HDF Newsletter 73

August 1, 2003

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CONTENTS


Release of HDF Java Products 1.3

The latest release of the HDF Java Products, version 1.3, is available for download from:
    http://hdf.ncsa.uiuc.edu/hdf-java-html/
This release was built and tested with HDF5-1.6.0.

For a list of the new features that are available with HDFView in this release, see the HDFView page at:

    http://hdf.ncsa.uiuc.edu/hdf-java-html/hdfview/

Data Corruption Bug in HDF5

There is a data corruption problem in HDF5-1.6.0 and previous releases which affects users who use the H5Pset_istore_k and H5Pget_istore_k functions to control B-trees for indexing chunked datasets. This feature has been disabled in the HDF5-1.4.5-post8 snapshot, and fixed in the HDF5-1.6.0-post* and development (HDF5-1.7*) snapshots. The fix required a slight change to the HDF5 format.

The latest HDF5 snapshots can be downloaded from:

    ftp://ftp.ncsa.uiuc.edu/HDF/pub/outgoing/hdf5/snapshots/

Detailed Information:

The HDF5 library provides API calls to control B-trees for indexing chunked datasets. The non-default 'K' value can be set up during file creation time and retrieved from the file creation property list by using the H5Pset_istore_k and H5Pget_istore_k functions.

The HDF5 library (1.6.0 release and any earlier releases) has the following problem:

When a non-default indexed storage B-tree internal 'K' value is set, the chunked datasets created in the file use the user's 'K' value. The data can be accessed correctly until the file is closed. After the file is closed, the non-default 'K' value is lost, since it is not stored in the file. This may cause data corruption for the chunked datasets with the non-default 'K' value.

In HDF5-1.4.5-post8, the H5Pset_istore_k function will not allow the default 'K' value to be changed, so no error is generated. In the HDF5-1.6.0-post* and HDF5-1.7* snapshots, the library properly stores and uses the user-defined 'K' value.

If your application uses non-default 'K' values for chunked datasets, we strongly recommend that you move to the next appropriate version of the library.

SGI IRIX64 and HP-UX 11.00 Support

We will be losing access to the SGI IRIX64 and HP-UX 11.00 machines that we use. If you have a machine running one of these platforms, and can give us an account on it, please let us know.


For questions regarding these or other HDF issues, contact:
   hdfhelp@ncsa.uiuc.edu