窗口开始时间反映在ROWTIME
KSQL 消息和 Kafka 消息的时间戳中。您可以使用标准 API 访问此时间戳以处理 Kafka 消息。
AFAIKkafka-console-consumer
不支持显示时间戳。然而,类似的事情kafkacat
。
这是 KSQL 中的一些聚合数据,ROWTIME
显示了窗口的开头(并TIMESTAMPTOSTRING
用于漂亮地打印它):
ksql> SELECT TIMESTAMPTOSTRING(ROWTIME, 'yyyy-MM-dd HH:mm:ss'), ROWTIME, STARS, STAR_COUNT FROM RATINGS_AGG2;
2018-06-27 09:30:00 | 1530091800000 | 1 | 2
2018-06-27 09:30:00 | 1530091800000 | 4 | 6
2018-06-27 09:30:00 | 1530091800000 | 2 | 2
2018-06-27 09:30:00 | 1530091800000 | 3 | 3
现在相同的主题kafkacat
:
$ kafkacat -b localhost:9092 -C -K: \
-f '\nTimestamp: %T\t\tValue (%S bytes): %s' \
-t RATINGS_AGG2
Timestamp: 1530091800000 Value (26 bytes): {"STAR_COUNT":1,"STARS":1}
Timestamp: 1530091800000 Value (26 bytes): {"STAR_COUNT":2,"STARS":1}
Timestamp: 1530091800000 Value (26 bytes): {"STAR_COUNT":3,"STARS":3}
Timestamp: 1530091800000 Value (26 bytes): {"STAR_COUNT":5,"STARS":1}
Timestamp: 1530091800000 Value (26 bytes): {"STAR_COUNT":6,"STARS":3}
Timestamp: 1530091800000 Value (26 bytes): {"STAR_COUNT":7,"STARS":1}
Timestamp: 1530091800000 Value (26 bytes): {"STAR_COUNT":7,"STARS":3}
Timestamp: 1530091800000 Value (26 bytes): {"STAR_COUNT":9,"STARS":1}
Timestamp: 1530091800000 Value (26 bytes): {"STAR_COUNT":9,"STARS":3}