代码如下:
package com.cuichunchi.watermark;
import org.apache.flink.api.common.eventtime.SerializableTimestampAssigner;
import org.apache.flink.api.common.eventtime.WatermarkStrategy;
import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.api.java.tuple.Tuple3;
import org.apache.flink.configuration.Configuration;
import org.apache.flink.configuration.RestOptions;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.functions.KeyedProcessFunction;
import org.apache.flink.streaming.api.functions.ProcessFunction;
import org.apache.flink.streaming.api.functions.windowing.ProcessWindowFunction;
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 org.apache.flink.util.OutputTag;
import java.text.SimpleDateFormat;
import java.time.Duration;
import java.util.Date;
import java.util.Iterator;
public class TestWaterMark {
public static void main(String[] args) throws Exception {
Configuration conf = new Configuration();
conf.setString(RestOptions.BIND_PORT,"19082");
StreamExecutionEnvironment env = StreamExecutionEnvironment
.createLocalEnvironmentWithWebUI(conf);
// .getExecutionEnvironment();
env.setParallelism(2);
env.disableOperatorChaining();
DataStreamSource socketTextStream = env.socketTextStream("s201", 9099);
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
SingleOutputStreamOperator> tuple2Map = socketTextStream.map(new MapFunction>() {
@Override
public Tuple3 map(String value) throws Exception {
return new Tuple3<>(value.split(",")[0],1, Long.parseLong(value.split(",")[1]));
}
});
//提取时间戳
SingleOutputStreamOperator> tuple2WMDS = tuple2Map.assignTimestampsAndWatermarks(
//设置几秒watermark
WatermarkStrategy.>forBoundedOutOfOrderness(Duration.ofSeconds(2))
.withTimestampAssigner(new SerializableTimestampAssigner>() {
@Override
public long extractTimestamp(Tuple3 element, long recordTimestamp) {
System.out.println("-----key:"+element.f0+"-----提取时间戳:" + dateFormat.format( element.f2 )+ "," +
"默认处理时间戳:" + recordTimestamp);
return element.f2;
}
})
//如果窗口一直没有数据,导致watermark不会向前推进,那么就一直不会触发窗口计算,该参数就是解决窗口不会被触发的问题
//后面有时间再测试这个,需要多个分区测试
// .withIdleness(Duration.ofSeconds(10))
);
//TODO 说明:
//简单实时聚合
//TODO 通过源码 TimeWindow#getWindowStartWithOffset()来生成得watermark
//TODO org.apache.flink.streaming.api.windowing.assigners.TumblingEventTimeWindows.assignWindows()
//TODO org.apache.flink.streaming.api.windowing.windows.TimeWindow.getWindowStartWithOffset()
//开窗聚合
OutputTag> diltyData = new OutputTag>("data"){};
SingleOutputStreamOperator> processDS =
tuple2WMDS
.keyBy(value -> value.f0)
.window(TumblingEventTimeWindows.of(Time.seconds(5)))
// 容忍延迟 几秒的数据
.allowedLateness(Time.seconds(5))
//将延迟到的数据写入到侧输出流
.sideOutputLateData(diltyData)
.process(new ProcessWindowFunction, Tuple2, String,
TimeWindow>() {
@Override
public void process(String s, Context context, Iterable> elements,
Collector> out) throws Exception {
long start = context.window().getStart();
long end = context.window().getEnd();
long currentWatermark = context.currentWatermark();
int numberOfParallelSubtasks = getRuntimeContext().getNumberOfParallelSubtasks();
System.out.println("======参数打印:当前subtasks:"+numberOfParallelSubtasks+",key:"+s+ ",elements:"+elements.toString()
+",当前开始window:["+dateFormat.format(start)+"],当前结束window:["+dateFormat.format(end)+
"],当前watermark:"+dateFormat.format(currentWatermark));
Iterator> it = elements.iterator();
int sum = 0;
while (it.hasNext()){
Tuple3 next = it.next();
sum += next.f1;
}
out.collect(new Tuple2<>(s,sum));
}
}).setParallelism(2);
processDS.print("结果输出====》");
processDS.getSideOutput(diltyData).print("迟到数据测输出流====》");
env.execute();
}
}
单分区测试结果:
没有设置watermark
-------提取时间戳:2020-04-10 11:32:46,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:47,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:48,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:49,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:50,默认处理时间戳:-9223372036854775808
======参数打印:01,elements:[(01,1,1586489566000), (01,1,1586489567000), (01,1,1586489568000), (01,1,1586489569000)],当前开始window:[2020-04-10 11:32:45],当前结束window:[2020-04-10 11:32:50],当前watermark:2020-04-10 11:32:49 (到50触发这个窗口计算)
(01,4)
-------提取时间戳:2020-04-10 11:32:51,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:52,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:53,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:54,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:55,默认处理时间戳:-9223372036854775808
======参数打印:01,elements:[(01,1,1586489570000), (01,1,1586489571000), (01,1,1586489572000), (01,1,1586489573000), (01,1,1586489574000)],当前开始window:[2020-04-10 11:32:50],当前结束window:[2020-04-10 11:32:55],当前watermark:2020-04-10 11:32:54
(01,5)
设置2秒watermark
-------提取时间戳:2020-04-10 11:32:46,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:47,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:48,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:50,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:51,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:52,默认处理时间戳:-9223372036854775808
======参数打印:01,elements:[(01,1,1586489566000), (01,1,1586489567000), (01,1,1586489568000)],当前开始window:[2020-04-10 11:32:45],当前结束window:[2020-04-10 11:32:50],当前watermark:2020-04-10 11:32:49 (到52秒触发这个窗口计算,多等待了2秒)
结果输出====》> (01,3)
-------提取时间戳:2020-04-10 11:32:49,默认处理时间戳:-9223372036854775808 ------ 丢数据了,因为上一个窗口已经计算过了,被销毁了
-------提取时间戳:2020-04-10 11:32:54,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:55,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:56,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:57,默认处理时间戳:-9223372036854775808
======参数打印:01,elements:[(01,1,1586489570000), (01,1,1586489571000), (01,1,1586489572000), (01,1,1586489574000)],当前开始window:[2020-04-10 11:32:50],当前结束window:[2020-04-10 11:32:55],当前watermark:2020-04-10 11:32:54 (到57秒才开始这个窗口的计算)
结果输出====》> (01,4)
设置5秒的watermark
-------提取时间戳:2020-04-10 11:32:46,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:47,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:50,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:53,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:54,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:32:55,默认处理时间戳:-9223372036854775808
======参数打印:01,elements:[(01,1,1586489566000), (01,1,1586489567000)],当前开始window:[2020-04-10 11:32:45],当前结束window:[2020-04-10 11:32:50],当前watermark:2020-04-10 11:32:49 (到55秒触发这个窗口的计算,延迟了5秒)
结果输出====》> (01,2)
-------提取时间戳:2020-04-10 11:32:57,默认处理时间戳:-9223372036854775808
-------提取时间戳:2020-04-10 11:33:00,默认处理时间戳:-9223372036854775808
======参数打印:01,elements:[(01,1,1586489570000), (01,1,1586489573000), (01,1,1586489574000)],当前开始window:[2020-04-10 11:32:50],当前结束window:[2020-04-10 11:32:55],当前watermark:2020-04-10 11:32:54 (到60的适合触发窗口计算,延迟5秒)
结果输出====》> (01,3)
设置两个分区:
14:56:57.779 [flink-akka.actor.default-dispatcher-36] ERROR org.apache.flink.runtime.rest.handler.job.JobDetailsHandler - Exception occurred in REST handler: Job aa25794d54a90d9f39bc3367c8661a09 not found
14:56:57.835 [flink-akka.actor.default-dispatcher-32] ERROR org.apache.flink.runtime.rest.handler.job.JobExceptionsHandler - Exception occurred in REST handler: Job aa25794d54a90d9f39bc3367c8661a09 not found
-----key:01-----提取时间戳:2020-04-10 11:32:46,默认处理时间戳:-9223372036854775808
-----key:02-----提取时间戳:2020-04-10 11:32:46,默认处理时间戳:-9223372036854775808
-----key:01-----提取时间戳:2020-04-10 11:32:48,默认处理时间戳:-9223372036854775808
-----key:02-----提取时间戳:2020-04-10 11:32:53,默认处理时间戳:-9223372036854775808
-----key:01-----提取时间戳:2020-04-10 11:32:52,默认处理时间戳:-9223372036854775808
======参数打印:当前subtasks:2,key:01,elements:[(01,1,1586489566000), (01,1,1586489568000)],当前开始window:[2020-04-10 11:32:45],当前结束window:[2020-04-10 11:32:50],当前watermark:2020-04-10 11:32:49
======参数打印:当前subtasks:2,key:02,elements:[(02,1,1586489566000)],当前开始window:[2020-04-10 11:32:45],当前结束window:[2020-04-10 11:32:50],当前watermark:2020-04-10 11:32:49
结果输出====》:1> (01,2)
结果输出====》:1> (02,1)
说明:提取并生成watermark是在map阶段开始的,从socket获取数据后轮询的发送到maptask,然后生成的watermark广播到下游,在下游task中,接受到的watermark会按照木板效应取最小的时间戳来进行窗口统计,所以第一次发送46秒的数据,生成44秒的watermark并发往分区0号中,第二次发送46的数据,生成44秒的watermark并发往分区1号中,第三次发送48秒的数据并生成46秒的watermark并发往分区0号,第四次发送53秒的数据并生成51秒的watermark并发往分区1号,此时的分区watermark为(48,51)并没有触发窗口计算,因为取48秒的这个最小值,还未到触发窗口计算的时机,继续第五次发送52秒的数据并生成50秒的watermark并发往0号分区,此时分区watermark(50,51),那么取最小的50,则触发了窗口的计算。



