I have ever tried to use readStream and writeStream, but it throw "Uri
without authority: hdfs:/data/_spark_metadata" exception, which is not seen
in normal read mode.
The parquet path I specified is hdfs:///data
Regard,
Junfeng Chen
On Thu, Mar 8, 2018 at 9:38 AM, naresh Goud <nareshgoud.du...@gmail.com>
wrote:
> change it to readStream instead of read as below
>
> val df = spark
> .readStream
> .format("kafka")
> .option("kafka.bootstrap.servers", "host1:port1,host2:port2")
> .option("subscribe", "topic1")
> .load()
>
>
> Check is this helpful
>
> https://github.com/ndulam/KafkaSparkStreams/blob/master/SampleStreamApp/src/main/scala/com/naresh/org/SensorDataSave.scala
>
>
>
>
>
>
>
>
> Thanks,
> Naresh
> www.linkedin.com/in/naresh-dulam
> http://hadoopandspark.blogspot.com/
>
>
>
> On Wed, Mar 7, 2018 at 7:33 PM Junfeng Chen <darou...@gmail.com> wrote:
>
>> I am struggling in trying to read data in kafka and save them to parquet
>> file on hdfs by using spark streaming according to this post
>> https://stackoverflow.com/questions/45827664/read-
>> from-kafka-and-write-to-hdfs-in-parquet
>>
>> My code is similar to following
>>
>> val df = spark
>> .read
>> .format("kafka")
>> .option("kafka.bootstrap.servers", "host1:port1,host2:port2")
>> .option("subscribe", "topic1")
>> .load()
>> df.selectExpr("CAST(key AS STRING)", "CAST(value AS STRING)")
>> .as[(String, String)]
>>
>> .write.parquet("hdfs://data.parquet")
>>
>>
>> What the difference is I am writing in Java language.
>>
>> But in practice, this code just run once and then exit gracefully.
>> Although it produces the parquet file successfully and no any exception is
>> threw out , it runs like a normal spark program rather than a spark
>> streaming program.
>>
>> What should I do if want to read kafka and save them to parquet in batch?
>>
>> Regard,
>> Junfeng Chen
>>
>
