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From Josh Wills <jwi...@cloudera.com>
Subject Re: Multiple Reduces in a Single Crunch Job
Date Thu, 04 Dec 2014 22:21:55 GMT
Danny,

Spent a couple of hours today banging on this by hacking on some
integration tests but couldn't replicate it. However, I just took a closer
look at the plan you posted, and I noticed that all of the files you are
writing out are prefixed w/ "hdfs:/" except for the /tmp/crunch-* file that
Crunch is creating; is it possible that Crunch is creating the temp file
locally on your client machine for some reason? I can't think of why that
would happen off the top of my head, but if that is the problem, I'll at
least be able to figure out where to look.

Josh


On Tue, Nov 25, 2014 at 6:30 PM, Danny Morgan <unluckyboy@hotmail.com>
wrote:

> No problem, Happy Thanksgiving!
>
> Gobble Gobble...
>
> ------------------------------
> From: jwills@cloudera.com
> Date: Tue, 25 Nov 2014 18:23:14 -0800
>
> Subject: Re: Multiple Reduces in a Single Crunch Job
> To: user@crunch.apache.org
>
> Very useful-- thank you. Will dig into it and report back, although I'm
> heading out for the holiday so it likely won't be until early next week.
>
> J
>
> On Tue, Nov 25, 2014 at 6:16 PM, Danny Morgan <unluckyboy@hotmail.com>
> wrote:
>
>  Having a single pipeline in the application didn't fix it. Sticking a
> pipeline.run() in the middle also didn't matter either, the plan appears
> such that the planner is completely ignoring the second the run() I added.
>
> However what DOES WORK is if I do:
>
> collection = secondarySort()
> pipeline.cache(collection)
> pipeline.run()
> newcollection = collection.groupByKey()
>
> If I try adding the cache() without calling run() in between it doesn't
> work. Hope that's enough info for you to fix the possible planner bug.
>
> Thanks for the help Josh!
>
> ------------------------------
> From: unluckyboy@hotmail.com
> To: user@crunch.apache.org
> Subject: RE: Multiple Reduces in a Single Crunch Job
> Date: Wed, 26 Nov 2014 01:58:11 +0000
>
>
> I tried doing a Sample() instead of identity function, but that got fused
> into the reduce as well and didn't work.
>
> First thing I tried was sticking a pipeline.run() in between there and I
> was surprised but it didn't work either, same error. I'll rerun that config
> now and try to get the dot files for the plan.
>
> Not sure if this is affecting it but in the same crunch application I have
> a completely independent pipeline the runs before this one executes. I'll
> turn that off as well and see if it's causing the issue.
>
> ------------------------------
> From: jwills@cloudera.com
> Date: Tue, 25 Nov 2014 17:43:52 -0800
> Subject: Re: Multiple Reduces in a Single Crunch Job
> To: user@crunch.apache.org
>
> Drat, I was hoping it was something simple. You could manually fix it by
> injecting a pipeline.run() call between the secondarySort and the
> groupByKey(), but of course, we'd like to handle this situation correctly
> by default.
>
> J
>
> On Tue, Nov 25, 2014 at 5:39 PM, Danny Morgan <unluckyboy@hotmail.com>
> wrote:
>
> I did a parallelDo with the IdentityFn of the output of the secondarySort
> and the IdentityFn was just fused into the reduce phase of the
> secondarySort and I got the same error message.
>
> I think you want me to somehow force a map phase in between the two
> reduces?
>
> -Danny
>
> ------------------------------
> From: josh.wills@gmail.com
> Date: Tue, 25 Nov 2014 17:23:29 -0800
>
> Subject: Re: Multiple Reduces in a Single Crunch Job
> To: user@crunch.apache.org
>
> Oh, dumb question-- if you put like a dummy function between the
> secondarySort and the groupByKey, like an IdentityFn or something, do
> things work again? That would help w/diagnosing the problem.
>
> On Tue, Nov 25, 2014 at 5:15 PM, Josh Wills <jwills@cloudera.com> wrote:
>
> So if you're getting it quickly, it might be b/c the job isn't recognizing
> the dependency between the two separate phases of the job for some reason
> (e.g., it's not realizing that one job has to be run before the other one.)
> That's an odd situation, but we have had bugs like that in the past; let me
> see if I can re-create the situation in an integration test. Which version
> of Crunch?
>
> J
>
> On Tue, Nov 25, 2014 at 4:40 PM, Danny Morgan <unluckyboy@hotmail.com>
> wrote:
>
> No that's definitely not it. I get this issue if I write to a single
> output as well.
>
> If I remove the groupByKey().combineValues() line and just write out the
> output from the SecondarySort it works. Seems to only complain about the
> temp path not existing when I have multiple reduce phases in the pipeline.
> Also the error seems to happen immediately during the setup or planning
> phase, I assume this because the yarn jobs get created but they don't do
> anything, and instead of FAILED the error message is "Application killed by
> user."
>
> -Danny
>
> ------------------------------
> From: jwills@cloudera.com
> Date: Tue, 25 Nov 2014 16:30:58 -0800
>
> Subject: Re: Multiple Reduces in a Single Crunch Job
> To: user@crunch.apache.org
>
> Ack, sorry-- it's this: https://issues.apache.org/jira/browse/CRUNCH-481
> <https://issues.apache.org/jira/browse/CRUNCH-481-->
>
> On Tue, Nov 25, 2014 at 4:24 PM, Danny Morgan <unluckyboy@hotmail.com>
> wrote:
>
> Hello Again Josh,
>
> The link to the Jira issue you sent out seems to be cut off, could you
> please resend it?
>
> I deleted the line where I write the collection to a text file, and
> retried it but it didn't work either. Also tried writing the collection out
> as Avro instead of Parquet, but got the same error.
>
> Here's the rest of the stracktrace:
>
> org.apache.hadoop.mapreduce.lib.input.InvalidInputException: Input path
> does not exist: hdfs:///tmp/crunch-2008950085/p1
>         at
> org.apache.hadoop.mapreduce.lib.input.FileInputFormat.listStatus(FileInputFormat.java:285)
>         at
> org.apache.hadoop.mapreduce.lib.input.CombineFileInputFormat.getSplits(CombineFileInputFormat.java:217)
>         at
> org.apache.crunch.impl.mr.run.CrunchInputFormat.getSplits(CrunchInputFormat.java:65)
>         at
> org.apache.hadoop.mapreduce.JobSubmitter.writeNewSplits(JobSubmitter.java:491)
>         at
> org.apache.hadoop.mapreduce.JobSubmitter.writeSplits(JobSubmitter.java:508)
>         at
> org.apache.hadoop.mapreduce.JobSubmitter.submitJobInternal(JobSubmitter.java:392)
>         at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1268)
>         at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1265)
>         at java.security.AccessController.doPrivileged(Native Method)
>         at javax.security.auth.Subject.doAs(Subject.java:415)
>         at
> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1528)
>         at org.apache.hadoop.mapreduce.Job.submit(Job.java:1265)
>         at
> org.apache.crunch.hadoop.mapreduce.lib.jobcontrol.CrunchControlledJob.submit(CrunchControlledJob.java:340)
>         at
> org.apache.crunch.hadoop.mapreduce.lib.jobcontrol.CrunchJobControl.startReadyJobs(CrunchJobControl.java:277)
>         at
> org.apache.crunch.hadoop.mapreduce.lib.jobcontrol.CrunchJobControl.pollJobStatusAndStartNewOnes(CrunchJobControl.java:316)
>         at
> org.apache.crunch.impl.mr.exec.MRExecutor.monitorLoop(MRExecutor.java:113)
>         at
> org.apache.crunch.impl.mr.exec.MRExecutor.access$000(MRExecutor.java:55)
>         at
> org.apache.crunch.impl.mr.exec.MRExecutor$1.run(MRExecutor.java:84)
>         at java.lang.Thread.run(Thread.java:744)
>
> Thanks Josh!
>
> ------------------------------
> From: jwills@cloudera.com
> Date: Tue, 25 Nov 2014 16:10:33 -0800
> Subject: Re: Multiple Reduces in a Single Crunch Job
> To: user@crunch.apache.org
>
>
> Hey Danny,
>
> I'm wondering if this is caused by
> https://issues.apache.org/jira/browse/CRUNCH-481-- I think we use
> different output committers for text files vs. parquet files, so at least
> one of the outputs won't be written properly-- does that make sense?
>
> Josh
>
> On Tue, Nov 25, 2014 at 4:07 PM, Danny Morgan <unluckyboy@hotmail.com>
> wrote:
>
> Hi Crunchers,
>
> I've attached a pdf of what my plan looks like. I've run into this problem
> before where I have multiple reduce steps chained together in a single
> pipeline and always get the same error.
>
> In the case of the attached pdf the error is "org.apache.hadoop.mapreduce.lib.input.InvalidInputException:
> Input path does not exist: hdfs:///tmp/crunch-1279941375/p1"
>
> That's the temp directory the crunch planner set up for the first reduce
> phase.
>
> Can I run multiple chained reduces within the same pipeline? Do I have to
> manually write out the output from the first reduce?
>
> Here's what the code looks like:
>
>       // Simple mapper
>       PTable<String, Pair<Long, Log>> first = Danny.filterForDanny(logs);
>       // Secondary sort happens here
>       PTable<Danny, Long> second = Danny.extractDannys(first);
>       // Regular group by
>       PTable<Danny, Long> third =
> second.groupByKey().combineValues(Aggregators.SUM_LONGS());
>       // simple function that populates some fields in the Danny object
> with the aggregate results
>       PCollection<Pair<Danny, String>> done = Danny.finalize(third);
>       Pair<PCollection<Danny>, PCollection<String>> splits =
> Channels.split(done);
>       splits.second().write(To.textFile(mypath, WriteMode.OVERWRITE);
>       Target pq_danny = new AvroParquetFileTarget(pqPath));
>       splits.first().write(pq_danny, WriteMode.OVERWRITE)
>
> Thanks!
>
> -Danny
>
>
>
>
> --
> Director of Data Science
> Cloudera <http://www.cloudera.com>
> Twitter: @josh_wills <http://twitter.com/josh_wills>
>
>
>
>
> --
> Director of Data Science
> Cloudera <http://www.cloudera.com>
> Twitter: @josh_wills <http://twitter.com/josh_wills>
>
>
>
>
> --
> Director of Data Science
> Cloudera <http://www.cloudera.com>
> Twitter: @josh_wills <http://twitter.com/josh_wills>
>
>
>
>
>
> --
> Director of Data Science
> Cloudera <http://www.cloudera.com>
> Twitter: @josh_wills <http://twitter.com/josh_wills>
>
>
>
>
> --
> Director of Data Science
> Cloudera <http://www.cloudera.com>
> Twitter: @josh_wills <http://twitter.com/josh_wills>
>



-- 
Director of Data Science
Cloudera <http://www.cloudera.com>
Twitter: @josh_wills <http://twitter.com/josh_wills>

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