Re: Do transformation functions on RDD invoke a Job [sc.runJob]?

[Praveen Devarao]

Cool!! Thanks for the clarification Mike.

Thanking You
-
Praveen Devarao
Spark Technology Centre
IBM India Software Labs
-
"Courage doesn't always roar. Sometimes courage is the quiet voice at the 
end of the day saying I will try again"



From:   Michael Armbrust <mich...@databricks.com>
To: Praveen Devarao/India/IBM@IBMIN
Cc: Reynold Xin <r...@databricks.com>, "d...@spark.apache.org" 
<d...@spark.apache.org>, user <user@spark.apache.org>
Date:   25/04/2016 10:59 pm
Subject:    Re: Do transformation functions on RDD invoke a Job 
[sc.runJob]?



Spark SQL's query planner has always delayed building the RDD, so has 
never needed to eagerly calculate the range boundaries (since Spark 1.0).

On Mon, Apr 25, 2016 at 2:04 AM, Praveen Devarao <praveen...@in.ibm.com> 
wrote:
Thanks Reynold for the reason as to why sortBykey invokes a Job

When you say "DataFrame/Dataset does not have this issue" is it right to 
assume you are referring to Spark 2.0 or Spark 1.6 DF already has built-in 
it?

Thanking You
-
Praveen Devarao
Spark Technology Centre
IBM India Software Labs
-
"Courage doesn't always roar. Sometimes courage is the quiet voice at the 
end of the day saying I will try again"



From:Reynold Xin <r...@databricks.com>
To:Praveen Devarao/India/IBM@IBMIN
Cc:"d...@spark.apache.org" <d...@spark.apache.org>, user <
user@spark.apache.org>
Date:25/04/2016 11:26 am
Subject:Re: Do transformation functions on RDD invoke a Job 
[sc.runJob]?




Usually no - but sortByKey does because it needs the range boundary to be 
built in order to have the RDD. It is a long standing problem that's 
unfortunately very difficult to solve without breaking the RDD API.

In DataFrame/Dataset we don't have this issue though.


On Sun, Apr 24, 2016 at 10:54 PM, Praveen Devarao <praveen...@in.ibm.com> 
wrote:
Hi,

I have a streaming program with the block as below [ref: 
https://github.com/agsachin/streamingBenchmark/blob/master/spark-benchmarks/src/main/scala/TwitterStreaming.scala
]

1 val lines = messages.map(_._2)
2 val hashTags = lines.flatMap(status => status.split(" "
).filter(_.startsWith("#")))

3 val topCounts60 = hashTags.map((_, 1)).reduceByKey( _ + _ )
3a .map { case (topic, count) => (count, topic) }
3b .transform(_.sortByKey(false))

4atopCounts60.foreachRDD( rdd => {
4b val topList = rdd.take( 10 )
})

This batch is triggering 2 jobs...one at line 3b(sortByKey) and 
the other at 4b (rdd.take) I agree that there is a Job triggered on line 
4b as take() is an action on RDD while as on line 3b sortByKey is just a 
transformation function which as per docs is lazy evaluation...but I see 
that this line uses a RangePartitioner and Rangepartitioner on 
initialization invokes a method called sketch() that invokes collect() 
triggering a Job.

My question: Is it expected that sortByKey will invoke a Job...if 
yes, why is sortByKey listed as a transformation and not action. Are there 
any other functions like this that invoke a Job, though they are 
transformations and not actions?

I am on Spark 1.6

Thanking You
-
Praveen Devarao
Spark Technology Centre
IBM India Software Labs
-
"Courage doesn't always roar. Sometimes courage is the quiet voice at the 
end of the day saying I will try again"

Re: Do transformation functions on RDD invoke a Job [sc.runJob]?

[Michael Armbrust]

Spark SQL's query planner has always delayed building the RDD, so has never
needed to eagerly calculate the range boundaries (since Spark 1.0).

On Mon, Apr 25, 2016 at 2:04 AM, Praveen Devarao <praveen...@in.ibm.com>
wrote:

> Thanks Reynold for the reason as to why sortBykey invokes a Job
>
> When you say "DataFrame/Dataset does not have this issue" is it right to
> assume you are referring to Spark 2.0 or Spark 1.6 DF already has built-in
> it?
>
> Thanking You
>
> -
> Praveen Devarao
> Spark Technology Centre
> IBM India Software Labs
>
> -
> "Courage doesn't always roar. Sometimes courage is the quiet voice at the
> end of the day saying I will try again"
>
>
>
> From:Reynold Xin <r...@databricks.com>
> To:Praveen Devarao/India/IBM@IBMIN
> Cc:"d...@spark.apache.org" <d...@spark.apache.org>, user <
> user@spark.apache.org>
> Date:25/04/2016 11:26 am
> Subject:Re: Do transformation functions on RDD invoke a Job
> [sc.runJob]?
> --
>
>
>
> Usually no - but sortByKey does because it needs the range boundary to be
> built in order to have the RDD. It is a long standing problem that's
> unfortunately very difficult to solve without breaking the RDD API.
>
> In DataFrame/Dataset we don't have this issue though.
>
>
> On Sun, Apr 24, 2016 at 10:54 PM, Praveen Devarao <*praveen...@in.ibm.com*
> <praveen...@in.ibm.com>> wrote:
> Hi,
>
> I have a streaming program with the block as below [ref:
> *https://github.com/agsachin/streamingBenchmark/blob/master/spark-benchmarks/src/main/scala/TwitterStreaming.scala*
> <https://github.com/agsachin/streamingBenchmark/blob/master/spark-benchmarks/src/main/scala/TwitterStreaming.scala>
> ]
>
> *1 val **lines *= *messages*.map(_._2)
> *2 val **hashTags *= *lines*.flatMap(status => status.split(*" "*
> ).filter(_.startsWith(*"#"*)))
>
> *3 val **topCounts60 *= *hashTags*.map((_, 1)).reduceByKey( _ + _ )
> *3a* .map { *case *(topic, count) => (count, topic) }
> *3b* .transform(_.sortByKey(*false*))
>
> *4a**topCounts60*.foreachRDD( rdd => {
> *4b* *val *topList = rdd.take( 10 )
> })
>
> This batch is triggering 2 jobs...one at line *3b**(sortByKey)* and
> the other at *4b (rdd.take) *I agree that there is a Job triggered on
> line 4b as take() is an action on RDD while as on line 3b sortByKey is just
> a transformation function which as per docs is lazy evaluation...but I see
> that this line uses a RangePartitioner and Rangepartitioner on
> initialization invokes a method called *sketch() *that invokes *collect()*
> triggering a Job.
>
> My question: Is it expected that sortByKey will invoke a Job...if
> yes, why is sortByKey listed as a transformation and not action. Are there
> any other functions like this that invoke a Job, though they are
> transformations and not actions?
>
> I am on Spark 1.6
>
> Thanking You
>
> -
> Praveen Devarao
> Spark Technology Centre
> IBM India Software Labs
>
> -
> "Courage doesn't always roar. Sometimes courage is the quiet voice at the
> end of the day saying I will try again"
>
>
>
>

Re: Do transformation functions on RDD invoke a Job [sc.runJob]?

[Praveen Devarao]

Thanks Reynold for the reason as to why sortBykey invokes a Job

When you say "DataFrame/Dataset does not have this issue" is it right to 
assume you are referring to Spark 2.0 or Spark 1.6 DF already has built-in 
it?

Thanking You
-
Praveen Devarao
Spark Technology Centre
IBM India Software Labs
-
"Courage doesn't always roar. Sometimes courage is the quiet voice at the 
end of the day saying I will try again"



From:   Reynold Xin <r...@databricks.com>
To: Praveen Devarao/India/IBM@IBMIN
Cc: "d...@spark.apache.org" <d...@spark.apache.org>, user 
<user@spark.apache.org>
Date:   25/04/2016 11:26 am
Subject:    Re: Do transformation functions on RDD invoke a Job 
[sc.runJob]?



Usually no - but sortByKey does because it needs the range boundary to be 
built in order to have the RDD. It is a long standing problem that's 
unfortunately very difficult to solve without breaking the RDD API.

In DataFrame/Dataset we don't have this issue though.


On Sun, Apr 24, 2016 at 10:54 PM, Praveen Devarao <praveen...@in.ibm.com> 
wrote:
Hi,

I have a streaming program with the block as below [ref: 
https://github.com/agsachin/streamingBenchmark/blob/master/spark-benchmarks/src/main/scala/TwitterStreaming.scala
]

1 val lines = messages.map(_._2)
2 val hashTags = lines.flatMap(status => status.split(" "
).filter(_.startsWith("#")))

3 val topCounts60 = hashTags.map((_, 1)).reduceByKey( _ + _ )
3a .map { case (topic, count) => (count, topic) }
3b .transform(_.sortByKey(false))

4atopCounts60.foreachRDD( rdd => {
4b val topList = rdd.take( 10 )
})

This batch is triggering 2 jobs...one at line 3b(sortByKey)  and 
the other at 4b (rdd.take) I agree that there is a Job triggered on line 
4b as take() is an action on RDD while as on line 3b sortByKey is just a 
transformation function which as per docs is lazy evaluation...but I see 
that this line uses a RangePartitioner and Rangepartitioner on 
initialization invokes a method called sketch() that invokes collect() 
triggering a Job.

My question: Is it expected that sortByKey will invoke a Job...if 
yes, why is sortByKey listed as a transformation and not action. Are there 
any other functions like this that invoke a Job, though they are 
transformations and not actions?

I am on Spark 1.6

Thanking You
-
Praveen Devarao
Spark Technology Centre
IBM India Software Labs
-
"Courage doesn't always roar. Sometimes courage is the quiet voice at the 
end of the day saying I will try again"

Do transformation functions on RDD invoke a Job [sc.runJob]?

[Praveen Devarao]

Hi,

I have a streaming program with the block as below [ref: 
https://github.com/agsachin/streamingBenchmark/blob/master/spark-benchmarks/src/main/scala/TwitterStreaming.scala
]

1 val lines = messages.map(_._2)
2 val hashTags = lines.flatMap(status => status.split(" "
).filter(_.startsWith("#")))

3 val topCounts60 = hashTags.map((_, 1)).reduceByKey( _ + _ )
3a  .map { case (topic, count) => (count, topic) }
3b  .transform(_.sortByKey(false))

4a topCounts60.foreachRDD( rdd => {
4b  val topList = rdd.take( 10 )
})

This batch is triggering 2 jobs...one at line 3b (sortByKey)  and 
the other at 4b (rdd.take) I agree that there is a Job triggered on line 
4b as take() is an action on RDD while as on line 3b sortByKey is just a 
transformation function which as per docs is lazy evaluation...but I see 
that this line uses a RangePartitioner and Rangepartitioner on 
initialization invokes a method called sketch() that invokes collect() 
triggering a Job.

My question: Is it expected that sortByKey will invoke a Job...if 
yes, why is sortByKey listed as a transformation and not action. Are there 
any other functions like this that invoke a Job, though they are 
transformations and not actions?

I am on Spark 1.6

Thanking You
-
Praveen Devarao
Spark Technology Centre
IBM India Software Labs
-
"Courage doesn't always roar. Sometimes courage is the quiet voice at the 
end of the day saying I will try again"

Re: Do transformation functions on RDD invoke a Job [sc.runJob]?

[Reynold Xin]

Usually no - but sortByKey does because it needs the range boundary to be
built in order to have the RDD. It is a long standing problem that's
unfortunately very difficult to solve without breaking the RDD API.

In DataFrame/Dataset we don't have this issue though.


On Sun, Apr 24, 2016 at 10:54 PM, Praveen Devarao 
wrote:

> Hi,
>
> I have a streaming program with the block as below [ref:
> https://github.com/agsachin/streamingBenchmark/blob/master/spark-benchmarks/src/main/scala/TwitterStreaming.scala
> ]
>
> *1 val **lines *= *messages*.map(_._2)
> *2 val **hashTags *= *lines*.flatMap(status => status.split(*" "*
> ).filter(_.startsWith(*"#"*)))
>
> *3 val **topCounts60 *= *hashTags*.map((_, 1)).reduceByKey( _ + _ )
> *3a* .map { *case *(topic, count) => (count, topic) }
> *3b* .transform(_.sortByKey(*false*))
>
> *4a**topCounts60*.foreachRDD( rdd => {
> *4b* *val *topList = rdd.take( 10 )
> })
>
> This batch is triggering 2 jobs...one at line *3b**(sortByKey)*
>  and the other at *4b (rdd.take) *I agree that there is a Job triggered
> on line 4b as take() is an action on RDD while as on line 3b sortByKey is
> just a transformation function which as per docs is lazy evaluation...but I
> see that this line uses a RangePartitioner and Rangepartitioner on
> initialization invokes a method called *sketch() *that invokes *collect()*
> triggering a Job.
>
> My question: Is it expected that sortByKey will invoke a Job...if
> yes, why is sortByKey listed as a transformation and not action. Are there
> any other functions like this that invoke a Job, though they are
> transformations and not actions?
>
> I am on Spark 1.6
>
> Thanking You
>
> -
> Praveen Devarao
> Spark Technology Centre
> IBM India Software Labs
>
> -
> "Courage doesn't always roar. Sometimes courage is the quiet voice at the
> end of the day saying I will try again"
>