flink watermark不触发window计算，装逼失败的经历

最新推荐文章于 2025-07-15 17:37:13 发布

原创

最新推荐文章于 2025-07-15 17:37:13 发布 · 1.6k 阅读

1 ·

CC 4.0 BY-SA版权

博客主要围绕Flink程序展开，提到运行时需设置并行度为1，先启动nc并发送数据再启动程序。还分析了window窗口的触发机制，如TumblingEventTimeWindows的分配及触发逻辑。最后找出程序出错原因是越界，导致水印时间异常，Flink忽略更新。

注意问题：
1、设置并行度为1
2、先启动nc，并发送数据，哪怕直发送一条数据（为什么？），然后再idea启动程序
提前准备点数据源：

01,1586489566000
01,1586489567000
01,1586489568000
01,1586489569000
01,1586489570000
01,1586489571000
01,1586489572000
01,1586489573000
01,1586489574000
01,1586489575000
01,1586489576000
01,1586489577000
01,1586489578000
01,1586489579000
01,1586489589000

代码：

import net.minidev.json.JSONUtil;
import org.apache.flink.api.common.eventtime.*;
import org.apache.flink.api.common.functions.AggregateFunction;
import org.apache.flink.api.common.functions.FoldFunction;
import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.configuration.ConfigConstants;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.streaming.api.TimeCharacteristic;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.datastream.KeyedStream;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.datastream.WindowedStream;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.functions.windowing.WindowFunction;
import org.apache.flink.streaming.api.windowing.assigners.TumblingEventTimeWindows;
import org.apache.flink.streaming.api.windowing.time.Time;
import org.apache.flink.streaming.api.windowing.windows.TimeWindow;
import org.apache.flink.util.Collector;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;

public class WatermarkDemo {
    public static void main(String[] args) throws Exception {
        Configuration config = new Configuration();
//

最低0.47元/天解锁文章