NetCDF 4.6.2

Version 4.6.2 of the netCDF-C library is now available. Changes include (but are not limited to):

• Lazy attribute read — only read attributes when user requests one of them.
• Fast global attribute read — when global attributess are read, they are read much more quickly.
• Add nccopy command options for per-variable chunk sizing, and minimum chunk size.
• Fix nccopy handling of user specified chunk sizes.
• Avoid limit on number of times a netCDF4 attribute can be updated. Not a complete fix for the HDF5 "maximum creation order" problem, but should greatly reduce occurrences in many real-world cases.
• The use of NC_DISKLESS has been modified to make it cleaner. This adds a new flag called NC_PERSIST that takes over the now obsolete NC_MPIPOSIX.
• When using filters with HDF5 1.10.x or later, it is necessary to utilize the HDF5 replacements for malloc, realloc, and free in the filter code.
• Create a new version of _NCProperties provenance attribute. This version (version 2) supports arbitrary key-value pairs. It is the default when new files are created. Version 1 continues to be accepted.
• Allow user to set http read buffersize for DAP2 and DAP4 using the tag HTTP.READ.BUFFERSIZE in the .daprc file.
• Allow user to set http keepalive for DAP2 and DAP4 using the tag HTTP.KEEPALIVE in the .daprc file (see the OPeNDAP documentation for details).
• Support DAP4 remote tests using a new remote test server locatedon the Unidata JetStream project.
• Improved the performance of the nc_get/put_vars operations by using the equivalent slab capabilities of hdf5. Result is a significant speedup of these operations.
• Expanded the capabilities of NC_INMEMORY to support writing and accessing the final modified memory.
• Made CDF5 support enabled by default.
• Corrected a number of memory issues identified in ncgen.

Detailed information about the release is available in the Release Notes.

Complete information about using this release can be found in the NetCDF Documentation.

Source-code zip and tar.gz archives can be found on Unidata's NetCDF-C GitHub site.

Pre-built Windows binaries for use with Visual Studio) are available from this page.

Users of the netCDF FORTRAN and C++ Libraries Note

You can use the upgraded C library without upgrading your FORTRAN or C++ library.

Updated FORTRAN and C++libraries will be available shortly.