RocketMQ consumer 注册过程

2020-05-03 本文已影响0人晴天哥_王志

系列

开篇

这个系列的主要目的是介绍RocketMq consumer的原理和用法，在这个系列当中会介绍 consumer的启动流程、consumer Rebalance的过程、consumer注册过程、consumer 并行消费过程、consumer 有序消费过程。
这篇文章介绍consumer注册过程，分析consumer注册到broker的过程。

consumer 注册流程

consumer的注册流程核心包括：1、consumer通知broker注册；2、broker通知consumer进行rebalance。

consumer 注册源码分析

public class DefaultMQPushConsumerImpl implements MQConsumerInner {

    public synchronized void start() throws MQClientException {
        switch (this.serviceState) {
            case CREATE_JUST:
               
                this.serviceState = ServiceState.START_FAILED;

                this.checkConfig();
                // 内部会生成%RETRY%consume_group重试队列
                this.copySubscription();

                if (this.defaultMQPushConsumer.getMessageModel() == MessageModel.CLUSTERING) {
                    this.defaultMQPushConsumer.changeInstanceNameToPID();
                }

                this.mQClientFactory = MQClientManager.getInstance().getOrCreateMQClientInstance(this.defaultMQPushConsumer, this.rpcHook);

                this.rebalanceImpl.setConsumerGroup(this.defaultMQPushConsumer.getConsumerGroup());
                this.rebalanceImpl.setMessageModel(this.defaultMQPushConsumer.getMessageModel());
                this.rebalanceImpl.setAllocateMessageQueueStrategy(this.defaultMQPushConsumer.getAllocateMessageQueueStrategy());
                this.rebalanceImpl.setmQClientFactory(this.mQClientFactory);

                this.pullAPIWrapper = new PullAPIWrapper(
                    mQClientFactory,
                    this.defaultMQPushConsumer.getConsumerGroup(), isUnitMode());
                this.pullAPIWrapper.registerFilterMessageHook(filterMessageHookList);

                if (this.defaultMQPushConsumer.getOffsetStore() != null) {
                    this.offsetStore = this.defaultMQPushConsumer.getOffsetStore();
                } else {
                    switch (this.defaultMQPushConsumer.getMessageModel()) {
                        case BROADCASTING:
                            this.offsetStore = new LocalFileOffsetStore(this.mQClientFactory, this.defaultMQPushConsumer.getConsumerGroup());
                            break;
                        case CLUSTERING:
                            this.offsetStore = new RemoteBrokerOffsetStore(this.mQClientFactory, this.defaultMQPushConsumer.getConsumerGroup());
                            break;
                        default:
                            break;
                    }
                    this.defaultMQPushConsumer.setOffsetStore(this.offsetStore);
                }
                this.offsetStore.load();

                if (this.getMessageListenerInner() instanceof MessageListenerOrderly) {
                    this.consumeOrderly = true;
                    this.consumeMessageService =
                        new ConsumeMessageOrderlyService(this, (MessageListenerOrderly) this.getMessageListenerInner());
                } else if (this.getMessageListenerInner() instanceof MessageListenerConcurrently) {
                    this.consumeOrderly = false;
                    this.consumeMessageService =
                        new ConsumeMessageConcurrentlyService(this, (MessageListenerConcurrently) this.getMessageListenerInner());
                }

                this.consumeMessageService.start();
                
                // 注册consumer group 和 对应的DefaultMQPushConsumerImpl到MQClientInstance#consumerTable当中
                boolean registerOK = mQClientFactory.registerConsumer(this.defaultMQPushConsumer.getConsumerGroup(), this);
                if (!registerOK) {
                    this.serviceState = ServiceState.CREATE_JUST;
                    this.consumeMessageService.shutdown();
                    throw new MQClientException("The consumer group[" + this.defaultMQPushConsumer.getConsumerGroup()
                        + "] has been created before, specify another name please." + FAQUrl.suggestTodo(FAQUrl.GROUP_NAME_DUPLICATE_URL),
                        null);
                }

                mQClientFactory.start();
                log.info("the consumer [{}] start OK.", this.defaultMQPushConsumer.getConsumerGroup());
                this.serviceState = ServiceState.RUNNING;
                break;
            case RUNNING:
            case START_FAILED:
            case SHUTDOWN_ALREADY:
                throw new MQClientException("The PushConsumer service state not OK, maybe started once, "
                    + this.serviceState
                    + FAQUrl.suggestTodo(FAQUrl.CLIENT_SERVICE_NOT_OK),
                    null);
            default:
                break;
        }

        this.updateTopicSubscribeInfoWhenSubscriptionChanged();
        this.mQClientFactory.checkClientInBroker();
        // 通过sendHeartbeatToAllBrokerWithLock通知所有的broker
        this.mQClientFactory.sendHeartbeatToAllBrokerWithLock();
        this.mQClientFactory.rebalanceImmediately();
    }


    private void copySubscription() throws MQClientException {
        try {
            Map<String, String> sub = this.defaultMQPushConsumer.getSubscription();
            if (sub != null) {
                for (final Map.Entry<String, String> entry : sub.entrySet()) {
                    final String topic = entry.getKey();
                    final String subString = entry.getValue();
                    SubscriptionData subscriptionData = FilterAPI.buildSubscriptionData(this.defaultMQPushConsumer.getConsumerGroup(),
                        topic, subString);
                    this.rebalanceImpl.getSubscriptionInner().put(topic, subscriptionData);
                }
            }

            if (null == this.messageListenerInner) {
                this.messageListenerInner = this.defaultMQPushConsumer.getMessageListener();
            }
            // 针对CLUSTERING模式会生成retryTopic对应的订阅SubscriptionData
            switch (this.defaultMQPushConsumer.getMessageModel()) {
                case BROADCASTING:
                    break;
                case CLUSTERING:
                    final String retryTopic = MixAll.getRetryTopic(this.defaultMQPushConsumer.getConsumerGroup());
                    SubscriptionData subscriptionData = FilterAPI.buildSubscriptionData(this.defaultMQPushConsumer.getConsumerGroup(),
                        retryTopic, SubscriptionData.SUB_ALL);
                    this.rebalanceImpl.getSubscriptionInner().put(retryTopic, subscriptionData);
                    break;
                default:
                    break;
            }
        } catch (Exception e) {
            throw new MQClientException("subscription exception", e);
        }
    }
}

DefaultMQPushConsumerImpl的启动过程中会注册consumer group和对应的DefaultMQPushConsumerImpl到MQClientInstance#consumerTable中。
通过sendHeartbeatToAllBrokerWithLock将consumer注册信息通知所有的broker。
copySubscription方法内部针对CLUSTERING模式会生成retryTopic对应的订阅SubscriptionData。

MQClientInstance发送心跳注册信息

public class MQClientInstance {

    private final ConcurrentMap<String/* group */, MQProducerInner> producerTable = new ConcurrentHashMap<String, MQProducerInner>();
    private final ConcurrentMap<String/* group */, MQConsumerInner> consumerTable = new ConcurrentHashMap<String, MQConsumerInner>();
    private final ConcurrentMap<String/* group */, MQAdminExtInner> adminExtTable = new ConcurrentHashMap<String, MQAdminExtInner>();
    private final Lock lockHeartbeat = new ReentrantLock();

    public boolean registerConsumer(final String group, final MQConsumerInner consumer) {
        if (null == group || null == consumer) {
            return false;
        }

        MQConsumerInner prev = this.consumerTable.putIfAbsent(group, consumer);
        if (prev != null) {
            log.warn("the consumer group[" + group + "] exist already.");
            return false;
        }

        return true;
    }

    public void sendHeartbeatToAllBrokerWithLock() {
        if (this.lockHeartbeat.tryLock()) {
            try {
                this.sendHeartbeatToAllBroker();
                this.uploadFilterClassSource();
            } catch (final Exception e) {
                log.error("sendHeartbeatToAllBroker exception", e);
            } finally {
                this.lockHeartbeat.unlock();
            }
        } else {
            log.warn("lock heartBeat, but failed.");
        }
    }


    private void sendHeartbeatToAllBroker() {
        // prepareHeartbeatData 负责组装心跳注册信息
        final HeartbeatData heartbeatData = this.prepareHeartbeatData();
        final boolean producerEmpty = heartbeatData.getProducerDataSet().isEmpty();
        final boolean consumerEmpty = heartbeatData.getConsumerDataSet().isEmpty();
        if (producerEmpty && consumerEmpty) {
            log.warn("sending heartbeat, but no consumer and no producer");
            return;
        }

        if (!this.brokerAddrTable.isEmpty()) {
            long times = this.sendHeartbeatTimesTotal.getAndIncrement();
            Iterator<Entry<String, HashMap<Long, String>>> it = this.brokerAddrTable.entrySet().iterator();
            while (it.hasNext()) {
                Entry<String, HashMap<Long, String>> entry = it.next();
                String brokerName = entry.getKey();
                HashMap<Long, String> oneTable = entry.getValue();
                if (oneTable != null) {
                    for (Map.Entry<Long, String> entry1 : oneTable.entrySet()) {
                        Long id = entry1.getKey();
                        String addr = entry1.getValue();
                        if (addr != null) {
                            if (consumerEmpty) {
                                if (id != MixAll.MASTER_ID)
                                    continue;
                            }

                            try {
                                // 发送心跳注册信息
                                int version = this.mQClientAPIImpl.sendHearbeat(addr, heartbeatData, 3000);

                                if (!this.brokerVersionTable.containsKey(brokerName)) {
                                    this.brokerVersionTable.put(brokerName, new HashMap<String, Integer>(4));
                                }
                                this.brokerVersionTable.get(brokerName).put(addr, version);

                            } catch (Exception e) {

                            }
                        }
                    }
                }
            }
        }
    }


    private HeartbeatData prepareHeartbeatData() {
        HeartbeatData heartbeatData = new HeartbeatData();

        // clientID
        heartbeatData.setClientID(this.clientId);

        // Consumer
        for (Map.Entry<String, MQConsumerInner> entry : this.consumerTable.entrySet()) {
            MQConsumerInner impl = entry.getValue();
            if (impl != null) {
                ConsumerData consumerData = new ConsumerData();
                consumerData.setGroupName(impl.groupName());
                consumerData.setConsumeType(impl.consumeType());
                consumerData.setMessageModel(impl.messageModel());
                consumerData.setConsumeFromWhere(impl.consumeFromWhere());
                consumerData.getSubscriptionDataSet().addAll(impl.subscriptions());
                consumerData.setUnitMode(impl.isUnitMode());

                heartbeatData.getConsumerDataSet().add(consumerData);
            }
        }

        // Producer
        for (Map.Entry<String/* group */, MQProducerInner> entry : this.producerTable.entrySet()) {
            MQProducerInner impl = entry.getValue();
            if (impl != null) {
                ProducerData producerData = new ProducerData();
                producerData.setGroupName(entry.getKey());

                heartbeatData.getProducerDataSet().add(producerData);
            }
        }

        return heartbeatData;
    }
}

MQClientInstance发送心跳信息包括组装信息和发送信息两个步骤。
prepareHeartbeatData 负责组装心跳注册信息。
sendHeartbeatToAllBroker负责将心跳注册信息发送给所有的broker信息。

public class MQClientAPIImpl {

    public int sendHearbeat(
        final String addr,
        final HeartbeatData heartbeatData,
        final long timeoutMillis
    ) throws RemotingException, MQBrokerException, InterruptedException {
        RemotingCommand request = RemotingCommand.createRequestCommand(RequestCode.HEART_BEAT, null);
        request.setLanguage(clientConfig.getLanguage());
        request.setBody(heartbeatData.encode());
        RemotingCommand response = this.remotingClient.invokeSync(addr, request, timeoutMillis);
        assert response != null;
        switch (response.getCode()) {
            case ResponseCode.SUCCESS: {
                return response.getVersion();
            }
            default:
                break;
        }

        throw new MQBrokerException(response.getCode(), response.getRemark());
    }
}

MQClientAPIImpl#sendHearbeat负责创建HEART_BEAT类型的RemotingCommand并发送到broker当中。

broker处理心跳信息

public class ClientManageProcessor implements NettyRequestProcessor {

    private static final InternalLogger log = InternalLoggerFactory.getLogger(LoggerName.BROKER_LOGGER_NAME);
    private final BrokerController brokerController;

    public ClientManageProcessor(final BrokerController brokerController) {
        this.brokerController = brokerController;
    }

    @Override
    public RemotingCommand processRequest(ChannelHandlerContext ctx, RemotingCommand request)
        throws RemotingCommandException {
        switch (request.getCode()) {
            case RequestCode.HEART_BEAT:
                return this.heartBeat(ctx, request);
            case RequestCode.UNREGISTER_CLIENT:
                return this.unregisterClient(ctx, request);
            case RequestCode.CHECK_CLIENT_CONFIG:
                return this.checkClientConfig(ctx, request);
            default:
                break;
        }
        return null;
    }


    public RemotingCommand heartBeat(ChannelHandlerContext ctx, RemotingCommand request) {

        RemotingCommand response = RemotingCommand.createResponseCommand(null);
        HeartbeatData heartbeatData = HeartbeatData.decode(request.getBody(), HeartbeatData.class);
        ClientChannelInfo clientChannelInfo = new ClientChannelInfo(
            ctx.channel(),
            heartbeatData.getClientID(),
            request.getLanguage(),
            request.getVersion()
        );

        for (ConsumerData data : heartbeatData.getConsumerDataSet()) {

            SubscriptionGroupConfig subscriptionGroupConfig =
                this.brokerController.getSubscriptionGroupManager().findSubscriptionGroupConfig(
                    data.getGroupName());
            boolean isNotifyConsumerIdsChangedEnable = true;
            if (null != subscriptionGroupConfig) {
                isNotifyConsumerIdsChangedEnable = subscriptionGroupConfig.isNotifyConsumerIdsChangedEnable();
                int topicSysFlag = 0;
                if (data.isUnitMode()) {
                    topicSysFlag = TopicSysFlag.buildSysFlag(false, true);
                }
                // 重试队列是以consumer group为维度的，创建重试队列topic信息
                // topic名的格式为%RETRY%consumer_group
                String newTopic = MixAll.getRetryTopic(data.getGroupName());
                // 创建重试队列对应的topic=%RETRY%consumer_group
this.brokerController.getTopicConfigManager().createTopicInSendMessageBackMethod(
                    newTopic,
                    subscriptionGroupConfig.getRetryQueueNums(),
                    PermName.PERM_WRITE | PermName.PERM_READ, topicSysFlag);
            }

            // 注册consumer信息
            boolean changed = this.brokerController.getConsumerManager().registerConsumer(
                data.getGroupName(),
                clientChannelInfo,
                data.getConsumeType(),
                data.getMessageModel(),
                data.getConsumeFromWhere(),
                data.getSubscriptionDataSet(),
                isNotifyConsumerIdsChangedEnable
            );

            if (changed) {
                log.info("registerConsumer info changed {} {}",
                    data.toString(),
                    RemotingHelper.parseChannelRemoteAddr(ctx.channel())
                );
            }
        }

        // 注册producer信息
        for (ProducerData data : heartbeatData.getProducerDataSet()) {
            this.brokerController.getProducerManager().registerProducer(data.getGroupName(),
                clientChannelInfo);
        }
        response.setCode(ResponseCode.SUCCESS);
        response.setRemark(null);
        return response;
    }
}

broker侧的ClientManageProcessor#heartBeat负责处理心跳注册信息。
1、ClientManageProcessor#heartBeat创建%RETRY%consumer_group的topic信息。
2、ClientManageProcessor#heartBeat通过registerConsumer注册consumer信息。
3、ClientManageProcessor#heartBeat通过registerProducer注册producer信息。

public class ConsumerManager {

    private static final InternalLogger log = InternalLoggerFactory.getLogger(LoggerName.BROKER_LOGGER_NAME);
    private static final long CHANNEL_EXPIRED_TIMEOUT = 1000 * 120;
    private final ConcurrentMap<String/* Group */, ConsumerGroupInfo> consumerTable =
        new ConcurrentHashMap<String, ConsumerGroupInfo>(1024);
    private final ConsumerIdsChangeListener consumerIdsChangeListener;

    public boolean registerConsumer(final String group, final ClientChannelInfo clientChannelInfo,
        ConsumeType consumeType, MessageModel messageModel, ConsumeFromWhere consumeFromWhere,
        final Set<SubscriptionData> subList, boolean isNotifyConsumerIdsChangedEnable) {

        ConsumerGroupInfo consumerGroupInfo = this.consumerTable.get(group);
        if (null == consumerGroupInfo) {
            ConsumerGroupInfo tmp = new ConsumerGroupInfo(group, consumeType, messageModel, consumeFromWhere);
            ConsumerGroupInfo prev = this.consumerTable.putIfAbsent(group, tmp);
            consumerGroupInfo = prev != null ? prev : tmp;
        }

        // 1、更新clientChannelInfo信息
        boolean r1 =
            consumerGroupInfo.updateChannel(clientChannelInfo, consumeType, messageModel,
                consumeFromWhere);

        // 2、更新SubscriptionData的订阅信息
        boolean r2 = consumerGroupInfo.updateSubscription(subList);

        if (r1 || r2) {
            if (isNotifyConsumerIdsChangedEnable) {
              // 3、处理CHANGE事件
              this.consumerIdsChangeListener.handle(ConsumerGroupEvent.CHANGE, group, consumerGroupInfo.getAllChannel());
            }
        }

        // 4、注册REGISTER事件
        this.consumerIdsChangeListener.handle(ConsumerGroupEvent.REGISTER, group, subList);

        return r1 || r2;
    }
}

1、consumerTable变量保存consumer group对应的ConsumerGroupInfo。
2、registerConsumer更新clientChannelInfo信息。
3、registerConsumer更新SubscriptionData的订阅信息
4、registerConsumer处理CHANGE类型事件。
5、registerConsumer处理REGISTER类型事件。

public class ConsumerGroupInfo {

    private final String groupName;
    private final ConcurrentMap<String/* Topic */, SubscriptionData> subscriptionTable =
        new ConcurrentHashMap<String, SubscriptionData>();
    private final ConcurrentMap<Channel, ClientChannelInfo> channelInfoTable =
        new ConcurrentHashMap<Channel, ClientChannelInfo>(16);
    private volatile ConsumeType consumeType;
    private volatile MessageModel messageModel;
    private volatile ConsumeFromWhere consumeFromWhere;
    private volatile long lastUpdateTimestamp = System.currentTimeMillis();

    public boolean updateSubscription(final Set<SubscriptionData> subList) {
        boolean updated = false;

        for (SubscriptionData sub : subList) {
            SubscriptionData old = this.subscriptionTable.get(sub.getTopic());
            if (old == null) {
                SubscriptionData prev = this.subscriptionTable.putIfAbsent(sub.getTopic(), sub);
                if (null == prev) {
                    updated = true;
                    log.info("subscription changed, add new topic, group: {} {}",
                        this.groupName,
                        sub.toString());
                }
            } else if (sub.getSubVersion() > old.getSubVersion()) {
                if (this.consumeType == ConsumeType.CONSUME_PASSIVELY) {
                    log.info("subscription changed, group: {} OLD: {} NEW: {}",
                        this.groupName,
                        old.toString(),
                        sub.toString()
                    );
                }

                this.subscriptionTable.put(sub.getTopic(), sub);
            }
        }

        Iterator<Entry<String, SubscriptionData>> it = this.subscriptionTable.entrySet().iterator();
        while (it.hasNext()) {
            Entry<String, SubscriptionData> next = it.next();
            String oldTopic = next.getKey();

            boolean exist = false;
            for (SubscriptionData sub : subList) {
                if (sub.getTopic().equals(oldTopic)) {
                    exist = true;
                    break;
                }
            }

            if (!exist) {
                log.warn("subscription changed, group: {} remove topic {} {}",
                    this.groupName,
                    oldTopic,
                    next.getValue().toString()
                );

                it.remove();
                updated = true;
            }
        }

        this.lastUpdateTimestamp = System.currentTimeMillis();

        return updated;
    }


    public boolean updateChannel(final ClientChannelInfo infoNew, ConsumeType consumeType,
        MessageModel messageModel, ConsumeFromWhere consumeFromWhere) {
        boolean updated = false;
        this.consumeType = consumeType;
        this.messageModel = messageModel;
        this.consumeFromWhere = consumeFromWhere;

        ClientChannelInfo infoOld = this.channelInfoTable.get(infoNew.getChannel());
        if (null == infoOld) {
            ClientChannelInfo prev = this.channelInfoTable.put(infoNew.getChannel(), infoNew);
            if (null == prev) {
                log.info("new consumer connected, group: {} {} {} channel: {}", this.groupName, consumeType,
                    messageModel, infoNew.toString());
                updated = true;
            }

            infoOld = infoNew;
        } else {
            if (!infoOld.getClientId().equals(infoNew.getClientId())) {
                log.error("[BUG] consumer channel exist in broker, but clientId not equal. GROUP: {} OLD: {} NEW: {} ",
                    this.groupName,
                    infoOld.toString(),
                    infoNew.toString());
                this.channelInfoTable.put(infoNew.getChannel(), infoNew);
            }
        }

        this.lastUpdateTimestamp = System.currentTimeMillis();
        infoOld.setLastUpdateTimestamp(this.lastUpdateTimestamp);

        return updated;
    }
}

subscriptionTable保存的是以topic为维度的订阅信息SubscriptionData。
updateSubscription负责更新指定topic的Subscription信息。
channelInfoTable保存ClientChannelInfo信息。
updateChannel更新ClientChannelInfo信息。

ConsumerIds变更通知

public class DefaultConsumerIdsChangeListener implements ConsumerIdsChangeListener {
    private final BrokerController brokerController;

    public DefaultConsumerIdsChangeListener(BrokerController brokerController) {
        this.brokerController = brokerController;
    }

    @Override
    public void handle(ConsumerGroupEvent event, String group, Object... args) {
        if (event == null) {
            return;
        }
        switch (event) {
            case CHANGE:
                if (args == null || args.length < 1) {
                    return;
                }
                List<Channel> channels = (List<Channel>) args[0];
                if (channels != null && brokerController.getBrokerConfig().isNotifyConsumerIdsChangedEnable()) {
                    for (Channel chl : channels) {
                        this.brokerController.getBroker2Client().notifyConsumerIdsChanged(chl, group);
                    }
                }
                break;
            case UNREGISTER:
                this.brokerController.getConsumerFilterManager().unRegister(group);
                break;
            case REGISTER:
                if (args == null || args.length < 1) {
                    return;
                }
                Collection<SubscriptionData> subscriptionDataList = (Collection<SubscriptionData>) args[0];
                this.brokerController.getConsumerFilterManager().register(group, subscriptionDataList);
                break;
            default:
                throw new RuntimeException("Unknown event " + event);
        }
    }
}


public class Broker2Client {

    public void notifyConsumerIdsChanged(
        final Channel channel,
        final String consumerGroup) {
        if (null == consumerGroup) {
            log.error("notifyConsumerIdsChanged consumerGroup is null");
            return;
        }

        NotifyConsumerIdsChangedRequestHeader requestHeader = new NotifyConsumerIdsChangedRequestHeader();
        requestHeader.setConsumerGroup(consumerGroup);
        RemotingCommand request =
            RemotingCommand.createRequestCommand(RequestCode.NOTIFY_CONSUMER_IDS_CHANGED, requestHeader);

        try {
            this.brokerController.getRemotingServer().invokeOneway(channel, request, 10);
        } catch (Exception e) {
            log.error("notifyConsumerIdsChanged exception, " + consumerGroup, e.getMessage());
        }
    }
}

针对CHANGE事件，brokerController.getBroker2Client().notifyConsumerIdsChanged 通知client进行rebalance。

ClientRemotingProcessor

public class ClientRemotingProcessor implements NettyRequestProcessor {

    public RemotingCommand notifyConsumerIdsChanged(ChannelHandlerContext ctx,
        RemotingCommand request) throws RemotingCommandException {
        try {
            final NotifyConsumerIdsChangedRequestHeader requestHeader =
                (NotifyConsumerIdsChangedRequestHeader) request.decodeCommandCustomHeader(NotifyConsumerIdsChangedRequestHeader.class);
            log.info("receive broker's notification[{}], the consumer group: {} changed, rebalance immediately",
                RemotingHelper.parseChannelRemoteAddr(ctx.channel()),
                requestHeader.getConsumerGroup());

            // 立即开启rebalance
            this.mqClientFactory.rebalanceImmediately();
        } catch (Exception e) {
            log.error("notifyConsumerIdsChanged exception", RemotingHelper.exceptionSimpleDesc(e));
        }
        return null;
    }
}

notifyConsumerIdsChanged会立即开启consumer的rebalance。

RocketMQ consumer 注册过程

系列

开篇

consumer 注册流程

consumer 注册源码分析

MQClientInstance发送心跳注册信息

broker处理心跳信息

ConsumerIds变更通知

ClientRemotingProcessor

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