Examples with KeyMapper com.linkedin.d2.balancer.KeyMapper used on opensource projects

Example 1 with KeyMapper

use of com.linkedin.d2.balancer.KeyMapper in project rest.li by linkedin.

the class SimpleLoadBalancer method chooseTrackerClient.

private TrackerClient chooseTrackerClient(Request request, RequestContext requestContext, String serviceName, String clusterName, ClusterProperties cluster, LoadBalancerStateItem<UriProperties> uriItem, UriProperties uris, List<LoadBalancerState.SchemeStrategyPair> orderedStrategies, ServiceProperties serviceProperties) throws ServiceUnavailableException {
    // now try and find a tracker client for the uri
    TrackerClient trackerClient = null;
    URI targetHost = KeyMapper.TargetHostHints.getRequestContextTargetHost(requestContext);
    int partitionId = -1;
    URI requestUri = request.getURI();
    if (targetHost == null) {
        PartitionAccessor accessor = getPartitionAccessor(serviceName, clusterName);
        try {
            partitionId = accessor.getPartitionId(requestUri);
        } catch (PartitionAccessException e) {
            die(serviceName, "PEGA_1013. Error in finding the partition for URI: " + requestUri + ", " + "in cluster: " + clusterName + ", " + e.getMessage());
        }
    } else {
        // This is the case of scatter/gather or search, where the target host may be chosen to be responsible for
        // more than one partitions (The target host was picked from a consistent hash ring, so load balancing is already in effect).
        // we randomly pick one partition to check for the call dropping
        // This is done for two reasons:
        // 1. Currently there is no way to know for which subset of partitions the target host is chosen for
        // if it is serving more than one partitions. This can be added, but it requires the change of public interfaces (KeyMapper) so that
        // more hints can be added to the request context for the concerned the partitions
        // 2. More importantly, there is no good way to check for call dropping even if the above problem is solved.
        // For example, if a target host is chosen for partition 1, 5, 7, with call drop rates of 0, 0.2, 0.4 respectively
        // A reasonable way to proceed would be use the highest drop rate and do the check once for the target host,
        // but currently the check can only be done for each partition and only with boolean result (no access to drop rate)
        // The partition to check is picked at random to be conservative.
        // E.g. in the above example, we don't want to always use the drop rate of partition 1.
        Map<Integer, PartitionData> partitionDataMap = uris.getPartitionDataMap(targetHost);
        if (partitionDataMap == null || partitionDataMap.isEmpty()) {
            die(serviceName, "PEGA_1014. There is no partition data for server host: " + targetHost + ". URI: " + requestUri);
        }
        Set<Integer> partitions = partitionDataMap.keySet();
        Iterator<Integer> iterator = partitions.iterator();
        int index = _random.nextInt(partitions.size());
        for (int i = 0; i <= index; i++) {
            partitionId = iterator.next();
        }
    }
    Map<URI, TrackerClient> clientsToLoadBalance = null;
    for (LoadBalancerState.SchemeStrategyPair pair : orderedStrategies) {
        LoadBalancerStrategy strategy = pair.getStrategy();
        String scheme = pair.getScheme();
        TrackerClientSubsetItem subsetItem = getPotentialClients(serviceName, serviceProperties, cluster, uris, scheme, partitionId, uriItem.getVersion());
        clientsToLoadBalance = subsetItem.getWeightedSubset();
        trackerClient = strategy.getTrackerClient(request, requestContext, uriItem.getVersion(), partitionId, clientsToLoadBalance, subsetItem.shouldForceUpdate());
        debug(_log, "load balancer strategy for ", serviceName, " returned: ", trackerClient);
        // break as soon as we find an available cluster client
        if (trackerClient != null) {
            break;
        }
    }
    if (trackerClient == null) {
        if (clientsToLoadBalance == null || clientsToLoadBalance.isEmpty()) {
            String requestedSchemes = orderedStrategies.stream().map(LoadBalancerState.SchemeStrategyPair::getScheme).collect(Collectors.joining(","));
            die(serviceName, "PEGA_1015. Service: " + serviceName + " unable to find a host to route the request" + " in partition: " + partitionId + " cluster: " + clusterName + " scheme: [" + requestedSchemes + "]," + " total hosts in cluster: " + uris.Uris().size() + "." + " Check what cluster and scheme your servers are announcing to.");
        } else {
            die(serviceName, "PEGA_1016. Service: " + serviceName + " is in a bad state (high latency/high error). " + "Dropping request. Cluster: " + clusterName + ", partitionId:" + partitionId + " (choosable: " + clientsToLoadBalance.size() + " hosts, total in cluster: " + uris.Uris().size() + ")");
        }
    }
    return trackerClient;
}

Example 2 with KeyMapper

use of com.linkedin.d2.balancer.KeyMapper in project rest.li by linkedin.

the class ZKFSTest method testKeyMapper.

@Test
public void testKeyMapper() throws Exception {
    final String TEST_SERVICE_NAME = "test-service";
    final String TEST_CLUSTER_NAME = "test-cluster";
    final URI TEST_SERVER_URI1 = URI.create("http://test-host-1/");
    final URI TEST_SERVER_URI2 = URI.create("http://test-host-2/");
    final int NUM_ITERATIONS = 5;
    startServer();
    try {
        ZKFSLoadBalancer balancer = getBalancer();
        FutureCallback<None> callback = new FutureCallback<>();
        balancer.start(callback);
        callback.get(30, TimeUnit.SECONDS);
        ZKConnection conn = balancer.zkConnection();
        ZooKeeperPermanentStore<ServiceProperties> serviceStore = new ZooKeeperPermanentStore<>(conn, new ServicePropertiesJsonSerializer(), ZKFSUtil.servicePath(BASE_PATH));
        ServiceProperties props = new ServiceProperties(TEST_SERVICE_NAME, TEST_CLUSTER_NAME, "/test", Arrays.asList("degrader"), Collections.<String, Object>emptyMap(), null, null, Arrays.asList("http"), null);
        serviceStore.put(TEST_SERVICE_NAME, props);
        ClusterProperties clusterProperties = new ClusterProperties(TEST_CLUSTER_NAME);
        ZooKeeperPermanentStore<ClusterProperties> clusterStore = new ZooKeeperPermanentStore<>(conn, new ClusterPropertiesJsonSerializer(), ZKFSUtil.clusterPath(BASE_PATH));
        clusterStore.put(TEST_CLUSTER_NAME, clusterProperties);
        ZooKeeperEphemeralStore<UriProperties> uriStore = new ZooKeeperEphemeralStore<>(conn, new UriPropertiesJsonSerializer(), new UriPropertiesMerger(), ZKFSUtil.uriPath(BASE_PATH), false, true);
        Map<URI, Map<Integer, PartitionData>> uriData = new HashMap<>();
        Map<Integer, PartitionData> partitionData = new HashMap<>(1);
        partitionData.put(DefaultPartitionAccessor.DEFAULT_PARTITION_ID, new PartitionData(1.0d));
        uriData.put(TEST_SERVER_URI1, partitionData);
        uriData.put(TEST_SERVER_URI2, partitionData);
        UriProperties uriProps = new UriProperties(TEST_CLUSTER_NAME, uriData);
        callback = new FutureCallback<>();
        uriStore.start(callback);
        callback.get(30, TimeUnit.SECONDS);
        uriStore.put(TEST_CLUSTER_NAME, uriProps);
        Set<Integer> keys = new HashSet<>();
        for (int ii = 0; ii < 100; ++ii) {
            keys.add(ii);
        }
        for (int ii = 0; ii < NUM_ITERATIONS; ++ii) {
            KeyMapper mapper = balancer.getKeyMapper();
            MapKeyResult<URI, Integer> batches = mapper.mapKeysV2(URI.create("d2://" + TEST_SERVICE_NAME), keys);
            Assert.assertEquals(batches.getMapResult().size(), 2);
            for (Map.Entry<URI, Collection<Integer>> oneBatch : batches.getMapResult().entrySet()) {
                Assert.assertTrue(oneBatch.getKey().toString().startsWith("http://test-host-"));
                Assert.assertTrue(keys.containsAll(oneBatch.getValue()));
            }
        }
    } finally {
        stopServer();
    }
}

Example 3 with KeyMapper

use of com.linkedin.d2.balancer.KeyMapper in project rest.li by linkedin.

the class TestScatterGather method testScatterGatherKVLoadBalancerIntegration.

@Test(dataProvider = "requestBuilderDataProvider")
public static void testScatterGatherKVLoadBalancerIntegration(RootBuilderWrapper<Long, Greeting> builders) throws Exception {
    SimpleLoadBalancer loadBalancer = MockLBFactory.createLoadBalancer();
    KeyMapper keyMapper = new ConsistentHashKeyMapper(loadBalancer, new TestPartitionInfoProvider());
    try {
        keyMapper.mapKeysV2(URI.create("http://badurischeme/"), new HashSet<String>());
        Assert.fail("keyMapper should reject non-D2 URI scheme");
    } catch (IllegalArgumentException e) {
    // expected
    }
    ScatterGatherBuilder<Greeting> sg = new ScatterGatherBuilder<>(keyMapper);
    final int NUM_IDS = 20;
    Long[] requestIds = generateIds(NUM_IDS);
    Collection<ScatterGatherBuilder.KVRequestInfo<Long, Greeting>> scatterGatherRequests = buildScatterGatherGetKVRequests(sg, requestIds);
}

Example 4 with KeyMapper

use of com.linkedin.d2.balancer.KeyMapper in project rest.li by linkedin.

the class TestScatterGather method testScatterGatherLoadBalancerIntegration.

@Test(dataProvider = "requestBuilderDataProvider")
public static void testScatterGatherLoadBalancerIntegration(RootBuilderWrapper<Long, Greeting> builders) throws Exception {
    SimpleLoadBalancer loadBalancer = MockLBFactory.createLoadBalancer();
    KeyMapper keyMapper = new ConsistentHashKeyMapper(loadBalancer, new TestPartitionInfoProvider());
    try {
        keyMapper.mapKeysV2(URI.create("http://badurischeme/"), new HashSet<String>());
        Assert.fail("keyMapper should reject non-D2 URI scheme");
    } catch (IllegalArgumentException e) {
    // expected
    }
    ScatterGatherBuilder<Greeting> sg = new ScatterGatherBuilder<>(keyMapper);
    final int NUM_IDS = 20;
    Long[] requestIds = generateIds(NUM_IDS);
    Collection<ScatterGatherBuilder.RequestInfo<Greeting>> scatterGatherRequests = buildScatterGatherGetRequests(sg, requestIds);
}

Example 5 with KeyMapper

use of com.linkedin.d2.balancer.KeyMapper in project rest.li by linkedin.

the class SimpleLoadBalancerTest method testLoadBalancerWithPartitionsSmoke.

// load balancer working with partitioned cluster
@Test(groups = { "small", "back-end" })
public void testLoadBalancerWithPartitionsSmoke() throws URISyntaxException, ServiceUnavailableException, InterruptedException, ExecutionException {
    for (int tryAgain = 0; tryAgain < 12; ++tryAgain) {
        Map<String, LoadBalancerStrategyFactory<? extends LoadBalancerStrategy>> loadBalancerStrategyFactories = new HashMap<>();
        Map<String, TransportClientFactory> clientFactories = new HashMap<>();
        List<String> prioritizedSchemes = new ArrayList<>();
        MockStore<ServiceProperties> serviceRegistry = new MockStore<>();
        MockStore<ClusterProperties> clusterRegistry = new MockStore<>();
        MockStore<UriProperties> uriRegistry = new MockStore<>();
        ScheduledExecutorService executorService = Executors.newSingleThreadScheduledExecutor();
        loadBalancerStrategyFactories.put("degrader", new DegraderLoadBalancerStrategyFactoryV3());
        clientFactories.put(PropertyKeys.HTTP_SCHEME, new DoNothingClientFactory());
        SimpleLoadBalancerState state = new SimpleLoadBalancerState(executorService, uriRegistry, clusterRegistry, serviceRegistry, clientFactories, loadBalancerStrategyFactories);
        SimpleLoadBalancer loadBalancer = new SimpleLoadBalancer(state, 5, TimeUnit.SECONDS, executorService);
        FutureCallback<None> balancerCallback = new FutureCallback<>();
        loadBalancer.start(balancerCallback);
        balancerCallback.get();
        URI uri1 = URI.create("http://test.qa1.com:1234");
        URI uri2 = URI.create("http://test.qa2.com:2345");
        URI uri3 = URI.create("http://test.qa3.com:6789");
        Map<URI, Double> uris = new HashMap<>();
        uris.put(uri1, 1d);
        uris.put(uri2, 1d);
        uris.put(uri3, 1d);
        Map<URI, Map<Integer, PartitionData>> partitionDesc = new HashMap<>();
        Map<Integer, PartitionData> server1 = new HashMap<>();
        server1.put(0, new PartitionData(1d));
        server1.put(1, new PartitionData(1d));
        Map<Integer, PartitionData> server2 = new HashMap<>();
        server2.put(0, new PartitionData(1d));
        Map<Integer, PartitionData> server3 = new HashMap<>();
        server3.put(1, new PartitionData(1d));
        partitionDesc.put(uri1, server1);
        partitionDesc.put(uri2, server2);
        partitionDesc.put(uri3, server3);
        prioritizedSchemes.add(PropertyKeys.HTTP_SCHEME);
        int partitionMethod = tryAgain % 4;
        switch(partitionMethod) {
            case 0:
                clusterRegistry.put("cluster-1", new ClusterProperties("cluster-1", null, new HashMap<>(), new HashSet<>(), new RangeBasedPartitionProperties("id=(\\d+)", 0, 50, 2)));
                break;
            case 1:
                clusterRegistry.put("cluster-1", new ClusterProperties("cluster-1", null, new HashMap<>(), new HashSet<>(), new HashBasedPartitionProperties("id=(\\d+)", 2, HashBasedPartitionProperties.HashAlgorithm.valueOf("MODULO"))));
                break;
            case 2:
                clusterRegistry.put("cluster-1", new ClusterProperties("cluster-1", null, new HashMap<>(), new HashSet<>(), new HashBasedPartitionProperties("id=(\\d+)", 2, HashBasedPartitionProperties.HashAlgorithm.valueOf("MD5"))));
                break;
            case 3:
                // test getRings with gap. here, no server serves partition 2
                clusterRegistry.put("cluster-1", new ClusterProperties("cluster-1", null, new HashMap<>(), new HashSet<>(), new RangeBasedPartitionProperties("id=(\\d+)", 0, 50, 4)));
                server3.put(3, new PartitionData(1d));
                partitionDesc.put(uri3, server3);
                break;
            default:
                break;
        }
        serviceRegistry.put("foo", new ServiceProperties("foo", "cluster-1", "/foo", Arrays.asList("degrader"), Collections.singletonMap(PropertyKeys.HTTP_LB_CONSISTENT_HASH_ALGORITHM, "pointBased"), null, null, prioritizedSchemes, null));
        uriRegistry.put("cluster-1", new UriProperties("cluster-1", partitionDesc));
        if (partitionMethod == 3) {
            Map<Integer, Ring<URI>> ringMap = loadBalancer.getRings(URI.create("d2://foo"));
            assertEquals(ringMap.size(), 4);
            // the ring for partition 2 should be empty
            assertEquals(ringMap.get(2).toString(), new ConsistentHashRing<>(Collections.emptyList()).toString());
            continue;
        }
        URI expectedUri1 = URI.create("http://test.qa1.com:1234/foo");
        URI expectedUri2 = URI.create("http://test.qa2.com:2345/foo");
        URI expectedUri3 = URI.create("http://test.qa3.com:6789/foo");
        Set<URI> expectedUris = new HashSet<>();
        expectedUris.add(expectedUri1);
        expectedUris.add(expectedUri2);
        expectedUris.add(expectedUri3);
        for (int i = 0; i < 1000; ++i) {
            int ii = i % 100;
            RewriteLoadBalancerClient client = (RewriteLoadBalancerClient) loadBalancer.getClient(new URIRequest("d2://foo/id=" + ii), new RequestContext());
            String clientUri = client.getUri().toString();
            HashFunction<String[]> hashFunction = null;
            String[] str = new String[1];
            // test KeyMapper target host hint: request is always to target host regardless of what's in d2 URI and whether it's hash-based or range-based partitions
            RequestContext requestContextWithHint = new RequestContext();
            KeyMapper.TargetHostHints.setRequestContextTargetHost(requestContextWithHint, uri1);
            RewriteLoadBalancerClient hintedClient1 = (RewriteLoadBalancerClient) loadBalancer.getClient(new URIRequest("d2://foo/id=" + ii), requestContextWithHint);
            String hintedUri1 = hintedClient1.getUri().toString();
            Assert.assertEquals(hintedUri1, uri1.toString() + "/foo");
            RewriteLoadBalancerClient hintedClient2 = (RewriteLoadBalancerClient) loadBalancer.getClient(new URIRequest("d2://foo/action=purge-all"), requestContextWithHint);
            String hintedUri2 = hintedClient2.getUri().toString();
            Assert.assertEquals(hintedUri2, uri1.toString() + "/foo");
            if (partitionMethod == 2) {
                hashFunction = new MD5Hash();
            }
            for (URI uri : expectedUris) {
                if (clientUri.contains(uri.toString())) {
                    // check if only key belonging to partition 0 gets uri2
                    if (uri.equals(uri2)) {
                        if (partitionMethod == 0) {
                            assertTrue(ii < 50);
                        } else if (partitionMethod == 1) {
                            assertTrue(ii % 2 == 0);
                        } else {
                            str[0] = ii + "";
                            assertTrue(hashFunction.hash(str) % 2 == 0);
                        }
                    }
                    // check if only key belonging to partition 1 gets uri3
                    if (uri.equals(uri3)) {
                        if (partitionMethod == 0) {
                            assertTrue(ii >= 50);
                        } else if (partitionMethod == 1) {
                            assertTrue(ii % 2 == 1);
                        } else {
                            str[0] = ii + "";
                            assertTrue(hashFunction.hash(str) % 2 == 1);
                        }
                    }
                }
            }
        }
        // two rings for two partitions
        Map<Integer, Ring<URI>> ringMap = loadBalancer.getRings(URI.create("d2://foo"));
        assertEquals(ringMap.size(), 2);
        if (partitionMethod != 2) {
            Set<String> keys = new HashSet<>();
            for (int j = 0; j < 50; j++) {
                if (partitionMethod == 0) {
                    keys.add(j + "");
                } else {
                    keys.add(j * 2 + "");
                }
            }
            // if it is range based partition, all keys from 0 ~ 49 belong to partition 0 according to the range definition
            // if it is modulo based partition, all even keys belong to partition 0 because the partition count is 2
            // only from partition 0
            MapKeyResult<Ring<URI>, String> mapKeyResult = loadBalancer.getRings(URI.create("d2://foo"), keys);
            Map<Ring<URI>, Collection<String>> keyToPartition = mapKeyResult.getMapResult();
            assertEquals(keyToPartition.size(), 1);
            for (Ring<URI> ring : keyToPartition.keySet()) {
                assertEquals(ring, ringMap.get(0));
            }
            // now also from partition 1
            keys.add("51");
            mapKeyResult = loadBalancer.getRings(URI.create("d2://foo"), keys);
            assertEquals(mapKeyResult.getMapResult().size(), 2);
            assertEquals(mapKeyResult.getUnmappedKeys().size(), 0);
            // now only from partition 1
            keys.clear();
            keys.add("99");
            mapKeyResult = loadBalancer.getRings(URI.create("d2://foo"), keys);
            keyToPartition = mapKeyResult.getMapResult();
            assertEquals(keyToPartition.size(), 1);
            assertEquals(mapKeyResult.getUnmappedKeys().size(), 0);
            for (Ring<URI> ring : keyToPartition.keySet()) {
                assertEquals(ring, ringMap.get(1));
            }
            keys.add("100");
            mapKeyResult = loadBalancer.getRings(URI.create("d2://foo"), keys);
            if (partitionMethod == 0) {
                // key out of range
                Collection<MapKeyResult.UnmappedKey<String>> unmappedKeys = mapKeyResult.getUnmappedKeys();
                assertEquals(unmappedKeys.size(), 1);
            }
            try {
                loadBalancer.getClient(new URIRequest("d2://foo/id=100"), new RequestContext());
                if (partitionMethod == 0) {
                    // key out of range
                    fail("Should throw ServiceUnavailableException caused by PartitionAccessException");
                }
            } catch (ServiceUnavailableException e) {
            }
        }
        final CountDownLatch latch = new CountDownLatch(1);
        PropertyEventShutdownCallback callback = new PropertyEventShutdownCallback() {

            @Override
            public void done() {
                latch.countDown();
            }
        };
        state.shutdown(callback);
        if (!latch.await(60, TimeUnit.SECONDS)) {
            fail("unable to shutdown state");
        }
        executorService.shutdownNow();
        assertTrue(executorService.isShutdown(), "ExecutorService should have shut down!");
    }
}