Updated RELEASE.txt with updates regarding HDFFV-10540

1 files changed, 21 insertions, 1 deletions

diff --git a/release_docs/RELEASE.txt b/release_docs/RELEASE.txt
index b8b14ab..8717c7e 100644
--- a/release_docs/RELEASE.txt
+++ b/release_docs/RELEASE.txt
@@ -243,13 +243,23 @@ New Features
 
     - Changed the default behavior in parallel when reading the same dataset in its entirely
       (i.e. H5S_ALL dataset selection) which is being read by all the processes collectively.
-      The dataset mush be contiguous, less than 2GB, and of an atomic datatype.
+      The dataset must be contiguous, less than 2GB, and of an atomic datatype.
       The new behavior is the HDF5 library will use an MPI_Bcast to pass the data read from
       the disk by the root process to the remain processes in the MPI communicator associated
       with the HDF5 file.
 
       (MSB - 2019/01/02, HDFFV-10652)
 
+    - Supporting 2GB IO with MPI 2 functionality was implemented and tested.
+      The proposed support recognizes IO operations > 2GB and if the datatype
+      is not a derived type, breaks the IO into chunks which can be input or
+      output with the existing MPI 2 limitations, e.g. size reporting and function
+      API size/count arguments are restricted to be 32 bit integers.
+      Derived types in which the datatype size is > 2GB still result in
+      IO failures. As a result, this BUG remains unresolved.
+
+      (RAW - 2019/02/14, HDFFV-10540)
+
     Fortran Library:
     ----------------
     - Added wrappers for dataset object header minimization calls.
@@ -1022,6 +1032,16 @@ Known Problems
     CPP ptable test fails on VS2017 with Intel compiler, JIRA issue: HDFFV-10628.
     This test will pass with VS2015 with Intel compiler.
 
+    Older MPI-2 libraries such as OpenMPI 2.0.1 and MPICH 2.1.5 were tested
+    while attempting to resolve the Jira issue: HDFFV-10540.
+    The known problems of reading or writing > 2GBs when using MPI-2 was
+    partially resolved with the MPICH library but OpenMPI testing produces
+    too many errors.  Within a single parallel test (testphdf5), the following
+    subtests report data verfication errors (cdsetr, eidsetr) before eventually
+    aborting.  More recent versions (v3.1.3 or newer) of OpenMPI appear to have
+    resolved most of the known testing problems even though occasional test
+    hangs have been observed.
+
     Known problems in previous releases can be found in the HISTORY*.txt files
     in the HDF5 source. Please report any new problems found to
     help@hdfgroup.org.