest(new RestRequestBuilder(uri).build(), new RequestContext(), new HashMap<>(), new TestTransportCallback<>());
    clock.addDuration(5000);
    stats = callTracker.getCallStats();
    Assert.assertEquals(stats.getCallCount(), 1);
    Assert.assertEquals(stats.getErrorCount(), 1);
    Assert.assertEquals(stats.getCallCountTotal(), 2);
    Assert.assertEquals(stats.getErrorCountTotal(), 1);
    Assert.assertEquals(degraderControl.getCurrentComputedDropRate(), 0.2, 0.001);
    action.set(2);
    client.restRequest(new RestRequestBuilder(uri).build(), new RequestContext(), new HashMap<>(), new TestTransportCallback<>());
    clock.addDuration(5000);
    stats = callTracker.getCallStats();
    Assert.assertEquals(stats.getCallCount(), 1);
    Assert.assertEquals(stats.getErrorCount(), 1);
    Assert.assertEquals(stats.getCallCountTotal(), 3);
    Assert.assertEquals(stats.getErrorCountTotal(), 2);
    Assert.assertEquals(degraderControl.getCurrentComputedDropRate(), 0.4, 0.001);
    action.set(3);
    client.restRequest(new RestRequestBuilder(uri).build(), new RequestContext(), new HashMap<>(), new TestTransportCallback<>());
    clock.addDuration(5000);
    stats = callTracker.getCallStats();
    Assert.assertEquals(stats.getCallCount(), 1);
    Assert.assertEquals(stats.getErrorCount(), 1);
    Assert.assertEquals(stats.getCallCountTotal(), 4);
    Assert.assertEquals(stats.getErrorCountTotal(), 3);
    Assert.assertEquals(degraderControl.getCurrentComputedDropRate(), 0.2, 0.001);
}

Example 3 with DegraderControl

use of com.linkedin.util.degrader.DegraderControl in project rest.li by linkedin.

the class TrackerClientTest method testCallTrackingStreamRequest.

@Test
public void testCallTrackingStreamRequest() throws Exception {
    URI uri = URI.create("http://test.qa.com:1234/foo");
    SettableClock clock = new SettableClock();
    AtomicInteger action = new AtomicInteger(0);
    TransportClient tc = new TransportClient() {

        @Override
        public void restRequest(RestRequest request, RequestContext requestContext, Map<String, String> wireAttrs, TransportCallback<RestResponse> callback) {
        }

        @Override
        public void streamRequest(StreamRequest request, RequestContext requestContext, Map<String, String> wireAttrs, TransportCallback<StreamResponse> callback) {
            clock.addDuration(5);
            switch(action.get()) {
                // success
                case 0:
                    callback.onResponse(TransportResponseImpl.success(new StreamResponseBuilder().build(EntityStreams.emptyStream())));
                    break;
                // fail with stream exception
                case 1:
                    callback.onResponse(TransportResponseImpl.error(new StreamException(new StreamResponseBuilder().setStatus(500).build(EntityStreams.emptyStream()))));
                    break;
                // fail with timeout exception
                case 2:
                    callback.onResponse(TransportResponseImpl.error(new RemoteInvocationException(new TimeoutException())));
                    break;
                // fail with other exception
                default:
                    callback.onResponse(TransportResponseImpl.error(new RuntimeException()));
                    break;
            }
        }

        @Override
        public void shutdown(Callback<None> callback) {
        }
    };
    TrackerClient client = createTrackerClient(tc, clock, uri);
    CallTracker callTracker = client.getCallTracker();
    CallTracker.CallStats stats;
    DegraderControl degraderControl = client.getDegraderControl(DefaultPartitionAccessor.DEFAULT_PARTITION_ID);
    DelayConsumeCallback delayConsumeCallback = new DelayConsumeCallback();
    client.streamRequest(new StreamRequestBuilder(uri).build(EntityStreams.emptyStream()), new RequestContext(), new HashMap<>(), delayConsumeCallback);
    clock.addDuration(5);
    // we only recorded the time when stream response arrives, but callcompletion.endcall hasn't been called yet.
    Assert.assertEquals(callTracker.getCurrentCallCountTotal(), 0);
    Assert.assertEquals(callTracker.getCurrentErrorCountTotal(), 0);
    // delay
    clock.addDuration(100);
    delayConsumeCallback.consume();
    clock.addDuration(5000);
    // now that we consumed the entity stream, callcompletion.endcall has been called.
    stats = callTracker.getCallStats();
    Assert.assertEquals(stats.getCallCount(), 1);
    Assert.assertEquals(stats.getErrorCount(), 0);
    Assert.assertEquals(stats.getCallCountTotal(), 1);
    Assert.assertEquals(stats.getErrorCountTotal(), 0);
    Assert.assertEquals(degraderControl.getCurrentComputedDropRate(), 0.0, 0.001);
    action.set(1);
    client.streamRequest(new StreamRequestBuilder(uri).build(EntityStreams.emptyStream()), new RequestContext(), new HashMap<>(), delayConsumeCallback);
    clock.addDuration(5);
    // we endcall with error immediately for stream exception, even before the entity is consumed
    Assert.assertEquals(callTracker.getCurrentCallCountTotal(), 2);
    Assert.assertEquals(callTracker.getCurrentErrorCountTotal(), 1);
    delayConsumeCallback.consume();
    clock.addDuration(5000);
    // no change in tracking after entity is consumed
    stats = callTracker.getCallStats();
    Assert.assertEquals(stats.getCallCount(), 1);
    Assert.assertEquals(stats.getErrorCount(), 1);
    Assert.assertEquals(stats.getCallCountTotal(), 2);
    Assert.assertEquals(stats.getErrorCountTotal(), 1);
    Assert.assertEquals(degraderControl.getCurrentComputedDropRate(), 0.2, 0.001);
    action.set(2);
    client.streamRequest(new StreamRequestBuilder(uri).build(EntityStreams.emptyStream()), new RequestContext(), new HashMap<>(), new TestTransportCallback<>());
    clock.addDuration(5);
    Assert.assertEquals(callTracker.getCurrentCallCountTotal(), 3);
    Assert.assertEquals(callTracker.getCurrentErrorCountTotal(), 2);
    clock.addDuration(5000);
    stats = callTracker.getCallStats();
    Assert.assertEquals(stats.getCallCount(), 1);
    Assert.assertEquals(stats.getErrorCount(), 1);
    Assert.assertEquals(stats.getCallCountTotal(), 3);
    Assert.assertEquals(stats.getErrorCountTotal(), 2);
    Assert.assertEquals(degraderControl.getCurrentComputedDropRate(), 0.4, 0.001);
    action.set(3);
    client.streamRequest(new StreamRequestBuilder(uri).build(EntityStreams.emptyStream()), new RequestContext(), new HashMap<>(), new TestTransportCallback<>());
    clock.addDuration(5);
    Assert.assertEquals(callTracker.getCurrentCallCountTotal(), 4);
    Assert.assertEquals(callTracker.getCurrentErrorCountTotal(), 3);
    clock.addDuration(5000);
    stats = callTracker.getCallStats();
    Assert.assertEquals(stats.getCallCount(), 1);
    Assert.assertEquals(stats.getErrorCount(), 1);
    Assert.assertEquals(stats.getCallCountTotal(), 4);
    Assert.assertEquals(stats.getErrorCountTotal(), 3);
    Assert.assertEquals(degraderControl.getCurrentComputedDropRate(), 0.2, 0.001);
}

Example 4 with DegraderControl

use of com.linkedin.util.degrader.DegraderControl in project rest.li by linkedin.

the class DegraderLoadBalancerTest method testHighLowWatermarks.

@Test(groups = { "small", "back-end" })
public void testHighLowWatermarks() {
    final int NUM_CHECKS = 5;
    Map<String, Object> myMap = new HashMap<String, Object>();
    Long timeInterval = 5000L;
    double globalStepUp = 0.4;
    double globalStepDown = 0.4;
    double highWaterMark = 1000;
    double lowWaterMark = 50;
    TestClock clock = new TestClock();
    myMap.put(PropertyKeys.CLOCK, clock);
    myMap.put(PropertyKeys.HTTP_LB_STRATEGY_PROPERTIES_UPDATE_INTERVAL_MS, timeInterval);
    myMap.put(PropertyKeys.HTTP_LB_GLOBAL_STEP_UP, globalStepUp);
    myMap.put(PropertyKeys.HTTP_LB_GLOBAL_STEP_DOWN, globalStepDown);
    myMap.put(PropertyKeys.HTTP_LB_HIGH_WATER_MARK, highWaterMark);
    myMap.put(PropertyKeys.HTTP_LB_LOW_WATER_MARK, lowWaterMark);
    myMap.put(PropertyKeys.HTTP_LB_CLUSTER_MIN_CALL_COUNT_HIGH_WATER_MARK, 1l);
    myMap.put(PropertyKeys.HTTP_LB_CLUSTER_MIN_CALL_COUNT_LOW_WATER_MARK, 1l);
    DegraderLoadBalancerStrategyConfig config = DegraderLoadBalancerStrategyConfig.createHttpConfigFromMap(myMap);
    DegraderLoadBalancerStrategyV3 strategy = new DegraderLoadBalancerStrategyV3(config, "DegraderLoadBalancerTest", null);
    List<TrackerClient> clients = new ArrayList<TrackerClient>();
    URI uri1 = URI.create("http://test.linkedin.com:3242/fdsaf");
    URIRequest request = new URIRequest(uri1);
    TrackerClient client1 = new TrackerClient(uri1, getDefaultPartitionData(1d), new TestLoadBalancerClient(uri1), clock, null);
    clients.add(client1);
    DegraderControl dcClient1Default = client1.getDegraderControl(DEFAULT_PARTITION_ID);
    dcClient1Default.setOverrideMinCallCount(5);
    dcClient1Default.setMinCallCount(5);
    List<CallCompletion> ccList = new ArrayList<CallCompletion>();
    CallCompletion cc;
    TrackerClient resultTC = getTrackerClient(strategy, request, new RequestContext(), 1, clients);
    // The override drop rate should be zero at this point.
    assertEquals(dcClient1Default.getOverrideDropRate(), 0.0);
    // make high latency calls to the tracker client, verify the override drop rate doesn't change
    for (int j = 0; j < NUM_CHECKS; j++) {
        cc = client1.getCallTracker().startCall();
        ccList.add(cc);
    }
    clock.addMs((long) highWaterMark);
    for (Iterator<CallCompletion> iter = ccList.listIterator(); iter.hasNext(); ) {
        cc = iter.next();
        cc.endCall();
        iter.remove();
    }
    // go to next time interval.
    clock.addMs(timeInterval);
    // try call dropping on the next updateState
    strategy.setStrategy(DEFAULT_PARTITION_ID, DegraderLoadBalancerStrategyV3.PartitionDegraderLoadBalancerState.Strategy.CALL_DROPPING);
    resultTC = getTrackerClient(strategy, request, new RequestContext(), 1, clients);
    // we now expect that the override drop rate stepped up because updateState
    // made that decision.
    assertEquals(dcClient1Default.getOverrideDropRate(), globalStepUp);
    // make mid latency calls to the tracker client, verify the override drop rate doesn't change
    for (int j = 0; j < NUM_CHECKS; j++) {
        // need to use client1 because the resultTC may be null
        cc = client1.getCallTracker().startCall();
        ccList.add(cc);
    }
    clock.addMs((long) highWaterMark - 1);
    for (Iterator<CallCompletion> iter = ccList.listIterator(); iter.hasNext(); ) {
        cc = iter.next();
        cc.endCall();
        iter.remove();
    }
    // go to next time interval.
    clock.addMs(timeInterval);
    double previousOverrideDropRate = dcClient1Default.getOverrideDropRate();
    // try call dropping on the next updateState
    strategy.setStrategy(DEFAULT_PARTITION_ID, DegraderLoadBalancerStrategyV3.PartitionDegraderLoadBalancerState.Strategy.CALL_DROPPING);
    resultTC = getTrackerClient(strategy, request, new RequestContext(), 1, clients);
    assertEquals(dcClient1Default.getOverrideDropRate(), previousOverrideDropRate);
    // make low latency calls to the tracker client, verify the override drop rate decreases
    for (int j = 0; j < NUM_CHECKS; j++) {
        cc = client1.getCallTracker().startCall();
        ccList.add(cc);
    }
    clock.addMs((long) lowWaterMark);
    for (Iterator<CallCompletion> iter = ccList.listIterator(); iter.hasNext(); ) {
        cc = iter.next();
        cc.endCall();
        iter.remove();
    }
    // go to next time interval.
    clock.addMs(timeInterval);
    // try Call dropping on this updateState
    strategy.setStrategy(DEFAULT_PARTITION_ID, DegraderLoadBalancerStrategyV3.PartitionDegraderLoadBalancerState.Strategy.CALL_DROPPING);
    resultTC = getTrackerClient(strategy, request, new RequestContext(), 1, clients);
    assertEquals(resultTC.getDegraderControl(DEFAULT_PARTITION_ID).getOverrideDropRate(), 0.0);
}

Example 5 with DegraderControl

use of com.linkedin.util.degrader.DegraderControl in project rest.li by linkedin.

the class DegraderLoadBalancerTest method testClusterRecovery2TC.

@Test(groups = { "small", "back-end" })
public void testClusterRecovery2TC() {
    final int NUM_CHECKS = 5;
    final Long TIME_INTERVAL = 5000L;
    Map<String, Object> myMap = new HashMap<String, Object>();
    // 1,2,4,8,16,32,64,100% steps, given a 2x recovery step coefficient
    int localStepsToFullRecovery = 8;
    myMap.put(PropertyKeys.HTTP_LB_INITIAL_RECOVERY_LEVEL, 0.005);
    myMap.put(PropertyKeys.HTTP_LB_RING_RAMP_FACTOR, 2d);
    myMap.put(PropertyKeys.HTTP_LB_STRATEGY_PROPERTIES_UPDATE_INTERVAL_MS, TIME_INTERVAL);
    TestClock clock = new TestClock();
    myMap.put(PropertyKeys.CLOCK, clock);
    DegraderLoadBalancerStrategyConfig config = DegraderLoadBalancerStrategyConfig.createHttpConfigFromMap(myMap);
    DegraderLoadBalancerStrategyV3 strategy = new DegraderLoadBalancerStrategyV3(config, "DegraderLoadBalancerTest", null);
    List<TrackerClient> clients = new ArrayList<TrackerClient>();
    URI uri1 = URI.create("http://test.linkedin.com:3242/fdsaf");
    URI uri2 = URI.create("http://test.linkedin.com:3243/fdsaf");
    URIRequest request = new URIRequest(uri1);
    List<CallCompletion> ccList = new ArrayList<CallCompletion>();
    CallCompletion cc;
    TrackerClient client1 = new TrackerClient(uri1, getDefaultPartitionData(1d), new TestLoadBalancerClient(uri1), clock, null);
    TrackerClient client2 = new TrackerClient(uri2, getDefaultPartitionData(1d), new TestLoadBalancerClient(uri2), clock, null);
    clients.add(client1);
    clients.add(client2);
    // force client1 to be disabled if we encounter errors/high latency
    DegraderControl dcClient1Default = client1.getDegraderControl(DEFAULT_PARTITION_ID);
    dcClient1Default.setMinCallCount(5);
    dcClient1Default.setOverrideMinCallCount(5);
    dcClient1Default.setUpStep(1.0);
    // force client2 to be disabled if we encounter errors/high latency
    DegraderControl dcClient2Default = client2.getDegraderControl(DEFAULT_PARTITION_ID);
    dcClient2Default.setOverrideMinCallCount(5);
    dcClient2Default.setMinCallCount(5);
    dcClient2Default.setUpStep(0.4);
    // Have one cycle of successful calls to verify valid tracker clients returned.
    // try load balancing on this updateState, need to updateState before forcing the strategy.
    TrackerClient resultTC = getTrackerClient(strategy, request, new RequestContext(), 1, clients);
    strategy.setStrategy(DEFAULT_PARTITION_ID, DegraderLoadBalancerStrategyV3.PartitionDegraderLoadBalancerState.Strategy.LOAD_BALANCE);
    resultTC = getTrackerClient(strategy, request, new RequestContext(), 1, clients);
    assertNotNull(resultTC, "expected non-null trackerclient");
    for (int j = 0; j < NUM_CHECKS; j++) {
        ccList.add(client1.getCallTracker().startCall());
        ccList.add(client2.getCallTracker().startCall());
    }
    clock.addMs(1);
    for (Iterator<CallCompletion> iter = ccList.listIterator(); iter.hasNext(); ) {
        cc = iter.next();
        cc.endCall();
    }
    // bump to next interval, and get stats.
    clock.addMs(5000);
    // try Load balancing on this updateState
    strategy.setStrategy(DEFAULT_PARTITION_ID, DegraderLoadBalancerStrategyV3.PartitionDegraderLoadBalancerState.Strategy.LOAD_BALANCE);
    resultTC = getTrackerClient(strategy, request, new RequestContext(), 1, clients);
    assertNotNull(resultTC, "expected non-null trackerclient");
    Assert.assertEquals(dcClient1Default.getCurrentComputedDropRate(), 0.0);
    Assert.assertEquals(dcClient2Default.getCurrentComputedDropRate(), 0.0);
    // now simulate a bad cluster state with high error and high latency
    for (int j = 0; j < NUM_CHECKS; j++) {
        ccList.add(client1.getCallTracker().startCall());
        ccList.add(client2.getCallTracker().startCall());
    }
    clock.addMs(3500);
    for (Iterator<CallCompletion> iter = ccList.listIterator(); iter.hasNext(); ) {
        cc = iter.next();
        cc.endCallWithError();
    }
    // go to next interval
    clock.addMs(5000);
    Assert.assertEquals(dcClient1Default.getCurrentComputedDropRate(), 1.0);
    Assert.assertEquals(dcClient2Default.getCurrentComputedDropRate(), 0.4);
    // trigger a state update, the returned TrackerClient should be client2
    // because client 1 should have gone up to a 1.0 drop rate, and the cluster should
    // be unhealthy
    strategy.setStrategy(DEFAULT_PARTITION_ID, DegraderLoadBalancerStrategyV3.PartitionDegraderLoadBalancerState.Strategy.LOAD_BALANCE);
    resultTC = getTrackerClient(strategy, request, new RequestContext(), 1, clients);
    assertEquals(resultTC, client2);
    // it's current drop rate.
    do {
        // go to next time interval.
        clock.addMs(TIME_INTERVAL);
        // adjust the hash ring this time.
        strategy.setStrategy(DEFAULT_PARTITION_ID, DegraderLoadBalancerStrategyV3.PartitionDegraderLoadBalancerState.Strategy.LOAD_BALANCE);
        resultTC = getTrackerClient(strategy, request, new RequestContext(), 1, clients);
        localStepsToFullRecovery--;
    } while (localStepsToFullRecovery > 0);
    assertNotNull(resultTC, "expected non-null trackerclient");
    assertTrue(strategy.getState().getPartitionState(DEFAULT_PARTITION_ID).getPointsMap().get(client1.getUri()) == client1.getPartitionWeight(DEFAULT_PARTITION_ID) * config.getPointsPerWeight(), "client1 did not recover to full weight in hash map.");
    Assert.assertEquals(dcClient2Default.getCurrentComputedDropRate(), 0.4, "client2 drop rate not as expected");
    cc = client1.getCallTracker().startCall();
    clock.addMs(10);
    cc.endCall();
    clock.addMs(TIME_INTERVAL);
    resultTC = getTrackerClient(strategy, request, new RequestContext(), 1, clients);
    assertNotNull(resultTC, "expected non-null trackerclient");
}