HDF5 Software Process

1. HDF5 Software Process MuQun Yang, Quincey Koziol, Elena Pourmal The HDF Group HDF and HDF-EOS Workshop XI, Landover, MD

2. Purposes • Demonstrate how we maintain HDF5 - Libraries and tools built on top of HDF5 • HDF-EOS5, NetCDF4 and Pytables etc • Hear your feedback HDF and HDF-EOS Workshop XI, Landover, MD

3. Three pillars for robust software • Correctness • Performance • Coding standard HDF and HDF-EOS Workshop XI, Landover, MD

4. HDF5 software challenges - Portability • Portability: IBM,SGI,windows, linux, Solaris, OSF1, cygwin, Cray,FreeBSD, Mac-OS • Parallel IO: depends on MPI-IO, parallel File System and hardware - MPI-IO: IBM AIX, MPICH, SGI Altix - Parallel File System: GPFS, Lustre HDF and HDF-EOS Workshop XI, Landover, MD

5. HDF5 software challenges - Features • Programming languages - C, Fortran, C++ • External libraries: szlib encoder and decoder, zlib • Comprehensive internal library test suite - time-consuming tests: fractral heap HDF and HDF-EOS Workshop XI, Landover, MD

6. HDF5 software challenges - Others • 34 configuration features --enable-cxx, --enable-fortran etc. • THE TESTING CHALLENGE machines x operating systems x compilers x languages x Szip (encoder + no encoder) x (serial + parallel) = a very large number • Coordination among developers - 3-4 core library developers 5-6 developers for tools and others - subversion not enough HDF and HDF-EOS Workshop XI, Landover, MD

7. Solutions • HDF5 Daily Test on main-stream UNIX platforms • Rob Matzke started around 1997 • Albert Cheng took over • More platforms, testing with more features • Different version of HDF5 1.6, 1.8 • Other product: HDF4 • Other platforms: Windows HDF and HDF-EOS Workshop XI, Landover, MD

8. Daily automatic test procedure Start the automatic job 1. Configuring 2. Compiling library and tools 3. Running tests for library and tools 4. Installing the library 5. Testing examples Sending out the results to hdf5 library mailing lists 1. Platform watcher diagnoses the failure 2. Inform the corresponding developer if the failure is real The developer fixes the problem HDF and HDF-EOS Workshop XI, Landover, MD

9. An example for daily test Date:  Tue, 6 Nov 2007 08:00:15 -0600 [08:00:15 AM CST] From:  HDF Tester hdftest@hdfgroup.org To:hdf5lib@hdfgroup.org Subject:  kagiso HDF5_Daily_Tests_1106Tue_FAILED!!! HDF and HDF-EOS Workshop XI, Landover, MD

10. HDF and HDF-EOS Workshop XI, Landover, MD

11. Other helpers • Committest script -automatically test a few platforms before checking in source code • Save developers’ time HDF and HDF-EOS Workshop XI, Landover, MD

12. Performance • High IO performance is always a goal for THG • Detect bad performance in time • Performance framework HDF and HDF-EOS Workshop XI, Landover, MD

13. Performance framework • Easy to Use for Various Benchmarks • Multiple Platforms and Versions • Long Term Regression Tests • Help Debugging HDF and HDF-EOS Workshop XI, Landover, MD

14. Background • Backend: Cron job / DB Storage • Core: Performance C/C++ Library • Frontend: PHP / jpgraph HDF and HDF-EOS Workshop XI, Landover, MD

15. Solution Easy to Use HDF5 1.6 HDF5 1.8 Database cron A User’s Benchmark Performance Library PHP Web Server www Graph/Text HDF and HDF-EOS Workshop XI, Landover, MD

16. Example Usage H5Perf_startTimer(&time); for(i=0;i<1000 ;i++) { H5Gcreate(fileid,group_name,(size_t)0)); // Add groups } H5Perf_endTimer(&time); H5Perf_addInstance(db_host, date, time); 00 21 * * * /home/local/hyoklee/src/chicago/test-perf-hdfdap-3.sh | 178820 | 2007-08-17 21:51:14 | 10000 groups | creating 10000 empty groups | 1.8.0 | hdfdap | 0.670198 | 4384 | Timestamp Instance Name Version Platform Time HDF and HDF-EOS Workshop XI, Landover, MD

17. Demo http://hdfdap.hdfgroup.uiuc.edu/h5perf/index.html HDF and HDF-EOS Workshop XI, Landover, MD

18. Other Performance work • Performance studies compression, chunking and parallel IO http://www.hdfgroup.uiuc.edu/papers/papers/ HDF and HDF-EOS Workshop XI, Landover, MD

19. Coding standard • Not much except seminars on HDF4/HDF5 coding standards – We definitely need to improve in this area HDF and HDF-EOS Workshop XI, Landover, MD

20. Other work we have done to improve software process HDF and HDF-EOS Workshop XI, Landover, MD

21. User involvements • Public mailing lists hdf-forum@hdfgroup.org hdfnews@hdfgroup.org hdf4dev@hdfgroup.org hdf5dev@hdfgroup.org • Public RFCs • Solicit comments for new HDF5 features etc. http://www.hdfgroup.uiuc.edu/RFC/HDF5/ • Ask special groups to give us feedback http://www.hdfgroup.uiuc.edu/RFC/HDF5/H5CHK/ • Subversion repo HDF and HDF-EOS Workshop XI, Landover, MD

22. Trainings for developers • Internally Book reading: Programming Pearls • Attending Dr. Dobb’s software conference HDF and HDF-EOS Workshop XI, Landover, MD

23. Near-term plan • Enhance daily correctness tests • API compatibility tests: done • API Version tests: in the process • Java wrapper tests: done • Open source packages that use HDF • EOS2 with HDF4 • EOS5 with HDF5 • NetCDF4 with HDF5 • Weekly “stable” code snapshots HDF and HDF-EOS Workshop XI, Landover, MD

24. Long-term Plan • Coding standard: code review • Standards : - In the process of applying for ISO/ANSI standard for HDF5 • 500 random API tests to avoid ungraceful crash • Collect existing HDF5 files such as EOS2, EOS5 files - Running all HDF4/HDF5 tools on these files periodically • Daily correlation regression tests on external machines HDF and HDF-EOS Workshop XI, Landover, MD

25. Acknowledgement • This work was supported basing upon the Cooperative Agreement with the National Aeronautics and Space Administration (NASA) under NASA grant NNX06AC83A.  Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of NASA.  HDF and HDF-EOS Workshop XI, Landover, MD 25