Jörn, I'm interested in your point on coverage. Coverage has been a useful tool for highlighting areas in the codebase that pose a source of potential risk. However, generally speaking, I've found that traditional coverage tools do not provide useful information when applied to distributed data processing frameworks. Here the code is mostly constructional, comprising calls to factories, constructors, and the like, and resulting in a representation of a job that will be executed later on, in some other environment. One could attain high levels of coverage simply by building the pipeline and not submitting it. Certainly it is easy measure coverage on individual transforms, but for jobs/pipelines it seems somewhat more illusive.
I'd be keen to hear of your experiences and approaches in this regard as it sounds as though you are generating more useful coverage metrics. Personally I've been considering adopting a mutation-testing/chaos-monkey type approach to pipeline testing in an effort to ascertain which parts of a pipeline are not covered by a test suite. I describe it here, albeit for the purpose of reporting code coverage on Hive SQL statements: https://github.com/klarna/HiveRunner/issues/65#issuecomment-283785351 Thanks, Elliot. On 10 April 2017 at 15:32, Jörn Franke <jornfra...@gmail.com> wrote: > > I think in the end you need to check the coverage of your application. If > your application is well covered on the job or pipeline level (depends > however on how you implement these tests) then it can be fine. > In the end it really depends on the data and what kind of transformation > you implement. For example, you have 90% of your job with standard > transformations, but 10% are more or less complex customized functions, > then it might be worth to test the function with many different data inputs > as unit tests and have integrated job/pipeline tests in addition. > > On 10. Apr 2017, at 15:46, Gokula Krishnan D <email2...@gmail.com> wrote: > > Hello Shiv, > > Unit Testing is really helping when you follow TDD approach. And it's a > safe way to code a program locally and also you can make use those test > cases during the build process by using any of the continuous integration > tools ( Bamboo, Jenkins). If so you can ensure that artifacts are being > tested before deploying into Cluster. > > > Thanks & Regards, > Gokula Krishnan* (Gokul)* > > On Wed, Apr 5, 2017 at 7:32 AM, Shiva Ramagopal <tr.s...@gmail.com> wrote: > >> Hi, >> >> I've been following this thread for a while. >> >> I'm trying to bring in a test strategy in my team to test a number of >> data pipelines before production. I have watched Lars' presentation and >> find it great. However I'm debating whether unit tests are worth the effort >> if there are good job-level and pipeline-level tests. Does anybody have any >> experiences benefitting from unit-tests in such a case? >> >> Cheers, >> Shiv >> >> On Mon, Dec 12, 2016 at 6:00 AM, Juan Rodríguez Hortalá < >> juan.rodriguez.hort...@gmail.com> wrote: >> >>> Hi all, >>> >>> I would also would like to participate on that. >>> >>> Greetings, >>> >>> Juan >>> >>> On Fri, Dec 9, 2016 at 6:03 AM, Michael Stratton < >>> michael.strat...@komodohealth.com> wrote: >>> >>>> That sounds great, please include me so I can get involved. >>>> >>>> On Fri, Dec 9, 2016 at 7:39 AM, Marco Mistroni <mmistr...@gmail.com> >>>> wrote: >>>> >>>>> Me too as I spent most of my time writing unit/integ tests.... pls >>>>> advise on where I can start >>>>> Kr >>>>> >>>>> On 9 Dec 2016 12:15 am, "Miguel Morales" <therevolti...@gmail.com> >>>>> wrote: >>>>> >>>>>> I would be interested in contributing. Ive created my own library >>>>>> for this as well. In my blog post I talk about testing with Spark in >>>>>> RSpec >>>>>> style: >>>>>> https://medium.com/@therevoltingx/test-driven-development-w- >>>>>> apache-spark-746082b44941 >>>>>> >>>>>> Sent from my iPhone >>>>>> >>>>>> On Dec 8, 2016, at 4:09 PM, Holden Karau <hol...@pigscanfly.ca> >>>>>> wrote: >>>>>> >>>>>> There are also libraries designed to simplify testing Spark in the >>>>>> various platforms, spark-testing-base >>>>>> <http://github.com/holdenk/spark-testing-base> for Scala/Java/Python >>>>>> (& video https://www.youtube.com/watch?v=f69gSGSLGrY), sscheck >>>>>> <https://github.com/juanrh/sscheck> (scala focused property based), >>>>>> pyspark.test (python focused with py.test instead of unittest2) (& >>>>>> blog post from nextdoor https://engblog.nextd >>>>>> oor.com/unit-testing-apache-spark-with-py-test-3b8970dc013b# >>>>>> .jw3bdcej9 ) >>>>>> >>>>>> Good luck on your Spark Adventures :) >>>>>> >>>>>> P.S. >>>>>> >>>>>> If anyone is interested in helping improve spark testing libraries >>>>>> I'm always looking for more people to be involved with spark-testing-base >>>>>> because I'm lazy :p >>>>>> >>>>>> On Thu, Dec 8, 2016 at 2:05 PM, Lars Albertsson <la...@mapflat.com> >>>>>> wrote: >>>>>> >>>>>>> I wrote some advice in a previous post on the list: >>>>>>> http://markmail.org/message/bbs5acrnksjxsrrs >>>>>>> >>>>>>> It does not mention python, but the strategy advice is the same. Just >>>>>>> replace JUnit/Scalatest with pytest, unittest, or your favourite >>>>>>> python test framework. >>>>>>> >>>>>>> >>>>>>> I recently held a presentation on the subject. There is a video >>>>>>> recording at https://vimeo.com/192429554 and slides at >>>>>>> http://www.slideshare.net/lallea/test-strategies-for-data-pr >>>>>>> ocessing-pipelines-67244458 >>>>>>> >>>>>>> You can find more material on test strategies at >>>>>>> http://www.mapflat.com/lands/resources/reading-list/index.html >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> Lars Albertsson >>>>>>> Data engineering consultant >>>>>>> www.mapflat.com >>>>>>> https://twitter.com/lalleal >>>>>>> +46 70 7687109 >>>>>>> Calendar: https://goo.gl/6FBtlS, https://freebusy.io/lalle@mapf >>>>>>> lat.com >>>>>>> >>>>>>> >>>>>>> On Thu, Dec 8, 2016 at 4:14 PM, pseudo oduesp <pseudo20...@gmail.com> >>>>>>> wrote: >>>>>>> > somone can tell me how i can make unit test on pyspark ? >>>>>>> > (book, tutorial ...) >>>>>>> >>>>>>> ------------------------------------------------------------ >>>>>>> --------- >>>>>>> To unsubscribe e-mail: user-unsubscr...@spark.apache.org >>>>>>> >>>>>>> >>>>>> >>>>>> >>>>>> -- >>>>>> Cell : 425-233-8271 <(425)%20233-8271> >>>>>> Twitter: https://twitter.com/holdenkarau >>>>>> >>>>>> >>>> >>> >> >