Hadoop FileSystem and FileContext Workstream (2014)

In order to begin iterating on improving HCFS test coverage we need an unambiguous mechanism for implementing HCFS tests. After implementing HCFS tests, we want to compare test coverage with a gold-standard, and finally, where any gaps exist we want to be able to justify them using simplest semantics possible, ideally in code. The below three JIRAs address these 3 issues. Once they are completed, HCFS testing will be much simpler.

* HADOOP-9361: A programmatic way for FS implementations to broadcast the features they support, so that all file systems can reuse the same basic test libraries without needing to do ad-hoc overriding of certain implementations.

* HADOOP-10463: Boosting RawLocalFileSystem test coverage and

* HADOOP-10461: Creating an injection framework for any HCFS to plug into, which supports: (feed back pending from OrangeFS Community and others).

* BIGTOP-1089: Scale testing as a universal HCFS integration test, confirming that the whole ecosystem works together on FS interface level. (Scale testing / updateing to 50 input splits pending from OrangeFS community).

In another thread, we will work to improve coverage of RawLocalFileSystem (LocalFs/LocalFileSystem)

Hadoop FileSystem Validation Workstream (2013)

Hadoop has a pluggable FileSystem Architecture. 3rd party FileSystems can be enabled for Hadoop by developing a plugin that mediates between the Hadoop FileSystem Interface and the interface of the 3rd Party FileSystem. For those developing a Hadoop FileSystem plugin, there is no comprehensive test library to validate that their plugin creates a Hadoop FileSystem implementation that is Hadoop compatible.

What do we mean by comprehensive? We mean that there is a test for every single operation in the FS Interface that properly tests the expected behavior of the operation given the full variability of its parameters. To create a comprehensive test library, we plan to do the following:

* Focus on the Hadoop 2.0 FS Interface. If possible, create a work stream that would allow testing and validation of the FS 1.0 Interface also.

* Undertake an audit of the Hadoop FileSystem 1.0 Test Coverage - Link to Work In Progress

* Undertake an audit of the Hadoop FileSystem 2.0 Test Coverage - Link to Work In Progress

* Document the FileSystem 2.0 Specification (as a JavaDoc) as a JIRA Ticket

* Create a gap analysis contrasting the FileSystem 2.0 Specification and the audits of existing FileSystem 2.0 Test Coverage.

* Create tests to fill in the gaps

Once the comprehensive test library is complete, it can then be used by the provider of a 3rd Party FileSystem to verify compatibility with Hadoop by:


Next Meeting

June 25th 2013 - Face to Face meeting at Red Hat in Mountain View. The day before Hadoop Summit. Details/Sign up here - http://hadoop-fs.eventbrite.com/


Work thus far


June 10th 2013 9AM PST via Google Hangout

Attendees: Tim St. Clair, Matt Farrellee, Steve Watt, Jay Vyas, Steve Loughran, Sanjay Radia, Andrew Purtell, Joe Buck, Roman Shaposhnik, Nathan (?)

Agenda:

- Discussion of the goals of the work

- Steve Loughran to give an update on the Hadoop FS Tests he developed for SWIFT

- Discussion on where people would like to participate

Outcome:

- Validation of the current goals, plus the addition of:

The workstream definition at the top of this page has been updated to reflect the new additions to the initiative.


June 4th 2013

Created a diff report contrasting Hadoop FileSystem 1.0 and 2.0

Next step is to evaluate how comprehensive the unit test case coverage is for FileSystem 1.0 and 2.0. This is a work in progress Audit of the FileSystem 1.0 Test Library


May 23rd 2013 - A broader call for participation was made to the hadoop-core dev proposing:

* broader participation in defining the expected behavior of Hadoop FileSystem operations

* creating a comprehensive test suite verifying compliance with the expected behavior of a Hadoop FileSystem

* several google hangouts and a workshop to discuss the topics

The following parties responded that they were interested in participation: - mbhandarkar@gopivotal.com , shv.hadoop@gmail.com , stevel@hortonworks.com , erlv5241@gmail.com , shaposhnik@gmail.com , apurtell@apache.org , cdouglas@apache.org , jayhawk@cs.ucsc.edu , sanjay@hortonworks.com , dmitry.bimatov@isilon.com