1、概述
在生产场景值，经常需要和上游、下游对数，离线场景可以直接 group by 再 count ，但是实时场景中，如果使用 kafka 作为中间件，中间经过几个 job 的过滤转化后，再对照像 Doris 或 Clickhouse 中最终层的数据，如果出现缺失，很难判断是哪一层缺失的。
2、使用 侧流输出+处理时间的滚动窗口+状态进行数据量级统计
package com.flink.feature.windowcount;import org.apache.flink.api.common.state.MapState;
import org.apache.flink.api.common.state.MapStateDescriptor;
import org.apache.flink.api.java.functions.KeySelector;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.api.java.tuple.Tuple4;
import org.apache.flink.configuration.Configuration;
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.ProcessFunction;
import org.apache.flink.streaming.api.functions.windowing.ProcessWindowFunction;
import org.apache.flink.streaming.api.windowing.assigners.TumblingProcessingTimeWindows;
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;/*** 1、先输入数据* 1* 1* 1* 1* 输出结果* main=>:8> 业务处理=>1* main=>:1> 业务处理=>1* main=>:2> 业务处理=>1* main=>:3> 业务处理=>1* 每10秒每个key接受到的数据量=>:2> (1698913020000,1698913030000,窗口统计=>1,4)** 2、再输入数据* 1* 2* 2* 3* 3* 4* 4* 输出结果* main=>:4> 业务处理=>1* main=>:5> 业务处理=>2* main=>:6> 业务处理=>2* main=>:7> 业务处理=>3* main=>:8> 业务处理=>3* main=>:1> 业务处理=>4* main=>:2> 业务处理=>4* 每10秒每个key接受到的数据量=>:2> (1698913030000,1698913040000,窗口统计=>1,1)* 每10秒每个key接受到的数据量=>:7> (1698913030000,1698913040000,窗口统计=>4,2)* 每10秒每个key接受到的数据量=>:6> (1698913030000,1698913040000,窗口统计=>2,2)* 每10秒每个key接受到的数据量=>:6> (1698913030000,1698913040000,窗口统计=>3,2)*/public class UseWindowValidateData {public static void main(String[] args) throws Exception {StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();OutputTag<Tuple2<String,Integer>> windowCountTag = new OutputTag<Tuple2<String,Integer>>("window_count"){};DataStreamSource<String> source = env.socketTextStream("localhost", 8888);SingleOutputStreamOperator<String> process = source.process(new ProcessFunction<String, String>() {@Overridepublic void processElement(String input, ProcessFunction<String, String>.Context ctx, Collector<String> collector) throws Exception {ctx.output(windowCountTag,new Tuple2<>("窗口统计=>"+input,1));collector.collect("业务处理=>" + input);}});process.getSideOutput(windowCountTag).keyBy(new KeySelector<Tuple2<String,Integer>, String>() {@Overridepublic String getKey(Tuple2<String,Integer> tp) throws Exception {return tp.f0;}}).window(TumblingProcessingTimeWindows.of(Time.seconds(10))).process(new ProcessWindowFunction<Tuple2<String, Integer>, Tuple4<String,String,String,Integer>, String, TimeWindow>() {private MapState<String, Integer> mapState;@Overridepublic void open(Configuration parameters) throws Exception {MapStateDescriptor<String, Integer> stateDescriptor = new MapStateDescriptor<>("map-state", String.class, Integer.class);mapState = getRuntimeContext().getMapState(stateDescriptor);}@Overridepublic void process(String key, ProcessWindowFunction<Tuple2<String, Integer>, Tuple4<String, String, String, Integer>, String, TimeWindow>.Context ctx, Iterable<Tuple2<String, Integer>> elements, Collector<Tuple4<String, String, String, Integer>> out) throws Exception {for (Tuple2<String, Integer> tp : elements) {Integer res = mapState.get(tp.f0);if (res == null) {res = 0;}res += 1;mapState.put(tp.f0, res);}out.collect(new Tuple4<>(String.valueOf(ctx.window().getStart()),String.valueOf(ctx.window().getEnd()),key,mapState.get(key)));// 每个窗口计算后清空状态mapState.clear();}}).print("每10秒每个key接受到的数据量=>");process.print("main=>");env.execute();}
}3、测试结果
1）先输入数据
1
1
1
1
输出结果
main=>:8> 业务处理=>1
main=>:1> 业务处理=>1
main=>:2> 业务处理=>1
main=>:3> 业务处理=>1
每10秒每个key接受到的数据量=>:2> (1698913020000,1698913030000,窗口统计=>1,4)
2）再输入数据
1
2
2
3
3
4
4
输出结果
main=>:4> 业务处理=>1
main=>:5> 业务处理=>2
main=>:6> 业务处理=>2
main=>:7> 业务处理=>3
main=>:8> 业务处理=>3
main=>:1> 业务处理=>4
main=>:2> 业务处理=>4
每10秒每个key接受到的数据量=>:2> (1698913030000,1698913040000,窗口统计=>1,1)
每10秒每个key接受到的数据量=>:7> (1698913030000,1698913040000,窗口统计=>4,2)
每10秒每个key接受到的数据量=>:6> (1698913030000,1698913040000,窗口统计=>2,2)
每10秒每个key接受到的数据量=>:6> (1698913030000,1698913040000,窗口统计=>3,2)
)
