聊聊puma的DefaultTaskExecutor

序

本文主要研究一下puma的DefaultTaskExecutor

TaskExecutor

puma/puma/src/main/java/com/dianping/puma/taskexecutor/TaskExecutor.java

public interface TaskExecutor extends LifeCycle {

    boolean isStop();

    boolean isMerging();

    void stopUntil(long timestamp);

    void cancelStopUntil();

    void setContext(PumaContext context);

    void initContext();

    PumaContext getContext();

    String getTaskId();

    void setTaskId(String taskId);

    String getTaskName();

    void setTaskName(String taskName);

    String getDefaultBinlogFileName();

    void setDefaultBinlogFileName(String binlogFileName);

    Long getDefaultBinlogPosition();

    void setDefaultBinlogPosition(Long binlogFileName);

    void setInstanceStorageManager(InstanceStorageManager holder);

    List getFileSender();

    DataHandler getDataHandler();

    void resume() throws Exception;

    void pause() throws Exception;

    PumaTaskStateEntity getTaskState();

    void setTaskState(PumaTaskStateEntity taskState);

    void setInstanceTask(InstanceTask instanceTask);

    InstanceTask getInstanceTask();

    TableSet getTableSet();
}

• TaskExecutor继承了LifeCycle，定义了initContext、getContext等方法

AbstractTaskExecutor

puma/puma/src/main/java/com/dianping/puma/taskexecutor/AbstractTaskExecutor.java

@ThreadUnSafe
public abstract class AbstractTaskExecutor implements TaskExecutor {
    private PumaContext context;

    private String taskId;

    private long serverId;

    protected String taskName;

    protected Date beginTime;

    protected TableSet tableSet;

    private String defaultBinlogFileName;

    private Long defaultBinlogPosition;

    protected Parser parser;

    protected DataHandler dataHandler;

    protected Dispatcher dispatcher;

    private volatile boolean stop = true;

    protected InstanceStorageManager instanceStorageManager;

    protected PumaTaskStateEntity state;

    protected InstanceManager instanceManager;

    @Override
    public String getTaskId() {
        return taskId;
    }

    @Override
    public void setTaskId(String taskId) {
        this.taskId = taskId;
    }

    @Override
    public String getTaskName() {
        return taskName;
    }

    @Override
    public void setTaskName(String taskName) {
        this.taskName = taskName;
    }

    /**
     * @param instanceStorageManager
     *           the binlogPositionHolder to set
     */
    public void setInstanceStorageManager(InstanceStorageManager instanceStorageManager) {
        this.instanceStorageManager = instanceStorageManager;
    }

    public void setContext(PumaContext context) {
        this.context = context;
    }

    public PumaContext getContext() {
        return context;
    }

    public String getDefaultBinlogFileName() {
        return defaultBinlogFileName;
    }

    public void setDefaultBinlogFileName(String binlogFileName) {
        this.defaultBinlogFileName = binlogFileName;
    }

    /**
     * @return the defaultBinlogPosition
     */
    public Long getDefaultBinlogPosition() {
        return defaultBinlogPosition;
    }

    /**
     * @param defaultBinlogPosition
     *           the defaultBinlogPosition to set
     */
    public void setDefaultBinlogPosition(Long defaultBinlogPosition) {
        this.defaultBinlogPosition = defaultBinlogPosition;
    }

    /**
     * @param parser
     *           the parser to set
     */
    public void setParser(Parser parser) {
        this.parser = parser;
    }

    /**
     * @param dataHandler
     *           the dataHandler to set
     */
    public void setDataHandler(DataHandler dataHandler) {
        this.dataHandler = dataHandler;
    }

    /**
     * @param dispatcher
     *           the dispatcher to set
     */
    public void setDispatcher(Dispatcher dispatcher) {
        this.dispatcher = dispatcher;
    }

    public long getServerId() {
        return serverId;
    }

    public void setServerId(long serverId) {
        this.serverId = serverId;
    }

    public boolean isStop() {
        return stop;
    }

    protected abstract void doStop() throws Exception;

    protected abstract void doStart() throws Exception;

    @Override
    public void start() {
        try {
            stop = false;

            parser.start();
            dataHandler.start();
            dispatcher.start();
            doStart();
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void stop() {
        try {
            stop = true;

            parser.stop();
            dataHandler.stop();
            dispatcher.stop();

            doStop();
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    public void resume() throws Exception {
        stop = false;
    }

    public void pause() throws Exception {
        stop = true;
    }

    @Override
    public List getFileSender() {
        return dispatcher.getSenders();
    }

    @Override
    public DataHandler getDataHandler() {
        return this.dataHandler;
    }

    public PumaTaskStateEntity getTaskState() {
        return state;
    }

    public void setTaskState(PumaTaskStateEntity state) {
        this.state = state;
    }

    public Date getBeginTime() {
        return beginTime;
    }

    public void setBeginTime(Date beginTime) {
        this.beginTime = beginTime;
    }

    public TableSet getTableSet() {
        return tableSet;
    }

    public void setTableSet(TableSet tableSet) {
        this.tableSet = tableSet;
    }

    public InstanceManager getInstanceManager() {
        return instanceManager;
    }

    public void setInstanceManager(InstanceManager instanceManager) {
        this.instanceManager = instanceManager;
    }
}

• AbstractTaskExecutor声明实现TaskExecutor接口，它定义了context、defaultBinlogFileName、defaultBinlogPosition、parser、dataHandler、dispatcher等属性；其start方法执行parser、dataHandler、dispatcher的start方法及doStart方法；其stop方法执行parser、dataHandler、dispatcher的stop方法及doStop方法

DefaultTaskExecutor

puma/puma/src/main/java/com/dianping/puma/taskexecutor/DefaultTaskExecutor.java

@ThreadUnSafe
public class DefaultTaskExecutor extends AbstractTaskExecutor {

    private static final Logger LOG = LoggerFactory.getLogger(DefaultTaskExecutor.class);

    private SrcDbEntity currentSrcDbEntity;

    private DefaultTableMetaInfoFetcher tableMetaInfoFetcher;

    private String encoding = "utf-8";

    private Socket mysqlSocket;

    private InputStream is;

    private OutputStream os;

    private InstanceTask instanceTask;

    private boolean merging = false;

    private long runUntilTimestamp;

    @Override
    public void doStart() throws Exception {
        Thread.currentThread().setName("DefaultTaskExecutor-" + taskName);
        long failCount = 0;
        merging = false;
        SystemStatusManager.addServer(getTaskName(), "", 0, tableSet);

        do {
            try {
                loadServerId(instanceManager.getUrlByCluster(instanceTask.getInstance()));

                // 读position/file文件
                BinlogInfo binlogInfo = instanceStorageManager.getBinlogInfo(getContext().getPumaServerName());

                if (binlogInfo == null) {
                    this.currentSrcDbEntity = initSrcDbByServerId(-1);
                    if (beginTime != null) {
                        binlogInfo = getBinlogByTimestamp(beginTime.getTime() / 1000);
                    }
                } else {
                    this.currentSrcDbEntity = initSrcDbByServerId(binlogInfo.getServerId());

                    if (binlogInfo.getServerId() != currentSrcDbEntity.getServerId()) {
                        BinlogInfo oldBinlogInfo = binlogInfo;
                        binlogInfo = getBinlogByTimestamp(oldBinlogInfo.getTimestamp() - 60);
                        if (binlogInfo == null) {
                            throw new IOException("Switch Binlog Failed!");
                        } else {
                            Cat.logEvent("BinlogSwitch", taskName, Message.SUCCESS,
                                    oldBinlogInfo.toString() + " -> " + binlogInfo.toString());
                        }
                    }
                }

                updateTableMetaInfoFetcher();
                getContext().setMasterUrl(currentSrcDbEntity.getHost(), currentSrcDbEntity.getPort());

                if (!connect()) {
                    throw new IOException("Connection failed.");
                }

                initConnect();

                initBinlogPosition(binlogInfo);

                if (dumpBinlog()) {
                    processBinlog();
                } else {
                    throw new IOException("Binlog dump failed.");
                }
            } catch (Exception e) {
                if (++failCount % 3 == 0) {
                    this.currentSrcDbEntity = chooseNextSrcDb();
                    updateTableMetaInfoFetcher();
                    failCount = 0;
                }
                String msg = "Exception occurs. taskName: " + getTaskName() + " dbServerId: " + (currentSrcDbEntity == null ? 0 : currentSrcDbEntity.getServerId())
                        + ". Reconnect...";
                LOG.error(msg, e);
                Cat.logError(msg, e);

                Thread.sleep(((failCount % 10) + 1) * 2000);
            }
        } while (!isStop() && !Thread.currentThread().isInterrupted());

    }

    protected void doStop() throws Exception {
        LOG.info("TaskName: " + getTaskName() + ", Stopped.");
        closeTransport();
        SystemStatusManager.deleteServer(getTaskName());
    }

    //......

}

• DefaultTaskExecutor继承了AbstractTaskExecutor，其doStart方法通过instanceStorageManager.getBinlogInfo获取binlogInfo，若为null且beginTime不为null则从getBinlogByTimestamp获取binlogInfo，之后执行updateTableMetaInfoFetcher、connect、initConnect、initBinlogPosition、dumpBinlog、processBinlog方法；其doStop方法主要执行closeTransport、SystemStatusManager.deleteServer(getTaskName())方法

getBinlogByTimestamp

    protected BinlogInfo getBinlogByTimestamp(long time) throws IOException {
        BinlogInfo binlogResult = null;
        Transaction t = Cat.newTransaction("BinlogFindByTime", taskName);

        Cat.logEvent("BinlogFindByTime.Time", String.valueOf(time));

        try {
            if (!connect()) {
                throw new IOException("Connection failed.");
            }
            initConnect();
            List binaryLogs = getBinaryLogs();

            Cat.logEvent("BinlogFindByTime.BinaryLogs", currentSrcDbEntity.toString(), Message.SUCCESS, Joiner.on(",").join(binaryLogs));

            BinlogInfo closestBinlogInfo = null;

            for (int k = binaryLogs.size() - 1; k >= 0; k--) {
                if (binlogResult != null) {
                    break;
                }

                BinlogInfo newBinlogInfo = binaryLogs.get(k);

                Cat.logEvent("BinlogFindByTime.Start", newBinlogInfo.toString());

                getContext().setDBServerId(currentSrcDbEntity.getServerId());
                getContext().setBinlogFileName(newBinlogInfo.getBinlogFile());
                getContext().setBinlogStartPos(4);
                getContext().setMasterUrl(currentSrcDbEntity.getHost(), currentSrcDbEntity.getPort());

                if (!connect()) {
                    throw new IOException("Connection failed.");
                }
                initConnect();

                if (dumpBinlog()) {
                    while (!isStop()) {
                        BinlogPacket binlogPacket = (BinlogPacket) PacketFactory.parsePacket(is,
                                PacketType.BINLOG_PACKET,
                                getContext());

                        if (!binlogPacket.isOk()) {
                            LOG.error("TaskName: " + getTaskName() + ", Binlog packet response error.");
                            throw new IOException("TaskName: " + getTaskName() + ", Binlog packet response error.");
                        } else {
                            BinlogEvent binlogEvent = parser.parse(binlogPacket.getBinlogBuf(), getContext());

                            try {
                                getContext().setNextBinlogPos(binlogEvent.getHeader().getNextPosition());

                                if (binlogEvent.getHeader().getEventType() == BinlogConstants.ROTATE_EVENT) {
                                    if (closestBinlogInfo == null) {
                                        break;
                                    } else {
                                        continue;
                                    }
                                }

                                if (binlogEvent.getHeader().getTimestamp() >= time) {
                                    if (closestBinlogInfo != null) {
                                        binlogResult = closestBinlogInfo;
                                    }
                                    break;
                                }

                                if (binlogEvent.getHeader().getEventType() == BinlogConstants.XID_EVENT
                                        && binlogEvent.getHeader().getTimestamp() < time) {
                                    closestBinlogInfo = new BinlogInfo(
                                            currentSrcDbEntity.getServerId(),
                                            getContext().getBinlogFileName(),
                                            binlogEvent.getHeader().getNextPosition(),
                                            0, binlogEvent.getHeader().getTimestamp());
                                }
                            } finally {
                                if (binlogEvent.getHeader().getEventType() == BinlogConstants.ROTATE_EVENT) {
                                    RotateEvent rotateEvent = (RotateEvent) binlogEvent;
                                    getContext().setBinlogFileName(rotateEvent.getNextBinlogFileName());
                                    getContext().setBinlogStartPos(rotateEvent.getFirstEventPosition());
                                } else {
                                    getContext().setBinlogStartPos(binlogEvent.getHeader().getNextPosition());
                                }
                            }
                        }
                    }
                } else {
                    throw new IOException("Binlog dump failed.");
                }
            }

            Cat.logEvent("BinlogFindByTime.Success", taskName, Message.SUCCESS,
                    time + " -> " + (binlogResult == null ? "null" : binlogResult.toString()));
            t.setStatus(Message.SUCCESS);
            t.complete();
            return binlogResult;
        } catch (IOException e) {
            t.setStatus(e);
            t.complete();
            throw e;
        }
    }

• getBinlogByTimestamp方法先执行connect、initConnect，然后通过getBinaryLogs获取binaryLogs，之后遍历binaryLogs执行dumpBinlog，获取binlogEvent.getHeader().getTimestamp()大于等于指定time的BinlogInfo

connect

    private boolean connect() {
        try {
            closeTransport();
            this.mysqlSocket = new Socket();
            this.mysqlSocket.setTcpNoDelay(false);
            this.mysqlSocket.setKeepAlive(true);
            this.mysqlSocket.connect(new InetSocketAddress(currentSrcDbEntity.getHost(), currentSrcDbEntity.getPort()));
            this.is = new BufferedInputStream(mysqlSocket.getInputStream());
            this.os = new BufferedOutputStream(mysqlSocket.getOutputStream());
            PacketFactory.parsePacket(is, PacketType.CONNECT_PACKET, getContext());

            LOG.info("TaskName: " + getTaskName() + ", Connection db success.");

            return true;
        } catch (Exception e) {
            LOG.error("TaskName: " + getTaskName() + ", Connect failed. Reason: " + e.getMessage());

            return false;
        }
    }

• connect方法先执行closeTransport，然后创建mysqlSocket进行connect

initConnect

    protected void initConnect() throws IOException {
        if (!auth()) {
            throw new IOException("Login failed.");
        }

        if (getContext().isCheckSum()) {
            if (!updateSetting()) {
                throw new IOException("Update setting command failed.");
            }
        }

        if (!queryBinlogFormat()) {
            throw new IOException("Query config binlogformat failed.");
        }
        if (!queryBinlogImage()) {
            throw new IOException("Query config binlog row image failed.");
        }

        if (queryServerId() != currentSrcDbEntity.getServerId()) {
            throw new IOException("Server Id Changed.");
        }
    }

    private boolean auth() {
        try {
            LOG.info("server logining taskName: " + getTaskName() + " host: " + currentSrcDbEntity.getHost() + " port: " + currentSrcDbEntity.getPort() + " username: "
                    + currentSrcDbEntity.getUsername() + " dbServerId: " + currentSrcDbEntity.getServerId());
            AuthenticatePacket authPacket = (AuthenticatePacket) PacketFactory.createCommandPacket(
                    PacketType.AUTHENTICATE_PACKET, getContext());

            authPacket.setPassword(currentSrcDbEntity.getPassword());
            authPacket.setUser(currentSrcDbEntity.getUsername());
            authPacket.buildPacket(getContext());
            authPacket.write(os, getContext());

            OKErrorPacket okErrorPacket = (OKErrorPacket) PacketFactory.parsePacket(is, PacketType.OKERROR_PACKET,
                    getContext());
            boolean isAuth;

            if (okErrorPacket.isOk()) {
                LOG.info("TaskName: " + getTaskName() + ", Server login success.");
                isAuth = true;
            } else {
                isAuth = false;
                LOG.error("TaskName: " + getTaskName() + ", Login failed. Reason: " + okErrorPacket.getMessage());
            }

            return isAuth;
        } catch (Exception e) {
            LOG.error("TaskName: " + getTaskName() + ", Login failed. Reason: " + e.getMessage());

            return false;
        }
    }

    private boolean queryBinlogFormat() throws IOException {
        try {
            QueryExecutor executor = new QueryExecutor(is, os);
            String cmd = "show global variables like 'binlog_format'";
            ResultSet rs = executor.query(cmd, getContext());
            List columnValues = rs.getFiledValues();
            boolean isQuery = true;
            if (columnValues == null || columnValues.size() != 2 || columnValues.get(1) == null) {
                LOG.error("TaskName: " + getTaskName()
                        + ", QueryConfig failed Reason:unexcepted binlog format query result.");
                isQuery = false;
            }
            BinlogFormat binlogFormat = BinlogFormat.valuesOf(columnValues.get(1));
            String eventName = String.format("slave(%s) -- db(%s:%d)", getTaskName(), currentSrcDbEntity.getHost(), currentSrcDbEntity.getPort());
            if (binlogFormat == null || !binlogFormat.isRow()) {
                isQuery = false;
                LOG.error("TaskName: " + getTaskName() + ", Unexcepted binlog format: " + binlogFormat.value);
            }

            Cat.logEvent("Slave.dbBinlogFormat", eventName, isQuery ? Message.SUCCESS : "1", "");
            if (isQuery) {
                LOG.info("TaskName: " + getTaskName() + ", Query config binlogformat is legal.");
            }
            return isQuery;
        } catch (Exception e) {
            LOG.error("TaskName: " + getTaskName() + ", QueryConfig failed Reason: " + e.getMessage());
            return false;
        }
    }

    private boolean queryBinlogImage() throws IOException {
        try {
            QueryExecutor executor = new QueryExecutor(is, os);
            String cmd = "show variables like 'binlog_row_image'";
            ResultSet rs = executor.query(cmd, getContext());
            List columnValues = rs.getFiledValues();
            boolean isQuery = true;
            if (columnValues == null || columnValues.size() == 0) {// 5.1
                isQuery = true;
            } else if (columnValues != null && columnValues.size() == 2 && columnValues.get(1) != null) {// 5.6
                BinlogRowImage binlogRowImage = BinlogRowImage.valuesOf(columnValues.get(1));
                isQuery = true;
                if (binlogRowImage == null || !binlogRowImage.isFull()) {
                    isQuery = false;
                    LOG.error("TaskName: " + getTaskName() + ", Unexcepted binlog row image: " + binlogRowImage.value);
                }
            } else {
                LOG.error("TaskName: " + getTaskName()
                        + ", QueryConfig failed Reason:unexcepted binlog row image query result.");
                isQuery = false;
            }
            String eventName = String.format("slave(%s) -- db(%s:%d)", getTaskName(), currentSrcDbEntity.getHost(), currentSrcDbEntity.getPort());
            Cat.logEvent("Slave.dbBinlogRowImage", eventName, isQuery ? Message.SUCCESS : "1", "");
            if (isQuery) {
                LOG.info("TaskName: " + getTaskName() + ", Query config binlog row image is legal.");
            }
            return isQuery;
        } catch (Exception e) {
            LOG.error("TaskName: " + getTaskName() + ", QueryConfig failed Reason: " + e.getMessage());
            return false;
        }
    }

• initConnect方法依次执行auth、queryBinlogFormat、queryBinlogImage方法；auth方法进行账号密码校验；queryBinlogFormat主要执行show global variables like 'binlog_format'命令；queryBinlogImage主要执行show variables like 'binlog_row_image'

initBinlogPosition

    protected void initBinlogPosition(BinlogInfo binlogInfo) throws IOException {
        if (binlogInfo == null) {
            List binaryLogs = getBinaryLogs();
            BinlogInfo begin = beginTime == null ? binaryLogs.get(binaryLogs.size() - 1) : binaryLogs.get(0);
            binlogInfo = new BinlogInfo(currentSrcDbEntity.getServerId(), begin.getBinlogFile(), 4l, 0, begin.getTimestamp());
        }

        getContext().setDBServerId(currentSrcDbEntity.getServerId());
        getContext().setBinlogFileName(binlogInfo.getBinlogFile());
        getContext().setBinlogStartPos(binlogInfo.getBinlogPosition());
        setBinlogInfo(binlogInfo);

        SystemStatusManager.addServer(getTaskName(), currentSrcDbEntity.getHost(), currentSrcDbEntity.getPort(), tableSet);
        SystemStatusManager.updateServerBinlog(getTaskName(), binlogInfo);
    }

• initBinlogPosition主要是将binlogInfo信息设置到PumaContext中

dumpBinlog

    private boolean dumpBinlog() {
        try {
            ComBinlogDumpPacket dumpBinlogPacket = (ComBinlogDumpPacket) PacketFactory.createCommandPacket(
                    PacketType.COM_BINLOG_DUMP_PACKET, getContext());
            dumpBinlogPacket.setBinlogFileName(getContext().getBinlogFileName());
            dumpBinlogPacket.setBinlogFlag(0);
            dumpBinlogPacket.setBinlogPosition(getContext().getBinlogStartPos());
            dumpBinlogPacket.setServerId(getServerId());
            dumpBinlogPacket.buildPacket(getContext());

            dumpBinlogPacket.write(os, getContext());

            OKErrorPacket dumpCommandResultPacket = (OKErrorPacket) PacketFactory.parsePacket(is,
                    PacketType.OKERROR_PACKET, getContext());

            if (dumpCommandResultPacket.isOk()) {
                LOG.info("TaskName: " + getTaskName() + ", Dump binlog command success.");

                return true;
            } else {
                LOG.error("TaskName: " + getTaskName() + ", Dump binlog failed. Reason: "
                        + dumpCommandResultPacket.getMessage());

                return false;
            }
        } catch (Exception e) {
            LOG.error("TaskName: " + getTaskName() + " Dump binlog failed. Reason: " + e.getMessage());

            return false;
        }

    }

• dumpBinlog方法主要是发送COM_BINLOG_DUMP_PACKET

processBinlog

    private void processBinlog() throws IOException {
        while (!isStop()) {
            BinlogPacket binlogPacket = (BinlogPacket) PacketFactory.parsePacket(is, PacketType.BINLOG_PACKET,
                    getContext());

            if (!binlogPacket.isOk()) {
                LOG.error("TaskName: " + getTaskName() + ", Binlog packet response error.");
                throw new IOException("TaskName: " + getTaskName() + ", Binlog packet response error.");
            } else {
                processBinlogPacket(binlogPacket);
            }
        }
    }

    protected void processBinlogPacket(BinlogPacket binlogPacket) throws IOException {
        BinlogEvent binlogEvent = parser.parse(binlogPacket.getBinlogBuf(), getContext());

        if (merging) {
            if (binlogEvent.getHeader().getTimestamp() >= runUntilTimestamp) {
                stop();
            }
        }

        SystemStatusManager.incServerParsedCounter(getTaskName());

        if (binlogEvent.getHeader().getEventType() == BinlogConstants.INTVAR_EVENT
                || binlogEvent.getHeader().getEventType() == BinlogConstants.RAND_EVENT
                || binlogEvent.getHeader().getEventType() == BinlogConstants.USER_VAR_EVENT) {
            LOG.error("TaskName: " + getTaskName() + ", Binlog_format is MIXED or STATEMENT ,System is not support.");
            String eventName = String.format("slave(%s) -- db(%s:%d)", getTaskName(), currentSrcDbEntity.getHost(), currentSrcDbEntity.getPort());
            Cat.logEvent("Slave.dbBinlogFormat", eventName, "1", "");
            Cat.logError("Puma.server.mixedorstatement.format", new IllegalArgumentException("TaskName: "
                    + getTaskName() + ", Binlog_format is MIXED or STATEMENT ,System is not support."));
            stopTask();
        }

        if (binlogEvent.getHeader().getEventType() != BinlogConstants.FORMAT_DESCRIPTION_EVENT) {
            getContext().setNextBinlogPos(binlogEvent.getHeader().getNextPosition());
        }

        if (binlogEvent.getHeader().getEventType() == BinlogConstants.ROTATE_EVENT) {
            processRotateEvent(binlogEvent);
        } else {
            processDataEvent(binlogEvent);
        }
    }

    protected void processRotateEvent(BinlogEvent binlogEvent) {
        RotateEvent rotateEvent = (RotateEvent) binlogEvent;
        getContext().setBinlogFileName(rotateEvent.getNextBinlogFileName());
        getContext().setBinlogStartPos(rotateEvent.getFirstEventPosition());
    }

    protected void processDataEvent(BinlogEvent binlogEvent) {
        DataHandlerResult dataHandlerResult = null;
        // 一直处理一个binlogEvent的多行，处理完每行马上分发，以防止一个binlogEvent包含太多ChangedEvent而耗费太多内存
        int eventIndex = 0;
        do {
            dataHandlerResult = dataHandler.process(binlogEvent, getContext());
            if (dataHandlerResult != null && !dataHandlerResult.isEmpty()) {
                ChangedEvent changedEvent = dataHandlerResult.getData();

                changedEvent.getBinlogInfo().setEventIndex(eventIndex++);

                updateOpsCounter(changedEvent);

                dispatch(changedEvent);
            }
        } while (dataHandlerResult != null && !dataHandlerResult.isFinished());

        if (binlogEvent.getHeader().getEventType() != BinlogConstants.FORMAT_DESCRIPTION_EVENT) {
            getContext().setBinlogStartPos(binlogEvent.getHeader().getNextPosition());
            setBinlogInfo(new BinlogInfo(getBinlogInfo().getServerId(), getBinlogInfo().getBinlogFile(), binlogEvent
                    .getHeader().getNextPosition(), 0, 0));
        }

        BinlogInfo binlogInfo = new BinlogInfo(getContext().getDBServerId(), getContext()
                .getBinlogFileName(), binlogEvent.getHeader().getNextPosition(), 0, binlogEvent.getHeader().getTimestamp());
        SystemStatusManager.updateServerBinlog(getTaskName(), binlogInfo);

        if (binlogEvent.getHeader().getNextPosition() != 0
                && StringUtils.isNotBlank(getContext().getBinlogFileName())
                && dataHandlerResult != null
                && !dataHandlerResult.isEmpty()
                && (dataHandlerResult.getData() instanceof DdlEvent || (dataHandlerResult.getData() instanceof RowChangedEvent && ((RowChangedEvent) dataHandlerResult
                .getData()).isTransactionCommit()))) {


            instanceStorageManager.setBinlogInfo(getTaskName(), binlogInfo);
        }
    }

－ processBinlog方法循环接收binlogPacket，然后执行processBinlogPacket；该方法通过parser.parse获取binlogEvent，对于FORMAT_DESCRIPTION_EVENT，则更新binlogEvent.getHeader().getNextPosition()到context中；对于ROTATE_EVENT则执行processRotateEvent，否则执行processDataEvent；processRotateEvent主要是更新binlogFileName及binlogStartPos；processDataEvent则主要是通过dataHandler.process(binlogEvent, getContext())处理，然后执行dispatch(changedEvent)

closeTransport

puma/puma/src/main/java/com/dianping/puma/taskexecutor/DefaultTaskExecutor.java

    private void closeTransport() {
        // Close in.
        try {
            if (this.is != null) {
                this.is.close();
            }
        } catch (IOException ioEx) {
            LOG.warn("Server " + this.getTaskName() + ", Failed to close the input stream.");
        } finally {
            this.is = null;
        }

        // Close os.
        try {
            if (this.os != null) {
                this.os.close();
            }
        } catch (IOException ioEx) {
            LOG.warn("Server " + this.getTaskName() + ", Failed to close the output stream");
        } finally {
            this.os = null;
        }

        // Close socket.
        try {
            if (this.mysqlSocket != null) {
                this.mysqlSocket.close();
            }
        } catch (IOException ioEx) {
            LOG.warn("Server " + this.getTaskName() + ", Failed to close the socket", ioEx);
        } finally {
            this.mysqlSocket = null;
        }
    }

• closeTransport主要是关闭InputStream、OutputStream及mysqlSocket

小结

DefaultTaskExecutor继承了AbstractTaskExecutor，其doStart方法通过instanceStorageManager.getBinlogInfo获取binlogInfo，若为null且beginTime不为null则从getBinlogByTimestamp获取binlogInfo，之后执行updateTableMetaInfoFetcher、connect、initConnect、initBinlogPosition、dumpBinlog、processBinlog方法；其doStop方法主要执行closeTransport、SystemStatusManager.deleteServer(getTaskName())方法

doc

• DefaultTaskExecutor