HDF5 Software Process

11/7/2007HDF and HDF-EOS Workshop XI, Landover,

MD 1

HDF5 Software Process

MuQun Yang, Quincey Koziol, Elena Pourmal

The HDF Group

Purposes

• Demonstrate how we maintain HDF5- Libraries and tools built on top of HDF5• HDF-EOS5, NetCDF4 and Pytables etc

• Hear your feedback


MD 2

Three pillars for robust software

• Correctness• Performance• Coding standard


MD 3

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


MD 4

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


MD 5

HDF5 software challenges - Others

• 34 configuration features --enable-cxx, --enable-fortran etc.

• THE TESTING CHALLENGEmachines x operating systems x compilers x languagesx 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


MD 6

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


MD 7

Daily automatic test procedure


MD 8

Start the automatic job 1. Configuring2. Compiling library and tools3. Running tests for library and tools4. Installing the library5. Testing examples

Sending out the results to hdf5 library mailinglists

1. Platform watcher diagnoses the failure2. Inform the corresponding developer if the failure is real

The developer fixes the problem

An example for daily test

Date: Tue, 6 Nov 2007 08:00:15 -0600 [08:00:15 AM CST]

From: HDF Tester [email protected]: [email protected]: kagiso

HDF5_Daily_Tests_1106Tue_FAILED!!!


MD 9

Date: Tue, 6 Nov 2007 09:23:49 -0600 [09:23:49 AM CST]

From:

Quincey Koziol <[email protected]>

To: [email protected]:

Re: kagiso HDF5_Daily_Tests_1106Tue_FAILED!!!


MD 10

Other helpers

• Committest script-automatically test a few platforms before checking in source code

• Save developers’ time


MD 11

Performance

• High IO performance is always a goal for THG

• Detect bad performance in time• Performance framework


MD 12

Performance framework

• Easy to Use for Various Benchmarks

• Multiple Platforms and Versions

• Long Term Regression Tests

• Help Debugging


MD 13


MD 14

Background

• Backend: Cron job / DB Storage

• Core: Performance C/C++ Library

• Frontend: PHP / jpgraph


MD 15

Solution

Easy to Use

A User’s Benchmark

Performance Library

Database

Web Server

cron

www

HDF5 1.6 HDF5 1.8

PHP

Graph/Text


MD 16

| 178820 | 2007-08-17 21:51:14 | 10000 groups | creating 10000 empty groups | 1.8.0 | hdfdap | 0.670198 | 4384 |

for(i=0;i<1000 ;i++) { H5Gcreate(fileid,group_name,(size_t)0)); // Add groups}

H5Perf_endTimer(&time);

H5Perf_startTimer(&time);

H5Perf_addInstance(db_host, date, time);

Example Usage

00 21 * * * /home/local/hyoklee/src/chicago/test-perf-hdfdap-3.sh

Timestamp Instance Name Version Platform Time

Demo

http://hdfdap.hdfgroup.uiuc.edu/h5perf/index.html

11/7/2007 17HDF and HDF-EOS Workshop XI, Landover,

MD

Other Performance work

• Performance studiescompression, chunking and parallel IOhttp://www.hdfgroup.uiuc.edu/papers/papers/


MD 18

Coding standard

• Not much except seminars on HDF4/HDF5 coding standards – We definitely need to improve in this area


MD 19

Other work we have done to improve software process


MD 20

User involvements

• Public mailing [email protected]@[email protected]@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


MD 21

Trainings for developers

• Internally Book reading: Programming Pearls

• Attending Dr. Dobb’s software conference


MD 22

Near-term plan

• Enhance daily correctness testsAPI compatibility tests: doneAPI Version tests: in the processJava wrapper tests: doneOpen source packages that use HDF

oEOS2 with HDF4oEOS5 with HDF5oNetCDF4 with HDF5

• Weekly “stable” code snapshots


MD 23

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


MD 24


MD 2525

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.

HDF5 Software Process

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