专栏首页码匠的流水账聊聊nacos RaftCore的signalPublish

聊聊nacos RaftCore的signalPublish

本文主要研究一下nacos RaftCore的signalPublish

RaftCore

nacos-1.1.3/naming/src/main/java/com/alibaba/nacos/naming/consistency/persistent/raft/RaftCore.java

@Component
public class RaftCore {

    public static final String API_VOTE = UtilsAndCommons.NACOS_NAMING_CONTEXT + "/raft/vote";

    public static final String API_BEAT = UtilsAndCommons.NACOS_NAMING_CONTEXT + "/raft/beat";

    public static final String API_PUB = UtilsAndCommons.NACOS_NAMING_CONTEXT + "/raft/datum";

    public static final String API_DEL = UtilsAndCommons.NACOS_NAMING_CONTEXT + "/raft/datum";

    public static final String API_GET = UtilsAndCommons.NACOS_NAMING_CONTEXT + "/raft/datum";

    public static final String API_ON_PUB = UtilsAndCommons.NACOS_NAMING_CONTEXT + "/raft/datum/commit";

    public static final String API_ON_DEL = UtilsAndCommons.NACOS_NAMING_CONTEXT + "/raft/datum/commit";

    public static final String API_GET_PEER = UtilsAndCommons.NACOS_NAMING_CONTEXT + "/raft/peer";

    private ScheduledExecutorService executor = new ScheduledThreadPoolExecutor(1, new ThreadFactory() {
        @Override
        public Thread newThread(Runnable r) {
            Thread t = new Thread(r);

            t.setDaemon(true);
            t.setName("com.alibaba.nacos.naming.raft.notifier");

            return t;
        }
    });

    public static final Lock OPERATE_LOCK = new ReentrantLock();

    public static final int PUBLISH_TERM_INCREASE_COUNT = 100;

    private volatile Map<String, List<RecordListener>> listeners = new ConcurrentHashMap<>();

    private volatile ConcurrentMap<String, Datum> datums = new ConcurrentHashMap<>();

    @Autowired
    private RaftPeerSet peers;

    @Autowired
    private SwitchDomain switchDomain;

    @Autowired
    private GlobalConfig globalConfig;

    @Autowired
    private RaftProxy raftProxy;

    @Autowired
    private RaftStore raftStore;

    public volatile Notifier notifier = new Notifier();

    private boolean initialized = false;

    @PostConstruct
    public void init() throws Exception {

        Loggers.RAFT.info("initializing Raft sub-system");

        executor.submit(notifier);

        long start = System.currentTimeMillis();

        raftStore.loadDatums(notifier, datums);

        setTerm(NumberUtils.toLong(raftStore.loadMeta().getProperty("term"), 0L));

        Loggers.RAFT.info("cache loaded, datum count: {}, current term: {}", datums.size(), peers.getTerm());

        while (true) {
            if (notifier.tasks.size() <= 0) {
                break;
            }
            Thread.sleep(1000L);
        }

        initialized = true;

        Loggers.RAFT.info("finish to load data from disk, cost: {} ms.", (System.currentTimeMillis() - start));

        GlobalExecutor.registerMasterElection(new MasterElection());
        GlobalExecutor.registerHeartbeat(new HeartBeat());

        Loggers.RAFT.info("timer started: leader timeout ms: {}, heart-beat timeout ms: {}",
            GlobalExecutor.LEADER_TIMEOUT_MS, GlobalExecutor.HEARTBEAT_INTERVAL_MS);
    }

    public Map<String, List<RecordListener>> getListeners() {
        return listeners;
    }

    public void signalPublish(String key, Record value) throws Exception {

        if (!isLeader()) {
            JSONObject params = new JSONObject();
            params.put("key", key);
            params.put("value", value);
            Map<String, String> parameters = new HashMap<>(1);
            parameters.put("key", key);

            raftProxy.proxyPostLarge(getLeader().ip, API_PUB, params.toJSONString(), parameters);
            return;
        }

        try {
            OPERATE_LOCK.lock();
            long start = System.currentTimeMillis();
            final Datum datum = new Datum();
            datum.key = key;
            datum.value = value;
            if (getDatum(key) == null) {
                datum.timestamp.set(1L);
            } else {
                datum.timestamp.set(getDatum(key).timestamp.incrementAndGet());
            }

            JSONObject json = new JSONObject();
            json.put("datum", datum);
            json.put("source", peers.local());

            onPublish(datum, peers.local());

            final String content = JSON.toJSONString(json);

            final CountDownLatch latch = new CountDownLatch(peers.majorityCount());
            for (final String server : peers.allServersIncludeMyself()) {
                if (isLeader(server)) {
                    latch.countDown();
                    continue;
                }
                final String url = buildURL(server, API_ON_PUB);
                HttpClient.asyncHttpPostLarge(url, Arrays.asList("key=" + key), content, new AsyncCompletionHandler<Integer>() {
                    @Override
                    public Integer onCompleted(Response response) throws Exception {
                        if (response.getStatusCode() != HttpURLConnection.HTTP_OK) {
                            Loggers.RAFT.warn("[RAFT] failed to publish data to peer, datumId={}, peer={}, http code={}",
                                datum.key, server, response.getStatusCode());
                            return 1;
                        }
                        latch.countDown();
                        return 0;
                    }

                    @Override
                    public STATE onContentWriteCompleted() {
                        return STATE.CONTINUE;
                    }
                });

            }

            if (!latch.await(UtilsAndCommons.RAFT_PUBLISH_TIMEOUT, TimeUnit.MILLISECONDS)) {
                // only majority servers return success can we consider this update success
                Loggers.RAFT.error("data publish failed, caused failed to notify majority, key={}", key);
                throw new IllegalStateException("data publish failed, caused failed to notify majority, key=" + key);
            }

            long end = System.currentTimeMillis();
            Loggers.RAFT.info("signalPublish cost {} ms, key: {}", (end - start), key);
        } finally {
            OPERATE_LOCK.unlock();
        }
    }

    //......
}
  • signalPublish方法判断当前节点是否是leader,如果不是则转发publish到leader节点的/v1/ns/raft/datum接口
  • 如果是leader则构造datum以及peers.majorityCount()大小的CountDownLatch,然后遍历peers.allServersIncludeMyself(),对于leader节点直接latch.countDown(),对于非leader节点则发送异步请求,请求/v1/ns/raft/datum/commit接口,在onCompleted的时候,如果请求成功执行latch.countDown()
  • 最后对于CountDownLatch未能在RAFT_PUBLISH_TIMEOUT返回的,抛出IllegalStateException

RaftController

nacos-1.1.3/naming/src/main/java/com/alibaba/nacos/naming/controllers/RaftController.java

@RestController
@RequestMapping({UtilsAndCommons.NACOS_NAMING_CONTEXT + "/raft",
    UtilsAndCommons.NACOS_SERVER_CONTEXT + UtilsAndCommons.NACOS_NAMING_CONTEXT + "/raft"})
public class RaftController {

    @Autowired
    private RaftConsistencyServiceImpl raftConsistencyService;

    @Autowired
    private ServiceManager serviceManager;

    @Autowired
    private RaftCore raftCore;

    //......

    @NeedAuth
    @RequestMapping(value = "/datum/commit", method = RequestMethod.POST)
    public String onPublish(HttpServletRequest request, HttpServletResponse response) throws Exception {

        response.setHeader("Content-Type", "application/json; charset=" + getAcceptEncoding(request));
        response.setHeader("Cache-Control", "no-cache");
        response.setHeader("Content-Encode", "gzip");

        String entity = IOUtils.toString(request.getInputStream(), "UTF-8");
        String value = URLDecoder.decode(entity, "UTF-8");
        JSONObject jsonObject = JSON.parseObject(value);
        String key = "key";

        RaftPeer source = JSON.parseObject(jsonObject.getString("source"), RaftPeer.class);
        JSONObject datumJson = jsonObject.getJSONObject("datum");

        Datum datum = null;
        if (KeyBuilder.matchInstanceListKey(datumJson.getString(key))) {
            datum = JSON.parseObject(jsonObject.getString("datum"), new TypeReference<Datum<Instances>>() {
            });
        } else if (KeyBuilder.matchSwitchKey(datumJson.getString(key))) {
            datum = JSON.parseObject(jsonObject.getString("datum"), new TypeReference<Datum<SwitchDomain>>() {
            });
        } else if (KeyBuilder.matchServiceMetaKey(datumJson.getString(key))) {
            datum = JSON.parseObject(jsonObject.getString("datum"), new TypeReference<Datum<Service>>() {
            });
        }

        raftConsistencyService.onPut(datum, source);
        return "ok";
    }

    //......
}
  • onPublish方法主要是执行raftConsistencyService.onPut(datum, source)

RaftConsistencyServiceImpl

nacos-1.1.3/naming/src/main/java/com/alibaba/nacos/naming/consistency/persistent/raft/RaftConsistencyServiceImpl.java

@Service
public class RaftConsistencyServiceImpl implements PersistentConsistencyService {

    @Autowired
    private RaftCore raftCore;

    @Autowired
    private RaftPeerSet peers;

    @Autowired
    private SwitchDomain switchDomain;

    //......

    public void onPut(Datum datum, RaftPeer source) throws NacosException {
        try {
            raftCore.onPublish(datum, source);
        } catch (Exception e) {
            Loggers.RAFT.error("Raft onPut failed.", e);
            throw new NacosException(NacosException.SERVER_ERROR, "Raft onPut failed, datum:" + datum + ", source: " + source, e);
        }
    }

    //......
}
  • onPut方法执行的是raftCore.onPublish(datum, source)

RaftCore

nacos-1.1.3/naming/src/main/java/com/alibaba/nacos/naming/consistency/persistent/raft/RaftCore.java

@Component
public class RaftCore {

    public static final String API_VOTE = UtilsAndCommons.NACOS_NAMING_CONTEXT + "/raft/vote";

    public static final String API_BEAT = UtilsAndCommons.NACOS_NAMING_CONTEXT + "/raft/beat";

    public static final String API_PUB = UtilsAndCommons.NACOS_NAMING_CONTEXT + "/raft/datum";

    public static final String API_DEL = UtilsAndCommons.NACOS_NAMING_CONTEXT + "/raft/datum";

    public static final String API_GET = UtilsAndCommons.NACOS_NAMING_CONTEXT + "/raft/datum";

    public static final String API_ON_PUB = UtilsAndCommons.NACOS_NAMING_CONTEXT + "/raft/datum/commit";

    public static final String API_ON_DEL = UtilsAndCommons.NACOS_NAMING_CONTEXT + "/raft/datum/commit";

    public static final String API_GET_PEER = UtilsAndCommons.NACOS_NAMING_CONTEXT + "/raft/peer";

    private ScheduledExecutorService executor = new ScheduledThreadPoolExecutor(1, new ThreadFactory() {
        @Override
        public Thread newThread(Runnable r) {
            Thread t = new Thread(r);

            t.setDaemon(true);
            t.setName("com.alibaba.nacos.naming.raft.notifier");

            return t;
        }
    });

    public static final Lock OPERATE_LOCK = new ReentrantLock();

    public static final int PUBLISH_TERM_INCREASE_COUNT = 100;

    private volatile Map<String, List<RecordListener>> listeners = new ConcurrentHashMap<>();

    private volatile ConcurrentMap<String, Datum> datums = new ConcurrentHashMap<>();

    @Autowired
    private RaftPeerSet peers;

    @Autowired
    private SwitchDomain switchDomain;

    @Autowired
    private GlobalConfig globalConfig;

    @Autowired
    private RaftProxy raftProxy;

    @Autowired
    private RaftStore raftStore;

    public volatile Notifier notifier = new Notifier();

    private boolean initialized = false;

    //......

    public void onPublish(Datum datum, RaftPeer source) throws Exception {
        RaftPeer local = peers.local();
        if (datum.value == null) {
            Loggers.RAFT.warn("received empty datum");
            throw new IllegalStateException("received empty datum");
        }

        if (!peers.isLeader(source.ip)) {
            Loggers.RAFT.warn("peer {} tried to publish data but wasn't leader, leader: {}",
                JSON.toJSONString(source), JSON.toJSONString(getLeader()));
            throw new IllegalStateException("peer(" + source.ip + ") tried to publish " +
                "data but wasn't leader");
        }

        if (source.term.get() < local.term.get()) {
            Loggers.RAFT.warn("out of date publish, pub-term: {}, cur-term: {}",
                JSON.toJSONString(source), JSON.toJSONString(local));
            throw new IllegalStateException("out of date publish, pub-term:"
                + source.term.get() + ", cur-term: " + local.term.get());
        }

        local.resetLeaderDue();

        // if data should be persistent, usually this is always true:
        if (KeyBuilder.matchPersistentKey(datum.key)) {
            raftStore.write(datum);
        }

        datums.put(datum.key, datum);

        if (isLeader()) {
            local.term.addAndGet(PUBLISH_TERM_INCREASE_COUNT);
        } else {
            if (local.term.get() + PUBLISH_TERM_INCREASE_COUNT > source.term.get()) {
                //set leader term:
                getLeader().term.set(source.term.get());
                local.term.set(getLeader().term.get());
            } else {
                local.term.addAndGet(PUBLISH_TERM_INCREASE_COUNT);
            }
        }
        raftStore.updateTerm(local.term.get());

        notifier.addTask(datum.key, ApplyAction.CHANGE);

        Loggers.RAFT.info("data added/updated, key={}, term={}", datum.key, local.term);
    }

    //......
}
  • onPublish方法首先判断请求的节点是否是leader,不是则抛出IllegalStateException;对于source.term小于local.term的抛出IllegalStateException
  • 之后执行local.resetLeaderDue(),以及raftStore.write(datum),datums.put(datum.key, datum);对于leader节点执行local.term.addAndGet(PUBLISH_TERM_INCREASE_COUNT),非leader节点则更新leader term以及local.term
  • 最后执行raftStore.updateTerm(local.term.get())以及notifier.addTask(datum.key, ApplyAction.CHANGE)

小结

  • signalPublish方法判断当前节点是否是leader,如果不是则转发publish到leader节点的/v1/ns/raft/datum接口
  • 如果是leader则构造datum以及peers.majorityCount()大小的CountDownLatch,然后遍历peers.allServersIncludeMyself(),对于leader节点直接latch.countDown(),对于非leader节点则发送异步请求,请求/v1/ns/raft/datum/commit接口,在onCompleted的时候,如果请求成功执行latch.countDown()
  • 最后对于CountDownLatch未能在RAFT_PUBLISH_TIMEOUT返回的,抛出IllegalStateException

doc

  • RaftCore

本文分享自微信公众号 - 码匠的流水账(geek_luandun)

原文出处及转载信息见文内详细说明,如有侵权,请联系 yunjia_community@tencent.com 删除。

原始发表时间:2019-10-25

本文参与腾讯云自媒体分享计划,欢迎正在阅读的你也加入,一起分享。

我来说两句

0 条评论
登录 后参与评论

相关文章

  • JavaSE笔记

    (2)一个.java源文件中可以声明多个类,但是只能有一个public修饰的类,文件名要和public修饰的类名保持一致;

    阮键
  • Python | Python学习之多线程详解

    python的threading模块是对thread做了一些包装的,可以更加方便的被使用,线程的方法和进程的基本相似,这里就不多赘述,下面举几个栗子:

    咸鱼学Python
  • 460道Java后端面试高频题答案版【模块十:SpringMVC】

    对于 SpringMVC 并没有太多的学习经验分享给大家,因为我是通过某培训机构的视频学习的 SpringMVC。我个人认为 SpringMVC 的高频面试点有...

    乔戈里
  • JAVA基础复习(重点)

    (2)一个.java源文件中可以声明多个类,但是只能有一个public修饰的类,文件名要和public修饰的类名保持一致;

    阮键
  • leetcode478. Generate Random Point in a Circle

    假设现在已知圆的圆心的x和y坐标,以及该圆的半径radius。要求写一个随机点生成器,要求该生成器生成的点必须在圆内,且每一个点被生成的概率为相等的。规定圆周上...

    眯眯眼的猫头鹰
  • Netty整理(三) 顶

    JDK ByteBuffer 共用读写索引,每次读写操作都需要Flip() 扩容麻烦,而且扩...

    算法之名
  • 怎样成为一个优秀的架构师?

    架构师是一个既能掌控整体又能洞悉局部瓶颈并依据具体的业务场景给出解决方案的团队领导型人物。看似完美的“人格模型”背后,是艰辛的探索。

    一个会写诗的程序员
  • zookeeper特性与节点说明

    这些问题可以统一归纳为多节点协调问题,如果靠节点自身进行协调这是非常不可靠的,性能上也不可取。必须由一个独立的服务做协调工作,它必须可靠,而且保证性能。

    程序员小强
  • 2019 金九银十多家BAT大厂Android面试真题锦集干货整理

    又到了金九银十的面试季,自己也不得不参与到这场战役中来,其实是从去年底就开始看,android的好机会确实不太多,但也还好,3年+的android开发经历还是有...

    Android技术干货分享
  • 学生怎么入门Android?这四点很重要!

    既然大家已决定学Android,相信你对Android已有些了解,知道应该学习什么语言,这里我就不细说了,Android首先要学的是Java se,也就是JAV...

    Android技术干货分享

扫码关注云+社区

领取腾讯云代金券