Examples with Ring com.linkedin.d2.balancer.util.hashing.Ring used on opensource projects

Example 11 with Ring

use of com.linkedin.d2.balancer.util.hashing.Ring in project rest.li by linkedin.

the class DegraderLoadBalancerStrategyV2_1 method getTrackerClient.

@Override
public TrackerClient getTrackerClient(Request request, RequestContext requestContext, long clusterGenerationId, int partitionId, List<TrackerClient> trackerClients) {
    if (partitionId != DEFAULT_PARTITION_ID) {
        throw new UnsupportedOperationException("Trying to access partition: " + partitionId + "on an unpartitioned cluster");
    }
    debug(_log, "getTrackerClient with generation id ", clusterGenerationId, " on tracker clients: ", clusterGenerationId);
    if (trackerClients == null || trackerClients.size() == 0) {
        warn(_log, "getTrackerClient called with null/empty trackerClients, so returning null");
        return null;
    }
    // only one thread will be allowed to enter updateState.
    checkUpdateState(clusterGenerationId, trackerClients);
    URI targetHostUri = KeyMapper.TargetHostHints.getRequestContextTargetHost(requestContext);
    Set<URI> excludedUris = ExcludedHostHints.getRequestContextExcludedHosts(requestContext);
    URI hostHeaderUri = targetHostUri;
    //no valid target host header was found in the request
    if (targetHostUri == null) {
        // Compute the hash code
        int hashCode = _hashFunction.hash(request);
        // we operate only on URIs to ensure that we never hold on to an old tracker client
        // that the cluster manager has removed
        Ring<URI> ring = _state.getRing();
        Iterator<URI> iterator = ring.getIterator(hashCode);
        while (iterator.hasNext() && targetHostUri == null) {
            URI uri = iterator.next();
            if (excludedUris == null || !excludedUris.contains(uri)) {
                targetHostUri = uri;
            }
        }
        ExcludedHostHints.addRequestContextExcludedHost(requestContext, targetHostUri);
    } else {
        debug(_log, "Degrader honoring target host header in request, skipping hashing.  URI: " + targetHostUri.toString());
    }
    TrackerClient client = null;
    if (targetHostUri != null) {
        // consistent hash ring! Therefore, this linear scan is the best we can do.
        for (TrackerClient trackerClient : trackerClients) {
            if (trackerClient.getUri().equals(targetHostUri)) {
                client = trackerClient;
                break;
            }
        }
        if (client == null) {
            warn(_log, "No client found for " + targetHostUri + (hostHeaderUri == null ? ", degrader load balancer state is inconsistent with cluster manager" : ", target host specified is no longer part of cluster"));
        }
    } else {
        warn(_log, "unable to find a URI to use");
    }
    boolean dropCall = client == null;
    if (!dropCall) {
        dropCall = client.getDegrader(DEFAULT_PARTITION_ID).checkDrop();
        if (dropCall) {
            warn(_log, "client's degrader is dropping call for: ", client);
        } else {
            debug(_log, "returning client: ", client);
        }
    }
    return (!dropCall) ? client : null;
}

Example 12 with Ring

use of com.linkedin.d2.balancer.util.hashing.Ring in project rest.li by linkedin.

the class DegraderLoadBalancerStrategyV2_1 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(double newOverrideDropRate, List<TrackerClientUpdater> trackerClientUpdaters, Map<URI, Integer> pointsMap, int pointsPerWeight) {
    for (TrackerClientUpdater clientUpdater : trackerClientUpdaters) {
        TrackerClient client = clientUpdater.getTrackerClient();
        int currentOverrideMinCallCount = client.getDegraderControl(DEFAULT_PARTITION_ID).getOverrideMinCallCount();
        double hashFactor = pointsMap.get(client.getUri()) / pointsPerWeight;
        double transmitFactor = 1.0 - newOverrideDropRate;
        int newOverrideMinCallCount = (int) Math.max(Math.round(client.getDegraderControl(DEFAULT_PARTITION_ID).getMinCallCount() * hashFactor * transmitFactor), 1);
        if (newOverrideMinCallCount != currentOverrideMinCallCount) {
            clientUpdater.setOverrideMinCallCount(newOverrideMinCallCount);
            warn(_log, "overriding Min Call Count to ", newOverrideMinCallCount, " for client: ", client.getUri());
        }
    }
}

Example 13 with Ring

use of com.linkedin.d2.balancer.util.hashing.Ring in project rest.li by linkedin.

the class SimpleLoadBalancerTest method testGetPartitionInfoOrdering.

/**
   * This tests the getPartitionInfo() when given a collection of keys (actually a test for KeyMapper.mapKeysV3()).
   */
@Test
public void testGetPartitionInfoOrdering() throws Exception {
    String serviceName = "articles";
    String clusterName = "cluster";
    String path = "path";
    String strategyName = "degrader";
    // setup 3 partitions. Partition 1 and Partition 2 both have server1 - server3. Partition 3 only has server1.
    Map<URI, Map<Integer, PartitionData>> partitionDescriptions = new HashMap<URI, Map<Integer, PartitionData>>();
    final URI server1 = new URI("http://foo1.com");
    Map<Integer, PartitionData> server1Data = new HashMap<Integer, PartitionData>();
    server1Data.put(1, new PartitionData(1.0));
    server1Data.put(2, new PartitionData(1.0));
    server1Data.put(3, new PartitionData(1.0));
    partitionDescriptions.put(server1, server1Data);
    final URI server2 = new URI("http://foo2.com");
    Map<Integer, PartitionData> server2Data = new HashMap<Integer, PartitionData>();
    server2Data.put(1, new PartitionData(1.0));
    server2Data.put(2, new PartitionData(1.0));
    partitionDescriptions.put(server2, server2Data);
    final URI server3 = new URI("http://foo3.com");
    Map<Integer, PartitionData> server3Data = new HashMap<Integer, PartitionData>();
    server3Data.put(1, new PartitionData(1.0));
    server3Data.put(2, new PartitionData(1.0));
    partitionDescriptions.put(server3, server3Data);
    //setup strategy which involves tweaking the hash ring to get partitionId -> URI host
    List<LoadBalancerState.SchemeStrategyPair> orderedStrategies = new ArrayList<LoadBalancerState.SchemeStrategyPair>();
    LoadBalancerStrategy strategy = new TestLoadBalancerStrategy(partitionDescriptions);
    orderedStrategies.add(new LoadBalancerState.SchemeStrategyPair("http", strategy));
    //setup the partition accessor which can only map keys from 1 - 3.
    PartitionAccessor accessor = new TestPartitionAccessor();
    URI serviceURI = new URI("d2://" + serviceName);
    SimpleLoadBalancer balancer = new SimpleLoadBalancer(new PartitionedLoadBalancerTestState(clusterName, serviceName, path, strategyName, partitionDescriptions, orderedStrategies, accessor));
    List<Integer> keys = new ArrayList<Integer>();
    keys.add(1);
    keys.add(2);
    keys.add(3);
    keys.add(123);
    HostToKeyMapper<Integer> result = balancer.getPartitionInformation(serviceURI, keys, 3, 123);
    Assert.assertEquals(result.getLimitHostPerPartition(), 3);
    Assert.assertEquals(1, result.getUnmappedKeys().size());
    Assert.assertEquals(123, (int) result.getUnmappedKeys().iterator().next().getKey());
    //partition 0 should be null
    Assert.assertNull(result.getPartitionInfoMap().get(0));
    // results for partition 1 should contain server1, server2 and server3
    KeysAndHosts<Integer> keysAndHosts1 = result.getPartitionInfoMap().get(1);
    Assert.assertTrue(keysAndHosts1.getKeys().size() == 1);
    Assert.assertTrue(keysAndHosts1.getKeys().iterator().next() == 1);
    List<URI> ordering1 = keysAndHosts1.getHosts();
    // results for partition 2 should be the same as partition1.
    KeysAndHosts<Integer> keysAndHosts2 = result.getPartitionInfoMap().get(2);
    Assert.assertTrue(keysAndHosts2.getKeys().size() == 1);
    Assert.assertTrue(keysAndHosts2.getKeys().iterator().next() == 2);
    List<URI> ordering2 = keysAndHosts2.getHosts();
    //for partition 3
    KeysAndHosts<Integer> keysAndHosts3 = result.getPartitionInfoMap().get(3);
    Assert.assertTrue(keysAndHosts3.getKeys().size() == 1);
    Assert.assertTrue(keysAndHosts3.getKeys().iterator().next() == 3);
    List<URI> ordering3 = keysAndHosts3.getHosts();
    // Just compare the size and contents of the list, not the ordering.
    Assert.assertTrue(ordering1.size() == 3);
    List<URI> allServers = new ArrayList<>();
    allServers.add(server1);
    allServers.add(server2);
    allServers.add(server3);
    Assert.assertTrue(ordering1.containsAll(allServers));
    Assert.assertTrue(ordering2.containsAll(allServers));
    Assert.assertEquals(ordering1, ordering2);
    Assert.assertEquals(ordering3.get(0), server1);
    Assert.assertTrue(result.getPartitionsWithoutEnoughHosts().containsKey(3));
    Assert.assertEquals((int) result.getPartitionsWithoutEnoughHosts().get(3), 2);
}

Example 14 with Ring

use of com.linkedin.d2.balancer.util.hashing.Ring in project rest.li by linkedin.

the class SimpleLoadBalancerTest method testGetAllPartitionMultipleHostsOrdering.

/**
   * This tests the getPartitionInfo() when keys are null (actually a test for KeyMapper.getAllPartitionMultipleHosts()).
   */
@Test
public void testGetAllPartitionMultipleHostsOrdering() throws Exception {
    String serviceName = "articles";
    String clusterName = "cluster";
    String path = "path";
    String strategyName = "degrader";
    //setup partition
    Map<URI, Map<Integer, PartitionData>> partitionDescriptions = new HashMap<URI, Map<Integer, PartitionData>>();
    final URI server1 = new URI("http://foo1.com");
    Map<Integer, PartitionData> server1Data = new HashMap<Integer, PartitionData>();
    server1Data.put(1, new PartitionData(1.0));
    server1Data.put(2, new PartitionData(1.0));
    server1Data.put(3, new PartitionData(1.0));
    partitionDescriptions.put(server1, server1Data);
    final URI server2 = new URI("http://foo2.com");
    Map<Integer, PartitionData> server2Data = new HashMap<Integer, PartitionData>();
    server2Data.put(1, new PartitionData(1.0));
    server2Data.put(2, new PartitionData(1.0));
    //server2Data.put(3, new PartitionData(1.0));
    partitionDescriptions.put(server2, server2Data);
    final URI server3 = new URI("http://foo3.com");
    Map<Integer, PartitionData> server3Data = new HashMap<Integer, PartitionData>();
    server3Data.put(1, new PartitionData(1.0));
    server3Data.put(2, new PartitionData(1.0));
    //server3Data.put(3, new PartitionData(1.0));
    partitionDescriptions.put(server3, server3Data);
    //setup strategy which involves tweaking the hash ring to get partitionId -> URI host
    List<LoadBalancerState.SchemeStrategyPair> orderedStrategies = new ArrayList<LoadBalancerState.SchemeStrategyPair>();
    LoadBalancerStrategy strategy = new TestLoadBalancerStrategy(partitionDescriptions);
    orderedStrategies.add(new LoadBalancerState.SchemeStrategyPair("http", strategy));
    //setup the partition accessor which is used to get partitionId -> keys
    PartitionAccessor accessor = new TestPartitionAccessor();
    URI serviceURI = new URI("d2://" + serviceName);
    SimpleLoadBalancer balancer = new SimpleLoadBalancer(new PartitionedLoadBalancerTestState(clusterName, serviceName, path, strategyName, partitionDescriptions, orderedStrategies, accessor));
    HostToKeyMapper<URI> result = balancer.getPartitionInformation(serviceURI, null, 3, 123);
    Assert.assertEquals(result.getPartitionInfoMap().size(), 4);
    Assert.assertEquals(4, result.getPartitionCount());
    // partition 0 should be empty
    Assert.assertTrue(result.getPartitionInfoMap().get(0).getHosts().isEmpty());
    // partition 1 should have server1, server2 and server3.
    List<URI> ordering1 = result.getPartitionInfoMap().get(1).getHosts();
    List<URI> allServers = new ArrayList<>();
    allServers.add(server1);
    allServers.add(server2);
    allServers.add(server3);
    Assert.assertTrue(ordering1.size() == 3);
    Assert.assertTrue(ordering1.containsAll(allServers));
    // partition 2 should be the same as partition 1
    List<URI> ordering2 = result.getPartitionInfoMap().get(2).getHosts();
    Assert.assertEquals(ordering1, ordering2);
    // partition 3 should only contain server1
    List<URI> ordering3 = result.getPartitionInfoMap().get(3).getHosts();
    Assert.assertEquals(ordering3.get(0), server1);
    // partition 0 and partition 3 should not have enough hosts: lacking 3 and 2 respectively.
    Assert.assertTrue(result.getPartitionsWithoutEnoughHosts().containsKey(3));
    Assert.assertTrue(result.getPartitionsWithoutEnoughHosts().containsKey(0));
    Assert.assertEquals((int) result.getPartitionsWithoutEnoughHosts().get(3), 2);
    Assert.assertEquals((int) result.getPartitionsWithoutEnoughHosts().get(0), 3);
}

Example 15 with Ring

use of com.linkedin.d2.balancer.util.hashing.Ring in project rest.li by linkedin.

the class DegraderLoadBalancerTest method testInconsistentHashAndTrackerclients.

@Test(groups = { "small", "back-end" }, dataProvider = "consistentHashAlgorithms")
public void testInconsistentHashAndTrackerclients(String consistentHashAlgorithm) throws URISyntaxException, InterruptedException {
    // check if the inconsistent Hash ring and trackerlients can be handled
    TestClock clock = new TestClock();
    Map<String, Object> myMap = new HashMap<String, Object>();
    myMap.put(PropertyKeys.CLOCK, clock);
    myMap.put(PropertyKeys.HTTP_LB_CONSISTENT_HASH_ALGORITHM, consistentHashAlgorithm);
    DegraderLoadBalancerStrategyConfig config = DegraderLoadBalancerStrategyConfig.createHttpConfigFromMap(myMap);
    DegraderLoadBalancerStrategyV3 strategy = new DegraderLoadBalancerStrategyV3(config, "DegraderLoadBalancerTest", null);
    List<TrackerClient> clients = new ArrayList<TrackerClient>();
    clients.add(getClient(URI.create("http://test.linkedin.com:3242/fdsaf"), clock));
    clients.add(getClient(URI.create("http://test.linkedin.com:3243/fdsaf"), clock));
    TrackerClient chosen = getTrackerClient(strategy, null, new RequestContext(), 0, clients);
    assertNotNull(chosen);
    // remove the client from the list, now the ring and the trackerClient list are inconsistent
    clients.remove(chosen);
    assertNotNull(getTrackerClient(strategy, null, new RequestContext(), 0, clients));
    // update the hash ring we should get the results as well
    assertNotNull(getTrackerClient(strategy, null, new RequestContext(), 1, clients));
}