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From 张万新 <kevinzwx1...@gmail.com>
Subject Re: [SS]How to add a column with custom system time?
Date Wed, 13 Sep 2017 03:33:02 GMT
*Yes, my code is shown below*
/**
    * input
    */
  val logs = spark
    .readStream
    .format("kafka")
    .option("kafka.bootstrap.servers", BROKER_SERVER)
    .option("subscribe", TOPIC)
    .option("startingOffset", "latest")
    .load()

  /**
    * process
    */
  val logValues = logs.selectExpr("CAST(value AS STRING)").as[(String)]

  val events = logValues
    .map(parseFunction)
    .select(
      $"_1".alias("date").cast("timestamp"),
      $"_2".alias("uuid").cast("string")
    )

  val results = events
    .withWatermark("date", "1 day")
    .dropDuplicates("uuid", "date")
    .groupBy($"date")
    .count()
    .withColumn("window", window(current_timestamp(), "15 minutes"))

  /**
    * output
    */
  val query = results
    .writeStream
    .outputMode("update")
    .format("console")
    .option("truncate", "false")
    .trigger(Trigger.ProcessingTime("1 seconds"))
    .start()

  query.awaitTermination()

*and I use play json to parse input logs from kafka ,the parse function is
like*

  def parseFunction(str: String): (Long, String) = {
    val json = Json.parse(str)
    val timestamp = (json \ "time").get.toString().toLong
    val date = (timestamp / (60 * 60 * 24) * 24 -8) * 60 * 60
    val uuid = (json \ "uuid").get.toString()
    (date, uuid)
  }

Michael Armbrust <michael@databricks.com>于2017年9月13日周三 上午2:36写道:

> Can you show all the code?  This works for me.
>
> On Tue, Sep 12, 2017 at 12:05 AM, 张万新 <kevinzwx1992@gmail.com> wrote:
>
>> The spark version is 2.2.0
>>
>> Michael Armbrust <michael@databricks.com>于2017年9月12日周二 下午12:32写道:
>>
>>> Which version of spark?
>>>
>>> On Mon, Sep 11, 2017 at 8:27 PM, 张万新 <kevinzwx1992@gmail.com> wrote:
>>>
>>>> Thanks for reply, but using this method I got an exception:
>>>>
>>>> "Exception in thread "main"
>>>> org.apache.spark.sql.streaming.StreamingQueryException: nondeterministic
>>>> expressions are only allowed in
>>>>
>>>> Project, Filter, Aggregate or Window"
>>>>
>>>> Can you give more advice?
>>>>
>>>> Michael Armbrust <michael@databricks.com>于2017年9月12日周二
上午4:48写道:
>>>>
>>>>> import org.apache.spark.sql.functions._
>>>>>
>>>>> df.withColumn("window", window(current_timestamp(), "15 minutes"))
>>>>>
>>>>> On Mon, Sep 11, 2017 at 3:03 AM, 张万新 <kevinzwx1992@gmail.com>
wrote:
>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> In structured streaming how can I add a column to a dataset with
>>>>>> current system time aligned with 15 minutes?
>>>>>>
>>>>>> Thanks.
>>>>>>
>>>>>
>>>>>
>>>
>

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