included best practices of using coll. metadata APIs (#4018)

9 files changed, 154 insertions, 8 deletions

diff --git a/HDF5Examples/C/H5PAR/ph5_dataset.c b/HDF5Examples/C/H5PAR/ph5_dataset.c
index 9b8e8a8..0c25fcc 100644
--- a/HDF5Examples/C/H5PAR/ph5_dataset.c
+++ b/HDF5Examples/C/H5PAR/ph5_dataset.c
@@ -54,6 +54,24 @@ main(int argc, char **argv)
     H5Pset_fapl_mpio(plist_id, comm, info);
 
     /*
+     * OPTIONAL: It is generally recommended to set collective
+     *           metadata reads on FAPL to perform metadata reads
+     *           collectively, which usually allows datasets
+     *           to perform better at scale, although it is not
+     *           strictly necessary.
+     */
+    H5Pset_all_coll_metadata_ops(plist_id, true);
+
+    /*
+     * OPTIONAL: It is generally recommended to set collective
+     *           metadata writes on FAPL to perform metadata writes
+     *           collectively, which usually allows datasets
+     *           to perform better at scale, although it is not
+     *           strictly necessary.
+     */
+    H5Pset_coll_metadata_write(plist_id, true);
+
+    /*
      * Create a new file collectively and release property list identifier.
      */
     file_id = H5Fcreate(H5FILE_NAME, H5F_ACC_TRUNC, H5P_DEFAULT, plist_id);
diff --git a/HDF5Examples/C/H5PAR/ph5_file_create.c b/HDF5Examples/C/H5PAR/ph5_file_create.c
index a3bd0a8..10938f2 100644
--- a/HDF5Examples/C/H5PAR/ph5_file_create.c
+++ b/HDF5Examples/C/H5PAR/ph5_file_create.c
@@ -37,6 +37,24 @@ main(int argc, char **argv)
     H5Pset_fapl_mpio(plist_id, comm, info);
 
     /*
+     * OPTIONAL: It is generally recommended to set collective
+     *           metadata reads on FAPL to perform metadata reads
+     *           collectively, which usually allows datasets
+     *           to perform better at scale, although it is not
+     *           strictly necessary.
+     */
+    H5Pset_all_coll_metadata_ops(plist_id, true);
+
+    /*
+     * OPTIONAL: It is generally recommended to set collective
+     *           metadata writes on FAPL to perform metadata writes
+     *           collectively, which usually allows datasets
+     *           to perform better at scale, although it is not
+     *           strictly necessary.
+     */
+    H5Pset_coll_metadata_write(plist_id, true);
+
+    /*
      * Create a new file collectively.
      */
     file_id = H5Fcreate(H5FILE_NAME, H5F_ACC_TRUNC, H5P_DEFAULT, plist_id);
diff --git a/HDF5Examples/C/H5PAR/ph5_filtered_writes.c b/HDF5Examples/C/H5PAR/ph5_filtered_writes.c
index 104704a..34ed2fb 100644
--- a/HDF5Examples/C/H5PAR/ph5_filtered_writes.c
+++ b/HDF5Examples/C/H5PAR/ph5_filtered_writes.c
@@ -377,14 +377,24 @@ main(int argc, char **argv)
     H5Pset_fapl_mpio(fapl_id, comm, info);
 
     /*
-     * OPTIONAL: Set collective metadata reads on FAPL to allow
-     *           parallel writes to filtered datasets to perform
-     *           better at scale. While not strictly necessary,
-     *           this is generally recommended.
+     * OPTIONAL: It is generally recommended to set collective
+     *           metadata reads on FAPL to perform metadata reads
+     *           collectively, which usually allows filtered datasets
+     *           to perform better at scale, although it is not
+     *           strictly necessary.
      */
     H5Pset_all_coll_metadata_ops(fapl_id, true);
 
     /*
+     * OPTIONAL: It is generally recommended to set collective
+     *           metadata writes on FAPL to perform metadata writes
+     *           collectively, which usually allows filtered datasets
+     *           to perform better at scale, although it is not
+     *           strictly necessary.
+     */
+    H5Pset_coll_metadata_write(fapl_id, true);
+
+    /*
      * OPTIONAL: Set the latest file format version for HDF5 in
      *           order to gain access to different dataset chunk
      *           index types and better data encoding methods.
diff --git a/HDF5Examples/C/H5PAR/ph5_filtered_writes_no_sel.c b/HDF5Examples/C/H5PAR/ph5_filtered_writes_no_sel.c
index a4d9e16..d4f171f 100644
--- a/HDF5Examples/C/H5PAR/ph5_filtered_writes_no_sel.c
+++ b/HDF5Examples/C/H5PAR/ph5_filtered_writes_no_sel.c
@@ -271,14 +271,24 @@ main(int argc, char **argv)
     H5Pset_fapl_mpio(fapl_id, comm, info);
 
     /*
-     * OPTIONAL: Set collective metadata reads on FAPL to allow
-     *           parallel writes to filtered datasets to perform
-     *           better at scale. While not strictly necessary,
-     *           this is generally recommended.
+     * OPTIONAL: It is generally recommended to set collective
+     *           metadata reads on FAPL to perform metadata reads
+     *           collectively, which usually allows filtered datasets
+     *           to perform better at scale, although it is not
+     *           strictly necessary.
      */
     H5Pset_all_coll_metadata_ops(fapl_id, true);
 
     /*
+     * OPTIONAL: It is generally recommended to set collective
+     *           metadata writes on FAPL to perform metadata writes
+     *           collectively, which usually allows filtered datasets
+     *           to perform better at scale, although it is not
+     *           strictly necessary.
+     */
+    H5Pset_coll_metadata_write(fapl_id, true);
+
+    /*
      * OPTIONAL: Set the latest file format version for HDF5 in
      *           order to gain access to different dataset chunk
      *           index types and better data encoding methods.
diff --git a/HDF5Examples/C/H5PAR/ph5_hyperslab_by_chunk.c b/HDF5Examples/C/H5PAR/ph5_hyperslab_by_chunk.c
index a255b96..e00a0ef 100644
--- a/HDF5Examples/C/H5PAR/ph5_hyperslab_by_chunk.c
+++ b/HDF5Examples/C/H5PAR/ph5_hyperslab_by_chunk.c
@@ -65,6 +65,24 @@ main(int argc, char **argv)
     H5Pset_fapl_mpio(plist_id, comm, info);
 
     /*
+     * OPTIONAL: It is generally recommended to set collective
+     *           metadata reads on FAPL to perform metadata reads
+     *           collectively, which usually allows datasets
+     *           to perform better at scale, although it is not
+     *           strictly necessary.
+     */
+    H5Pset_all_coll_metadata_ops(plist_id, true);
+
+    /*
+     * OPTIONAL: It is generally recommended to set collective
+     *           metadata writes on FAPL to perform metadata writes
+     *           collectively, which usually allows datasets
+     *           to perform better at scale, although it is not
+     *           strictly necessary.
+     */
+    H5Pset_coll_metadata_write(plist_id, true);
+
+    /*
      * Create a new file collectively and release property list identifier.
      */
     file_id = H5Fcreate(H5FILE_NAME, H5F_ACC_TRUNC, H5P_DEFAULT, plist_id);
diff --git a/HDF5Examples/C/H5PAR/ph5_hyperslab_by_col.c b/HDF5Examples/C/H5PAR/ph5_hyperslab_by_col.c
index b397fcf..49e5ce3 100644
--- a/HDF5Examples/C/H5PAR/ph5_hyperslab_by_col.c
+++ b/HDF5Examples/C/H5PAR/ph5_hyperslab_by_col.c
@@ -60,6 +60,24 @@ main(int argc, char **argv)
     H5Pset_fapl_mpio(plist_id, comm, info);
 
     /*
+     * OPTIONAL: It is generally recommended to set collective
+     *           metadata reads on FAPL to perform metadata reads
+     *           collectively, which usually allows datasets
+     *           to perform better at scale, although it is not
+     *           strictly necessary.
+     */
+    H5Pset_all_coll_metadata_ops(plist_id, true);
+
+    /*
+     * OPTIONAL: It is generally recommended to set collective
+     *           metadata writes on FAPL to perform metadata writes
+     *           collectively, which usually allows datasets
+     *           to perform better at scale, although it is not
+     *           strictly necessary.
+     */
+    H5Pset_coll_metadata_write(plist_id, true);
+
+    /*
      * Create a new file collectively and release property list identifier.
      */
     file_id = H5Fcreate(H5FILE_NAME, H5F_ACC_TRUNC, H5P_DEFAULT, plist_id);
diff --git a/HDF5Examples/C/H5PAR/ph5_hyperslab_by_pattern.c b/HDF5Examples/C/H5PAR/ph5_hyperslab_by_pattern.c
index 77f3bef..bec3a2f 100644
--- a/HDF5Examples/C/H5PAR/ph5_hyperslab_by_pattern.c
+++ b/HDF5Examples/C/H5PAR/ph5_hyperslab_by_pattern.c
@@ -65,6 +65,24 @@ main(int argc, char **argv)
     H5Pset_fapl_mpio(plist_id, comm, info);
 
     /*
+     * OPTIONAL: It is generally recommended to set collective
+     *           metadata reads on FAPL to perform metadata reads
+     *           collectively, which usually allows datasets
+     *           to perform better at scale, although it is not
+     *           strictly necessary.
+     */
+    H5Pset_all_coll_metadata_ops(plist_id, true);
+
+    /*
+     * OPTIONAL: It is generally recommended to set collective
+     *           metadata writes on FAPL to perform metadata writes
+     *           collectively, which usually allows datasets
+     *           to perform better at scale, although it is not
+     *           strictly necessary.
+     */
+    H5Pset_coll_metadata_write(plist_id, true);
+
+    /*
      * Create a new file collectively and release property list identifier.
      */
     file_id = H5Fcreate(H5FILE_NAME, H5F_ACC_TRUNC, H5P_DEFAULT, plist_id);
diff --git a/HDF5Examples/C/H5PAR/ph5_hyperslab_by_row.c b/HDF5Examples/C/H5PAR/ph5_hyperslab_by_row.c
index 5035786..1c08a32 100644
--- a/HDF5Examples/C/H5PAR/ph5_hyperslab_by_row.c
+++ b/HDF5Examples/C/H5PAR/ph5_hyperslab_by_row.c
@@ -49,6 +49,24 @@ main(int argc, char **argv)
     H5Pset_fapl_mpio(plist_id, comm, info);
 
     /*
+     * OPTIONAL: It is generally recommended to set collective
+     *           metadata reads on FAPL to perform metadata reads
+     *           collectively, which usually allows datasets
+     *           to perform better at scale, although it is not
+     *           strictly necessary.
+     */
+    H5Pset_all_coll_metadata_ops(plist_id, true);
+
+    /*
+     * OPTIONAL: It is generally recommended to set collective
+     *           metadata writes on FAPL to perform metadata writes
+     *           collectively, which usually allows datasets
+     *           to perform better at scale, although it is not
+     *           strictly necessary.
+     */
+    H5Pset_coll_metadata_write(plist_id, true);
+
+    /*
      * Create a new file collectively and release property list identifier.
      */
     file_id = H5Fcreate(H5FILE_NAME, H5F_ACC_TRUNC, H5P_DEFAULT, plist_id);
diff --git a/HDF5Examples/C/H5PAR/ph5example.c b/HDF5Examples/C/H5PAR/ph5example.c
index 5ec2cdc..37d5d68 100644
--- a/HDF5Examples/C/H5PAR/ph5example.c
+++ b/HDF5Examples/C/H5PAR/ph5example.c
@@ -269,6 +269,24 @@ phdf5writeInd(char *filename)
     assert(ret != FAIL);
     MESG("H5Pset_fapl_mpio succeed");
 
+    /*
+     * OPTIONAL: It is generally recommended to set collective
+     *           metadata reads on FAPL to perform metadata reads
+     *           collectively, which usually allows datasets
+     *           to perform better at scale, although it is not
+     *           strictly necessary.
+     */
+    H5Pset_all_coll_metadata_ops(acc_tpl1, true);
+
+    /*
+     * OPTIONAL: It is generally recommended to set collective
+     *           metadata writes on FAPL to perform metadata writes
+     *           collectively, which usually allows datasets
+     *           to perform better at scale, although it is not
+     *           strictly necessary.
+     */
+    H5Pset_coll_metadata_write(acc_tpl1, true);
+
     /* create the file collectively */
     fid1 = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, acc_tpl1);
     assert(fid1 != FAIL);