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Posted to user@spark.apache.org by chen yong <cy...@hotmail.com> on 2016/09/18 09:47:14 UTC
答复: 答复: it does not stop at breakpoints which is in an anonymous function
Dear Dirceu,
Below is our testing codes, as you can see, we have used "reduce" action to evoke evaluation. However, it still did not stop at breakpoint-1(as shown in the the code snippet) when debugging.
We are using IDEA version 14.0.3 to debug. It very very strange to us. Please help us(me and my colleagues).
// scalastyle:off println
package org.apache.spark.examples
import scala.math.random
import org.apache.spark._
import scala.util.logging.Logged
/** Computes an approximation to pi */
object SparkPi{
def main(args: Array[String]) {
val conf = new SparkConf().setAppName("Spark Pi").setMaster("local")
val spark = new SparkContext(conf)
val slices = if (args.length > 0) args(0).toInt else 2
val n = math.min(100000L * slices, Int.MaxValue).toInt // avoid overflow
val count = spark.parallelize(1 until n, slices).map { i =>
val x = random * 2 - 1 (breakpoint-1)
val y = random * 2 - 1
if (x*x + y*y < 1) 1 else 0
}.reduce(_ + _)
println("Pi is roughly " + 4.0 * count / (n - 1))
spark.stop()
}
}
________________________________
发件人: Dirceu Semighini Filho <di...@gmail.com>
发送时间: 2016年9月16日 22:27
收件人: chen yong
抄送: user@spark.apache.org
主题: Re: 答复: it does not stop at breakpoints which is in an anonymous function
No, that's not the right way of doing it.
Remember that RDD operations are lazy, due to performance reasons. Whenever you call one of those operation methods (count, reduce, collect, ...) they will execute all the functions that you have done to create that RDD.
It would help if you can post your code here, and also the way that you are executing it, and trying to debug.
2016-09-16 11:23 GMT-03:00 chen yong <cy...@hotmail.com>>:
Also, I wonder what is the right way to debug spark program. If I use ten anonymous function in one spark program, for debugging each of them, i have to place a COUNT action in advace and then remove it after debugging. Is that the right way?
________________________________
发件人: Dirceu Semighini Filho <di...@gmail.com>>
发送时间: 2016年9月16日 21:07
收件人: chen yong
抄送: user@spark.apache.org<ma...@spark.apache.org>
主题: Re: 答复: 答复: 答复: 答复: t it does not stop at breakpoints which is in an anonymous function
Hello Felix,
No, this line isn't the one that is triggering the execution of the function, the count does that, unless your count val is a lazy val.
The count method is the one that retrieves the information of the rdd, it has do go through all of it's data do determine how many records the RDD has.
Regards,
2016-09-15 22:23 GMT-03:00 chen yong <cy...@hotmail.com>>:
Dear Dirceu,
Thanks for your kind help.
i cannot see any code line corresponding to "..... retrieve the data from your DataFrame/RDDs....". which you suggested in the previous replies.
Later, I guess
the line
val test = count
is the key point. without it, it would not stop at the breakpont-1, right?
________________________________
发件人: Dirceu Semighini Filho <di...@gmail.com>>
发送时间: 2016年9月16日 0:39
收件人: chen yong
抄送: user@spark.apache.org<ma...@spark.apache.org>
主题: Re: 答复: 答复: 答复: t it does not stop at breakpoints which is in an anonymous function
Hi Felix,
Are sure your n is greater than 0?
Here it stops first at breakpoint 1, image attached.
Have you got the count to see if it's also greater than 0?
2016-09-15 11:41 GMT-03:00 chen yong <cy...@hotmail.com>>:
Dear Dirceu
Thank you for your help.
Acutally, I use Intellij IDEA to dubug the spark code.
Let me use the following code snippet to illustrate my problem. In the code lines below, I've set two breakpoints, breakpoint-1 and breakpoint-2. when i debuged the code, it did not stop at breakpoint-1, it seems that the map
function was skipped and it directly reached and stoped at the breakpoint-2.
Additionally, I find the following two posts
(1)http://stackoverflow.com/questions/29208844/apache-spark-logging-within-scala
(2)https://www.mail-archive.com/user@spark.apache.org/msg29010.html
I am wondering whether loggin is an alternative approach to debugging spark anonymous functions.
val count = spark.parallelize(1 to n, slices).map { i =>
val x = random * 2 - 1
val y = random * 2 - 1 (breakpoint-1 set in this line)
if (x*x + y*y < 1) 1 else 0
}.reduce(_ + _)
val test = x (breakpoint-2 set in this line)
________________________________
发件人: Dirceu Semighini Filho <di...@gmail.com>>
发送时间: 2016年9月14日 23:32
收件人: chen yong
主题: Re: 答复: 答复: t it does not stop at breakpoints which is in an anonymous function
I don't know which IDE do you use. I use Intellij, and here there is an Evaluate Expression dialog where I can execute code, whenever it has stopped in a breakpoint.
In eclipse you have watch and inspect where you can do the same.
Probably you are not seeing the debug stop in your functions because you never retrieve the data from your DataFrame/RDDs.
What are you doing with this function? Are you getting the result of this RDD/Dataframe at some place?
You can add a count after the function that you want to debug, just for debug, but don't forget to remove this after testing.
2016-09-14 12:20 GMT-03:00 chen yong <cy...@hotmail.com>>:
Dear Dirceu,
thanks you again.
Actually,I never saw it stopped at the breakpoints no matter how long I wait. It just skipped the whole anonymous function to direactly reach the first breakpoint immediately after the anonymous function body. Is that normal? I suspect sth wrong in my debugging operations or settings. I am very new to spark and scala.
Additionally, please give me some detailed instructions about "....Some ides provide you a place where you can execute the code to see it's results....". where is the PLACE
your help badly needed!
________________________________
发件人: Dirceu Semighini Filho <di...@gmail.com>>
发送时间: 2016年9月14日 23:07
收件人: chen yong
主题: Re: 答复: t it does not stop at breakpoints which is in an anonymous function
You can call a count in the ide just to debug, or you can wait until it reaches the code, so you can debug.
Some ides provide you a place where you can execute the code to see it's results.
Be aware of not adding this operations in your production code, because they can slow down the execution of your code.
2016-09-14 11:43 GMT-03:00 chen yong <cy...@hotmail.com>>:
Thanks for your reply.
you mean i have to insert some codes, such as xxxxx.count or xxxxx.collect, between the original spark code lines to invoke some operations, right?
but, where is the right places to put my code lines?
Felix
________________________________
发件人: Dirceu Semighini Filho <di...@gmail.com>>
发送时间: 2016年9月14日 22:33
收件人: chen yong
抄送: user@spark.apache.org<ma...@spark.apache.org>
主题: Re: t it does not stop at breakpoints which is in an anonymous function
Hello Felix,
Spark functions run lazy, and that's why it doesn't stop in those breakpoints.
They will be executed only when you call some methods of your dataframe/rdd, like the count, collect, ...
Regards,
Dirceu
2016-09-14 11:26 GMT-03:00 chen yong <cy...@hotmail.com>>:
Hi all,
I am newbie to spark. I am learning spark by debugging the spark code. It is strange to me that it does not stop at breakpoints which is in an anonymous function, it is normal in ordianry function, though. It that normal. How to obverse variables in an anonymous function.
Please help me. Thanks in advance!
Felix
Re: 答复: 答复: it does not stop at breakpoints which is in an anonymous function
Posted by Dirceu Semighini Filho <di...@gmail.com>.
Hi Felix,
Just runned your code and it prints
Pi is roughly 4.0
Here is the code that I used as you didn't show what a random is I used the
nextInt()
val n = math.min(100000L * slices, Int.MaxValue).toInt // avoid overflow
val count = context.sparkContext.parallelize(1 until n, slices).map { i
=>
val random = new scala.util.Random(1000).nextInt()
val x = random * 2 - 1 //(breakpoint-1)
val y = random * 2 - 1
if (x*x + y*y < 1) 1 else 0
}.reduce(_ + _)
println("Pi is roughly " + 4.0 * count / (n - 1))
context.sparkContext.stop()
Also using the debug it stops into the map (breakpoint 1) before going to
print
2016-09-18 6:47 GMT-03:00 chen yong <cy...@hotmail.com>:
> Dear Dirceu,
>
>
> Below is our testing codes, as you can see, we have used "reduce" action
> to evoke evaluation. However, it still did not stop at breakpoint-1(as
> shown in the the code snippet) when debugging.
>
>
>
> We are using IDEA version 14.0.3 to debug. It very very strange to us.
> Please help us(me and my colleagues).
>
>
> // scalastyle:off println
> package org.apache.spark.examples
> import scala.math.random
> import org.apache.spark._
> import scala.util.logging.Logged
>
> /** Computes an approximation to pi */
> object SparkPi{
> def main(args: Array[String]) {
>
> val conf = new SparkConf().setAppName("Spark Pi").setMaster("local")
> val spark = new SparkContext(conf)
> val slices = if (args.length > 0) args(0).toInt else 2
> val n = math.min(100000L * slices, Int.MaxValue).toInt // avoid
> overflow
> val count = spark.parallelize(1 until n, slices).map { i =>
> val x = random * 2 - 1 (breakpoint-1)
> val y = random * 2 - 1
> if (x*x + y*y < 1) 1 else 0
> }.reduce(_ + _)
> println("Pi is roughly " + 4.0 * count / (n - 1))
> spark.stop()
> }
> }
>
>
>
>
> ------------------------------
> *发件人:* Dirceu Semighini Filho <di...@gmail.com>
> *发送时间:* 2016年9月16日 22:27
> *收件人:* chen yong
> *抄送:* user@spark.apache.org
> *主题:* Re: 答复: it does not stop at breakpoints which is in an anonymous
> function
>
> No, that's not the right way of doing it.
> Remember that RDD operations are lazy, due to performance reasons.
> Whenever you call one of those operation methods (count, reduce, collect,
> ...) they will execute all the functions that you have done to create that
> RDD.
> It would help if you can post your code here, and also the way that you
> are executing it, and trying to debug.
>
>
> 2016-09-16 11:23 GMT-03:00 chen yong <cy...@hotmail.com>:
>
>> Also, I wonder what is the right way to debug spark program. If I use
>> ten anonymous function in one spark program, for debugging each of them, i
>> have to place a COUNT action in advace and then remove it after debugging.
>> Is that the right way?
>>
>>
>> ------------------------------
>> *发件人:* Dirceu Semighini Filho <di...@gmail.com>
>> *发送时间:* 2016年9月16日 21:07
>> *收件人:* chen yong
>> *抄送:* user@spark.apache.org
>> *主题:* Re: 答复: 答复: 答复: 答复: t it does not stop at breakpoints which is in
>> an anonymous function
>>
>> Hello Felix,
>> No, this line isn't the one that is triggering the execution of the
>> function, the count does that, unless your count val is a lazy val.
>> The count method is the one that retrieves the information of the rdd, it
>> has do go through all of it's data do determine how many records the RDD
>> has.
>>
>> Regards,
>>
>> 2016-09-15 22:23 GMT-03:00 chen yong <cy...@hotmail.com>:
>>
>>>
>>> Dear Dirceu,
>>>
>>> Thanks for your kind help.
>>> i cannot see any code line corresponding to "..... retrieve the data
>>> from your DataFrame/RDDs....". which you suggested in the previous replies.
>>>
>>> Later, I guess
>>>
>>> the line
>>>
>>> val test = count
>>>
>>> is the key point. without it, it would not stop at the breakpont-1,
>>> right?
>>>
>>>
>>>
>>> ------------------------------
>>> *发件人:* Dirceu Semighini Filho <di...@gmail.com>
>>> *发送时间:* 2016年9月16日 0:39
>>> *收件人:* chen yong
>>> *抄送:* user@spark.apache.org
>>> *主题:* Re: 答复: 答复: 答复: t it does not stop at breakpoints which is in an
>>> anonymous function
>>>
>>> Hi Felix,
>>> Are sure your n is greater than 0?
>>> Here it stops first at breakpoint 1, image attached.
>>> Have you got the count to see if it's also greater than 0?
>>>
>>> 2016-09-15 11:41 GMT-03:00 chen yong <cy...@hotmail.com>:
>>>
>>>> Dear Dirceu
>>>>
>>>>
>>>> Thank you for your help.
>>>>
>>>>
>>>> Acutally, I use Intellij IDEA to dubug the spark code.
>>>>
>>>>
>>>> Let me use the following code snippet to illustrate my problem. In the
>>>> code lines below, I've set two breakpoints, breakpoint-1 and breakpoint-2.
>>>> when i debuged the code, it did not stop at breakpoint-1, it seems
>>>> that the map
>>>>
>>>> function was skipped and it directly reached and stoped at the
>>>> breakpoint-2.
>>>>
>>>> Additionally, I find the following two posts
>>>> (1)http://stackoverflow.com/questions/29208844/apache-spark-
>>>> logging-within-scala
>>>> (2)https://www.mail-archive.com/user@spark.apache.org/msg29010.html
>>>>
>>>> I am wondering whether loggin is an alternative approach to debugging
>>>> spark anonymous functions.
>>>>
>>>>
>>>> val count = spark.parallelize(1 to n, slices).map { i =>
>>>> val x = random * 2 - 1
>>>> val y = random * 2 - 1 (breakpoint-1 set in this line)
>>>> if (x*x + y*y < 1) 1 else 0
>>>> }.reduce(_ + _)
>>>> val test = x (breakpoint-2 set in this line)
>>>>
>>>>
>>>>
>>>> ------------------------------
>>>> *发件人:* Dirceu Semighini Filho <di...@gmail.com>
>>>> *发送时间:* 2016年9月14日 23:32
>>>> *收件人:* chen yong
>>>> *主题:* Re: 答复: 答复: t it does not stop at breakpoints which is in an
>>>> anonymous function
>>>>
>>>> I don't know which IDE do you use. I use Intellij, and here there is an
>>>> Evaluate Expression dialog where I can execute code, whenever it has
>>>> stopped in a breakpoint.
>>>> In eclipse you have watch and inspect where you can do the same.
>>>> Probably you are not seeing the debug stop in your functions because
>>>> you never retrieve the data from your DataFrame/RDDs.
>>>> What are you doing with this function? Are you getting the result of
>>>> this RDD/Dataframe at some place?
>>>> You can add a count after the function that you want to debug, just for
>>>> debug, but don't forget to remove this after testing.
>>>>
>>>>
>>>>
>>>> 2016-09-14 12:20 GMT-03:00 chen yong <cy...@hotmail.com>:
>>>>
>>>>> Dear Dirceu,
>>>>>
>>>>>
>>>>> thanks you again.
>>>>>
>>>>>
>>>>> Actually,I never saw it stopped at the breakpoints no matter how long
>>>>> I wait. It just skipped the whole anonymous function to
>>>>> direactly reach the first breakpoint immediately after the anonymous
>>>>> function body. Is that normal? I suspect sth wrong in my debugging
>>>>> operations or settings. I am very new to spark and scala.
>>>>>
>>>>>
>>>>> Additionally, please give me some detailed instructions about "....Some
>>>>> ides provide you a place where you can execute the code to see it's
>>>>> results....". where is the PLACE
>>>>>
>>>>>
>>>>> your help badly needed!
>>>>>
>>>>>
>>>>> ------------------------------
>>>>> *发件人:* Dirceu Semighini Filho <di...@gmail.com>
>>>>> *发送时间:* 2016年9月14日 23:07
>>>>> *收件人:* chen yong
>>>>> *主题:* Re: 答复: t it does not stop at breakpoints which is in an
>>>>> anonymous function
>>>>>
>>>>> You can call a count in the ide just to debug, or you can wait until
>>>>> it reaches the code, so you can debug.
>>>>> Some ides provide you a place where you can execute the code to see
>>>>> it's results.
>>>>> Be aware of not adding this operations in your production code,
>>>>> because they can slow down the execution of your code.
>>>>>
>>>>>
>>>>>
>>>>> 2016-09-14 11:43 GMT-03:00 chen yong <cy...@hotmail.com>:
>>>>>
>>>>>>
>>>>>> Thanks for your reply.
>>>>>>
>>>>>> you mean i have to insert some codes, such as xxxxx.count or
>>>>>> xxxxx.collect, between the original spark code lines to invoke some
>>>>>> operations, right?
>>>>>> but, where is the right places to put my code lines?
>>>>>>
>>>>>> Felix
>>>>>>
>>>>>> ------------------------------
>>>>>> *发件人:* Dirceu Semighini Filho <di...@gmail.com>
>>>>>> *发送时间:* 2016年9月14日 22:33
>>>>>> *收件人:* chen yong
>>>>>> *抄送:* user@spark.apache.org
>>>>>> *主题:* Re: t it does not stop at breakpoints which is in an anonymous
>>>>>> function
>>>>>>
>>>>>> Hello Felix,
>>>>>> Spark functions run lazy, and that's why it doesn't stop in those
>>>>>> breakpoints.
>>>>>> They will be executed only when you call some methods of your
>>>>>> dataframe/rdd, like the count, collect, ...
>>>>>>
>>>>>> Regards,
>>>>>> Dirceu
>>>>>>
>>>>>> 2016-09-14 11:26 GMT-03:00 chen yong <cy...@hotmail.com>:
>>>>>>
>>>>>>> Hi all,
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> I am newbie to spark. I am learning spark by debugging the
>>>>>>> spark code. It is strange to me that it does not stop at breakpoints which
>>>>>>> is in an anonymous function, it is normal in ordianry function,
>>>>>>> though. It that normal. How to obverse variables in an anonymous
>>>>>>> function.
>>>>>>>
>>>>>>>
>>>>>>> Please help me. Thanks in advance!
>>>>>>>
>>>>>>>
>>>>>>> Felix
>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>