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From Burak Yavuz <brk...@gmail.com>
Subject Re: Reload some static data during struct streaming
Date Mon, 13 Nov 2017 21:49:56 GMT
I think if you don't cache the jdbc table, then it should auto-refresh.

On Mon, Nov 13, 2017 at 1:21 PM, spark receiver <spark.receiver@gmail.com>
wrote:

> Hi
>
> I’m using struct streaming(spark 2.2)  to receive Kafka msg ,it works
> great. The thing is I need to join the Kafka message with a relative static
> table stored in mysql database (let’s call it metadata here).
>
> So is it possible to reload the metadata table after some time
> interval(like daily ) without restart running struct streaming?
>
> Snippet code as following :
>
> // df_meta contains important information to join with the dataframe read from kafka
>
> val df_meta = spark.read.format("jdbc").option("url", mysql_url).option(
> "dbtable", "v_entity_ap_rel").load()
>
> df_meta.cache()
>
> val df = spark.readStream
>   .format("kafka")
>   .option("kafka.bootstrap.servers", *“*x.x.x.x:9092").option("fetch.message.max.bytes",
"50000000").option("kafka.max.partition.fetch.bytes", "50000000")
>   .option("subscribe", "rawdb.raw_data")
>   .option("failOnDataLoss", true)
>   .option("startingOffsets", "latest")
>   .load()
>   .select($"value".as[Array[Byte]])
>   .map(avroDeserialize(_))
>   .as[ApRawData].select("APMAC", "RSSI", "sourceMacAddress", "updatingTime")
>   .join(df_meta.as("b"), $"a.apmac" === $"b.apmac*”*)
>
>
> df.selectExpr("ENTITYID", "CLIENTMAC", "STIME", "case when a.rrssi>=b.rssi then '1'
when a.rrssi < b.nearbyrssi then '3' else '2' end FLAG", "substring(stime,1,13) STIME_HOUR")
>   .distinct().writeStream.format("parquet").partitionBy("STIME_HOUR")
>   .option("checkpointLocation", "/user/root/t_cf_table_chpt").trigger(ProcessingTime("5
minutes"))
>   .start("T_CF_TABLE")
>   .awaitTermination()
>
>
> Mason
>

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