聊聊chronos的addMessage

序

本文主要研究一下chronos的addMessage

addMessage

DDMQ/carrera-chronos/src/main/java/com/xiaojukeji/chronos/services/MqPullService.java

public class MqPullService implements Runnable {
    private static final Logger LOGGER = LoggerFactory.getLogger(MqPullService.class);

    private static final PullConfig PULL_CONFIG = ConfigManager.getConfig().getPullConfig();
    private static final Batcher BATCHER = Batcher.getInstance();
    private volatile boolean shouldStop = false;
    private CountDownLatch cdl;

    private final List<Long> succOffsets = new ArrayList<>();
    private final List<Long> failOffsets = new ArrayList<>();
    private SimpleCarreraConsumer carreraConsumer;
    private String mqPullServiceName;

    private final int INTERNAL_PAIR_COUNT = 5000;
    private final BlockingQueue<InternalPair> blockingQueue = new ArrayBlockingQueue<>(INTERNAL_PAIR_COUNT);

    //......

    private void addMessage(final InternalKey internalKey, final InternalValue internalValue, final int action) {
        if (internalKey.getType() == MsgTypes.DELAY.getValue()) {
            MetricService.incPullQps(internalValue.getTopic(), MetricMsgAction.ADD, MetricMsgType.DELAY);

            if (BATCHER.checkAndPutToDefaultCF(internalKey, internalValue.toJsonString(), internalValue.getTopic(), action)) {
                MetricService.incWriteQps(internalValue.getTopic(), MetricMsgAction.ADD, MetricMsgType.DELAY, MetricMsgToOrFrom.DB);

                return;
            }

            MetricService.putMsgSizePercent(internalValue.getTopic(), internalValue.toJsonString().getBytes(Charsets.UTF_8).length);
            MetricService.incWriteQps(internalValue.getTopic(), MetricMsgAction.ADD, MetricMsgType.DELAY, MetricMsgToOrFrom.SEND);

            putToBlockingQueue(internalKey, internalValue);
        } else if (internalKey.getType() == MsgTypes.LOOP_DELAY.getValue()
                || internalKey.getType() == MsgTypes.LOOP_EXPONENT_DELAY.getValue()) {

            MetricMsgType msgType = MetricMsgType.LOOP_DELAY;
            if (internalKey.getType() == MsgTypes.LOOP_EXPONENT_DELAY.getValue()) {
                msgType = MetricMsgType.LOOP_EXPONENT_DELAY;
            }

            MetricService.incPullQps(internalValue.getTopic(), MetricMsgAction.ADD, msgType);

            while (true) {
                if (KeyUtils.isInvalidMsg(internalKey)) {
                    return;
                }

                // 循环消息只写入rocksdb一次, seek到的时候再进行添加
                if (BATCHER.checkAndPutToDefaultCF(internalKey, internalValue.toJsonString(), internalValue.getTopic(), action)) {
                    MetricService.incWriteQps(internalValue.getTopic(), MetricMsgAction.ADD, msgType, MetricMsgToOrFrom.DB);
                    return;
                }

                MetricService.incWriteQps(internalValue.getTopic(), MetricMsgAction.ADD, msgType, MetricMsgToOrFrom.SEND);

                putToBlockingQueue(new InternalKey(internalKey), internalValue);
                internalKey.nextUniqDelayMsgId();
            }
        } else {
            MetricService.incPullQps(internalValue.getTopic(), MetricMsgAction.ADD, MetricMsgType.UNKNOWN);

            LOGGER.error("should not go here, invalid message type:{}, internalKey:{}", internalKey.getType(),
                    internalKey.genUniqDelayMsgId());
        }
    }

    private void putToBlockingQueue(InternalKey internalKey, InternalValue internalValue) {
        try {
            blockingQueue.put(new InternalPair(internalKey, internalValue));
        } catch (InterruptedException e) {
            LOGGER.error("error while put to blockingQueue, dMsgId:{}", internalKey.genUniqDelayMsgId());
        }
    }

    //......
}

• MqPullService实现了Runnable接口，其addMessage方法执行BATCHER.checkAndPutToDefaultCF(internalKey, internalValue.toJsonString(), internalValue.getTopic(), action)

InternalKey

DDMQ/carrera-common/src/main/java/com/xiaojukeji/carrera/chronos/model/InternalKey.java

public class InternalKey {
    private static final String SEPARATOR = "-";
    private static final int LEN_UUID = 36;
    private static final long ONE_DAY_SECONDS = 24 * 60 * 60;

    private long timestamp;
    private int type;
    private long expire;
    private long times;
    private long timed;
    private long interval;
    private int innerTopicSeq;
    private String uuid;
    private int segmentNum;
    private int segmentIndex;

    //......
}

• InternalKey定义了timestamp、times、interval等属性

InternalValue

DDMQ/carrera-chronos/src/main/java/com/xiaojukeji/chronos/model/InternalValue.java

public class InternalValue {
    @JSONField(name="a")
    private String topic;

    @JSONField(name="b")
    private String body;

    @JSONField(name="c")
    private long createTime;

    @JSONField(name="d")
    private String tags;

    @JSONField(name="e")
    private Map<String, String> properties;

    //......
}

• InternalValue定义了topic、body、createTime、tags、properties属性

checkAndPutToDefaultCF

DDMQ/carrera-chronos/src/main/java/com/xiaojukeji/chronos/autobatcher/Batcher.java

public class Batcher {
    private static final Logger LOGGER = LoggerFactory.getLogger(Batcher.class);

    private static final int PULL_BATCH_ITEM_NUM = ConfigManager.getConfig().getPullConfig().getPullBatchItemNum();
    private static final int MSG_BYTE_BASE_LEN = ConfigManager.getConfig().getPullConfig().getMsgByteBaseLen();

    private WriteBatch wb = new WriteBatch();
    private volatile int itemNum = 0;
    private static volatile Batcher instance = null;

    public static volatile ReentrantLock lock = new ReentrantLock();

    //......

    public boolean checkAndPutToDefaultCF(final InternalKey internalKey, final String strVal, final String topic, final int action) {
        lock.lock();
        try {
            if (KeyUtils.afterSeekTimestamp(internalKey.getTimestamp())) {
                byte[] bytes = strVal.getBytes(Charsets.UTF_8);
                MetricService.putMsgSizePercent(topic, bytes.length);
                if (bytes.length <= MSG_BYTE_BASE_LEN) {
                    putToDefaultCF(internalKey.genUniqDelayMsgId(), bytes, topic, internalKey, action);
                } else {
                    // 如果字节数据超过一定长度, 则进行字节数组切分, 以便降低io.util
                    List<byte[]> list = ByteUtils.divideArray(bytes, MSG_BYTE_BASE_LEN);
                    final int segmentNum = list.size();
                    for (int segmentIndex = 0; segmentIndex < segmentNum; segmentIndex++) {
                        internalKey.setSegmentNum(segmentNum);
                        internalKey.setSegmentIndex(Constants.SEGMENT_INDEX_BASE + segmentIndex);
                        putToDefaultCF(internalKey.genUniqDelayMsgIdWithSegmentInfoIfHas(), list.get(segmentIndex), topic, internalKey, action);
                        LOGGER.info("segment split, dMsgId:{}, len:{}, value.totalLen:{}", internalKey.genUniqDelayMsgIdWithSegmentInfoIfHas(), list.get(segmentIndex).length, bytes.length);
                    }
                }
                return true;
            }
            return false;
        } finally {
            lock.unlock();
        }
    }

    public void putToDefaultCF(final String key, final byte[] value, final String topic, final InternalKey internalKey, final int action) {
        put(CFManager.CFH_DEFAULT, key.getBytes(Charsets.UTF_8), value, topic, internalKey, action);
    }

    private void put(final ColumnFamilyHandle cfh, final byte[] key, final byte[] value, final String topic, final InternalKey internalKey, final int action) {
        lock.lock();
        try {
            int len = 0;
            if (value != null) {
                len = value.length;
            }
            wb.put(cfh, key, value);

            LOGGER.info("put to cf, dMsgId:{}, len:{}", new String(key), len);

            itemNum++;
            checkFrequency();

            if (action == Actions.ADD.getValue()) {
                if (internalKey.getType() == MsgTypes.DELAY.getValue()) {
                    MetricService.incWriteQpsAfterSplit(topic, MetricMsgAction.ADD, MetricMsgType.DELAY);
                } else if (internalKey.getType() == MsgTypes.LOOP_DELAY.getValue()) {
                    MetricService.incWriteQpsAfterSplit(topic, MetricMsgAction.ADD, MetricMsgType.LOOP_DELAY);
                } else if (internalKey.getType() == MsgTypes.LOOP_EXPONENT_DELAY.getValue()) {
                    MetricService.incWriteQpsAfterSplit(topic, MetricMsgAction.ADD, MetricMsgType.LOOP_EXPONENT_DELAY);
                }
            } else {
                if (internalKey.getType() == MsgTypes.DELAY.getValue()) {
                    MetricService.incWriteQps(topic, MetricMsgAction.CANCEL, MetricMsgType.DELAY, MetricMsgToOrFrom.DB);
                    MetricService.incWriteQpsAfterSplit(topic, MetricMsgAction.CANCEL, MetricMsgType.DELAY);
                } else if (internalKey.getType() == MsgTypes.LOOP_DELAY.getValue()) {
                    MetricService.incWriteQps(topic, MetricMsgAction.CANCEL, MetricMsgType.LOOP_DELAY, MetricMsgToOrFrom.DB);
                    MetricService.incWriteQpsAfterSplit(topic, MetricMsgAction.CANCEL, MetricMsgType.LOOP_DELAY);
                } else if (internalKey.getType() == MsgTypes.LOOP_EXPONENT_DELAY.getValue()) {
                    MetricService.incWriteQps(topic, MetricMsgAction.CANCEL, MetricMsgType.LOOP_EXPONENT_DELAY, MetricMsgToOrFrom.DB);
                    MetricService.incWriteQpsAfterSplit(topic, MetricMsgAction.CANCEL, MetricMsgType.LOOP_EXPONENT_DELAY);
                }
            }
        } finally {
            lock.unlock();
        }
    }

    private void checkFrequency() {
        if (itemNum >= PULL_BATCH_ITEM_NUM) {
            flush();
        }
    }

     public void flush() {
        lock.lock();
        try {
            if (itemNum > 0) {
                // make sure write succ
                while (!RDB.writeSync(wb)) {
                    LOGGER.error("error while flush to db!");
                    try {
                        TimeUnit.MILLISECONDS.sleep(200);
                    } catch (InterruptedException e) {
                    }
                }
                wb.clear();
                itemNum = 0;
            }
        } finally {
            lock.unlock();
        }
    }

    //......
}    

• Batcher的checkAndPutToDefaultCF主要是执行putToDefaultCF，而putToDefaultCF主要是执行put方法，该方法会执行wb.put(cfh, key, value)，将数据写入到rocksdb的WriteBatch；之后执行checkFrequency在必要的时候进行flush；flush方法主要是执行RDB.writeSync(wb)以及wb.clear()

writeSync

DDMQ/carrera-chronos/src/main/java/com/xiaojukeji/chronos/db/RDB.java

public class RDB {
    private static final org.slf4j.Logger LOGGER = LoggerFactory.getLogger(RDB.class);

    static RocksDB DB;

    public static void init(final String dbPath) {
        try {
            final long start = System.currentTimeMillis();
            boolean result = FileIOUtils.createOrExistsDir(new File(dbPath));
            assert(result != false);

            result = FileIOUtils.createOrExistsDir(new File(DB_PATH_BACKUP));
            assert(result != false);

            result = FileIOUtils.createOrExistsDir(new File(DB_PATH_RESTORE));
            assert(result != false);

            DB = RocksDB.open(OptionsConfig.DB_OPTIONS, dbPath, CF_DESCRIPTORS, CF_HANDLES);
            assert (DB != null);

            initCFManger(CF_HANDLES);

            final long cost = System.currentTimeMillis() - start;
            LOGGER.info("succ open rocksdb, path:{}, cost:{}ms", dbPath, cost);
        } catch (RocksDBException e) {
            LOGGER.error("error while open rocksdb, path:{}, err:{}", dbPath, e.getMessage(), e);
        }
    }

    //......

    public static boolean writeSync(final WriteBatch writeBatch) {
        return write(OptionsConfig.WRITE_OPTIONS_SYNC, writeBatch);
    }

    private static boolean write(final WriteOptions writeOptions, final WriteBatch writeBatch) {
        try {
            DB.write(writeOptions, writeBatch);
            LOGGER.debug("succ write writeBatch, size:{}", writeBatch.count());
        } catch (RocksDBException e) {
            // TODO: 2017/11/8 上报写入失败
            LOGGER.error("error while write batch, err:{}", e.getMessage(), e);
            return false;
        }
        return true;
    }

    //......
}

• writeSync方法主要是使用OptionsConfig.WRITE_OPTIONS_SYNC参数执行RocksDB.write方法

小结

MqPullService实现了Runnable接口，其addMessage方法执行BATCHER.checkAndPutToDefaultCF(internalKey, internalValue.toJsonString(), internalValue.getTopic(), action)；Batcher的checkAndPutToDefaultCF主要是执行putToDefaultCF，而putToDefaultCF主要是执行put方法，该方法会执行wb.put(cfh, key, value)，将数据写入到rocksdb的WriteBatch；之后执行checkFrequency在必要的时候进行flush；flush方法主要是执行RDB.writeSync(wb)以及wb.clear()

doc

• carrera-chronos