I just merged the PR https://github.com/apache/arrow-testing/pull/11
Various aspects of this make me uncomfortable so I hope they can be addressed in follow up work On Thu, Oct 10, 2019 at 5:41 AM Renjie Liu <liurenjie2...@gmail.com> wrote: > > I've create ticket to track here: > https://issues.apache.org/jira/browse/ARROW-6845 > > For this moment, can we check in those pregenerated data to unblock rust > version's arrow reader? > > On Thu, Oct 10, 2019 at 1:20 PM Renjie Liu <liurenjie2...@gmail.com> wrote: > > > It would be fine in that case. > > > > Wes McKinney <wesmck...@gmail.com> 于 2019年10月10日周四 下午12:58写道： > > > >> On Wed, Oct 9, 2019 at 10:16 PM Renjie Liu <liurenjie2...@gmail.com> > >> wrote: > >> > > >> > 1. There already exists a low level parquet writer which can produce > >> > parquet file, so unit test should be fine. But writer from arrow to > >> parquet > >> > doesn't exist yet, and it may take some period of time to finish it. > >> > 2. In fact my data are randomly generated and it's definitely > >> reproducible. > >> > However, I don't think it would be good idea to randomly generate data > >> > everytime we run ci because it would be difficult to debug. For example > >> PR > >> > a introduced a bug, which is triggerred in other PR's build it would be > >> > confusing for contributors. > >> > >> Presumably any random data generation would use a fixed seed precisely > >> to be reproducible. > >> > >> > 3. I think it would be good idea to spend effort on integration test > >> with > >> > parquet because it's an important use case of arrow. Also similar > >> approach > >> > could be extended to other language and other file format(avro, orc). > >> > > >> > > >> > On Wed, Oct 9, 2019 at 11:08 PM Wes McKinney <wesmck...@gmail.com> > >> wrote: > >> > > >> > > There are a number of issues worth discussion. > >> > > > >> > > 1. What is the timeline/plan for Rust implementing a Parquet _writer_? > >> > > It's OK to be reliant on other libraries in the short term to produce > >> > > files to test against, but does not strike me as a sustainable > >> > > long-term plan. Fixing bugs can be a lot more difficult than it needs > >> > > to be if you can't write targeted "endogenous" unit tests > >> > > > >> > > 2. Reproducible data generation > >> > > > >> > > I think if you're going to test against a pre-generated corpus, you > >> > > should make sure that generating the corpus is reproducible for other > >> > > developers (i.e. with a Dockerfile), and can be extended by adding new > >> > > files or random data generation. > >> > > > >> > > I additionally would prefer generating the test corpus at test time > >> > > rather than checking in binary files. If this isn't viable right now > >> > > we can create an "arrow-rust-crutch" git repository for you to stash > >> > > binary files until some of these testing scalability issues are > >> > > addressed. > >> > > > >> > > If we're going to spend energy on Parquet integration testing with > >> > > Java, this would be a good opportunity to do the work in a way where > >> > > the C++ Parquet library can also participate (since we ought to be > >> > > doing integration tests with Java, and we can also read JSON files to > >> > > Arrow). > >> > > > >> > > On Tue, Oct 8, 2019 at 11:54 PM Renjie Liu <liurenjie2...@gmail.com> > >> > > wrote: > >> > > > > >> > > > On Wed, Oct 9, 2019 at 12:11 PM Andy Grove <andygrov...@gmail.com> > >> > > wrote: > >> > > > > >> > > > > I'm very interested in helping to find a solution to this because > >> we > >> > > really > >> > > > > do need integration tests for Rust to make sure we're compatible > >> with > >> > > other > >> > > > > implementations... there is also the ongoing CI dockerization work > >> > > that I > >> > > > > feel is related. > >> > > > > > >> > > > > I haven't looked at the current integration tests yet and would > >> > > appreciate > >> > > > > some pointers on how all of this works (do we have docs?) or > >> where to > >> > > start > >> > > > > looking. > >> > > > > > >> > > > I have a test in my latest PR: > >> https://github.com/apache/arrow/pull/5523 > >> > > > And here is the generated data: > >> > > > https://github.com/apache/arrow-testing/pull/11 > >> > > > As with program to generate these data, it's just a simple java > >> program. > >> > > > I'm not sure whether we need to integrate it into arrow. > >> > > > > >> > > > > > >> > > > > I imagine the integration test could follow the approach that > >> Renjie is > >> > > > > outlining where we call Java to generate some files and then call > >> Rust > >> > > to > >> > > > > parse them? > >> > > > > > >> > > > > Thanks, > >> > > > > > >> > > > > Andy. > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > > >> > > > > On Tue, Oct 8, 2019 at 9:48 PM Renjie Liu < > >> liurenjie2...@gmail.com> > >> > > wrote: > >> > > > > > >> > > > > > Hi: > >> > > > > > > >> > > > > > I'm developing rust version of reader which reads parquet into > >> arrow > >> > > > > array. > >> > > > > > To verify the correct of this reader, I use the following > >> approach: > >> > > > > > > >> > > > > > > >> > > > > > 1. Define schema with protobuf. > >> > > > > > 2. Generate json data of this schema using other language > >> with > >> > > more > >> > > > > > sophisticated implementation (e.g. java) > >> > > > > > 3. Generate parquet data of this schema using other language > >> with > >> > > more > >> > > > > > sophisticated implementation (e.g. java) > >> > > > > > 4. Write tests to read json file, and parquet file into > >> memory > >> > > (arrow > >> > > > > > array), then compare json data with arrow data. > >> > > > > > > >> > > > > > I think with this method we can guarantee the correctness of > >> arrow > >> > > > > reader > >> > > > > > because json format is ubiquitous and their implementation are > >> more > >> > > > > stable. > >> > > > > > > >> > > > > > Any comment is appreciated. > >> > > > > > > >> > > > > > >> > > > > >> > > > > >> > > > -- > >> > > > Renjie Liu > >> > > > Software Engineer, MVAD > >> > > > >> > > >> > > >> > -- > >> > Renjie Liu > >> > Software Engineer, MVAD > >> > > > > -- > Renjie Liu > Software Engineer, MVAD
