Question

我想使用Flink CEP实现事件警报。

我的用例：我想将时间窗口应用一小时，如果设备使用率大于某个阈值（100），那么我想提醒最终用户并在特定时间窗口中仅触发一次该警报。

问题：

按时间窗口，Pattern流在时间窗口完成后获取元素。所以它在实时场景中不起作用。有没有解决方案？
我可以在时间窗前获取Pattern流中的元素吗？
如果为最终用户找到匹配的模式，我该如何仅提醒一次？

的SourceStream：

KeyedStream<UsageStatistics, Tuple> keyedStreamByMac = kafkaSourceStream.keyBy(UsageStatisticsKey.clusterId.name(), UsageStatisticsKey.deviceMac.name());

SingleOutputStreamOperator<MacTotalUsage> macStream = keyedStreamByMac.timeWindow(Time.hours(1)).reduce(new ReduceFunction<UsageStatistics>() {
            @Override
            public UsageStatistics reduce(UsageStatistics value1, UsageStatistics value2) throws Exception {
                UsageStatistics statistics = new UsageStatistics();
                statistics.setDeviceMac(value1.getDeviceMac());
                statistics.setDownloadBytes(value1.getDownloadBytes() + value2.getDownloadBytes());
                statistics.setUploadBytes(value1.getUploadBytes() + value2.getUploadBytes());
                statistics.setClusterId(value1.getClusterId());
                return statistics;
            }
        }).map(new MapFunction<UsageStatistics, MacTotalUsage>() {

            @Override
            public MacTotalUsage map(UsageStatistics value) {
                MacTotalUsage macTotalUsage = new MacTotalUsage();
                macTotalUsage.setClusterId(value.getClusterId());
                macTotalUsage.setDeviceMac(value.getDeviceMac());
                macTotalUsage.setTotalDownloadBytes(value.getDownloadBytes());
                macTotalUsage.setTotalUploadBytes(value.getUploadBytes());
                return macTotalUsage;
            }
        });

模式：

Pattern<MacTotalUsage, MacTotalUsage> maxUsagePattern = Pattern.<MacTotalUsage>begin("first").where(new SimpleCondition<MacTotalUsage>() {
            @Override
            public boolean filter(MacTotalUsage event) throws Exception {
                return (event.getTotalDownloadBytes() >= 100);
            }
        });

PatternStream：

DataStreamOperator<MaxUsageAlert> maxUsageAlert = CEP.pattern(macStream, maxUsagePattern).select(new PatternSelectFunction<MacTotalUsage, MaxUsageAlert>() {
    @Override
    public MaxUsageAlert select(Map<String, List<MacTotalUsage>> pattern) throws Exception {
        MacTotalUsage event = pattern.get("first").get(0);
        return new MaxUsageAlert(event);
    }
});

如果有人提供解决方案，那将非常有用。

如何使用时间窗口实现Flink CEP？

0 个答案: