flink-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Tzu-Li (Gordon) Tai" <tzuli...@gmail.com>
Subject Re: Default timestamps for Event Time when no Watermark Assigner used?
Date Tue, 23 Aug 2016 11:29:12 GMT
Hi,

For the Kinesis consumer, when you use Event Time but do not explicitly
assign timestamps, the Kinesis server-side timestamp (the time which
Kinesis received the record) is attached to the record as default, not
Flinkā€™s ingestion time.

Does this answer your question?

Regards,
Gordon


On August 23, 2016 at 6:42:26 PM, Sameer W (sameer@axiomine.com) wrote:

Hi,

If you do not explicitly assign timestamps and watermarks when using Event
Time, does it automatically default to using Ingestion Time?

I was reading the Kinesis integration section and came across the note
below and which raised the above question. I saw another place where you
explicitly use Event Time with ingestion time with the following
- .assignTimestampsAndWatermarks(new IngestionTimeExtractor<>());.

Does that line have to called explicitly or is it the default?


"If streaming topologies choose to use the event time notion
<https://ci.apache.org/projects/flink/flink-docs-master/apis/streaming/event_time.html>
for
record timestamps, an *approximate arrival timestamp* will be used by
default. This timestamp is attached to records by Kinesis once they were
successfully received and stored by streams. Note that this timestamp is
typically referred to as a Kinesis server-side timestamp, and there are no
guarantees about the accuracy or order correctness (i.e., the timestamps
may not always be ascending)."

Thanks,
Sameer

Mime
View raw message