Hi Kwon,
Was trying out spark XML library . I keep on getting errors in inferring
schema. Looks like it cannot infer single line XML data.
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-------- Original message --------
From: Hyukjin Kwon <gurwls...@gmail.com>
Date:21/08/2016 15:40 (GMT+05:30)
To: Jörn Franke <jornfra...@gmail.com>
Cc: Diwakar Dhanuskodi <diwakar.dhanusk...@gmail.com>, Felix Cheung
<felixcheun...@hotmail.com>, user <user@spark.apache.org>
Subject: Re: Best way to read XML data from RDD
Hi Diwakar,
Spark XML library can take RDD as source.
```
val df = new XmlReader()
.withRowTag("book")
.xmlRdd(sqlContext, rdd)
```
If performance is critical, I would also recommend to take care of creation and
destruction of the parser.
If the parser is not serializble, then you can do the creation for each
partition within mapPartition just like
https://github.com/apache/spark/blob/ac84fb64dd85257da06f93a48fed9bb188140423/sql/core/src/main/scala/org/apache/spark/sql/DataFrameReader.scala#L322-L325
I hope this is helpful.
2016-08-20 15:10 GMT+09:00 Jörn Franke <jornfra...@gmail.com>:
I fear the issue is that this will create and destroy a XML parser object 2 mio
times, which is very inefficient - it does not really look like a parser
performance issue. Can't you do something about the format choice? Ask your
supplier to deliver another format (ideally avro or sth like this?)?
Otherwise you could just create one XML Parser object / node, but sharing this
among the parallel tasks on the same node is tricky.
The other possibility could be simply more hardware ...
On 20 Aug 2016, at 06:41, Diwakar Dhanuskodi <diwakar.dhanusk...@gmail.com>
wrote:
Yes . It accepts a xml file as source but not RDD. The XML data embedded
inside json is streamed from kafka cluster. So I could get it as RDD.
Right now I am using spark.xml XML.loadstring method inside RDD map
function but performance wise I am not happy as it takes 4 minutes to parse
XML from 2 million messages in a 3 nodes 100G 4 cpu each environment.
Sent from Samsung Mobile.
-------- Original message --------
From: Felix Cheung <felixcheun...@hotmail.com>
Date:20/08/2016 09:49 (GMT+05:30)
To: Diwakar Dhanuskodi <diwakar.dhanusk...@gmail.com>, user
<user@spark.apache.org>
Cc:
Subject: Re: Best way to read XML data from RDD
Have you tried
https://github.com/databricks/spark-xml
?
On Fri, Aug 19, 2016 at 1:07 PM -0700, "Diwakar Dhanuskodi"
<diwakar.dhanusk...@gmail.com> wrote:
Hi,
There is a RDD with json data. I could read json data using rdd.read.json . The
json data has XML data in couple of key-value paris.
Which is the best method to read and parse XML from rdd. Is there any specific
xml libraries for spark. Could anyone help on this.
Thanks.
