My question was how to do this in Hadoop? Could somebody point me to some
examples?
On Tue, Aug 18, 2015 at 10:43 PM, UMESH CHAUDHARY <umesh9...@gmail.com>
wrote:
> Of course, Java or Scala can do that:
> 1) Create a FileWriter with append or roll over option
> 2) For each RDD create a StringBuilder after applying your filters
> 3) Write this StringBuilder to File when you want to write (The duration
> can be defined as a condition)
>
> On Tue, Aug 18, 2015 at 11:05 PM, Mohit Anchlia <mohitanch...@gmail.com>
> wrote:
>
>> Is there a way to store all the results in one file and keep the file
>> roll over separate than the spark streaming batch interval?
>>
>> On Mon, Aug 17, 2015 at 2:39 AM, UMESH CHAUDHARY <umesh9...@gmail.com>
>> wrote:
>>
>>> In Spark Streaming you can simply check whether your RDD contains any
>>> records or not and if records are there you can save them using
>>> FIleOutputStream:
>>>
>>> DStream.foreachRDD(t=> { var count = t.count(); if (count>0){ // SAVE
>>> YOUR STUFF} };
>>>
>>> This will not create unnecessary files of 0 bytes.
>>>
>>> On Mon, Aug 17, 2015 at 2:51 PM, Akhil Das <ak...@sigmoidanalytics.com>
>>> wrote:
>>>
>>>> Currently, spark streaming would create a new directory for every batch
>>>> and store the data to it (whether it has anything or not). There is no
>>>> direct append call as of now, but you can achieve this either with
>>>> FileUtil.copyMerge
>>>> <http://apache-spark-user-list.1001560.n3.nabble.com/save-spark-streaming-output-to-single-file-on-hdfs-td21124.html#a21167>
>>>> or have a separate program which will do the clean up for you.
>>>>
>>>> Thanks
>>>> Best Regards
>>>>
>>>> On Sat, Aug 15, 2015 at 5:20 AM, Mohit Anchlia <mohitanch...@gmail.com>
>>>> wrote:
>>>>
>>>>> Spark stream seems to be creating 0 bytes files even when there is no
>>>>> data. Also, I have 2 concerns here:
>>>>>
>>>>> 1) Extra unnecessary files is being created from the output
>>>>> 2) Hadoop doesn't work really well with too many files and I see that
>>>>> it is creating a directory with a timestamp every 1 second. Is there a
>>>>> better way of writing a file, may be use some kind of append mechanism
>>>>> where one doesn't have to change the batch interval.
>>>>>
>>>>
>>>>
>>>
>>
>
