Sponsor:

Advanced Scientific Computing Research (ASCR) under the U.S. Department of Energy Office of Science (Office of Science)

Project Team Members:

Northwestern University

• Alok Choudhary
• Wei-keng Liao
• Kui Gao
• Saba Sehrish
• Chen Jin
• William Hendrix
• Seung Woo Son

The HDF Group

• Quincey Koziol
• Gerd Herber

Argonne National Laboratory

• Rob Ross
• Rob Latham
• Tim Tautges
• Venkat Vishwanath

North Carolina State University

• Nagiza Samatova
• Sriram Lakshminarasimhan

---

---

Damsel API Usecase - parallel write connectivity

In this use case, each rank owns a set of 5 vertices and then rank 0 uses 10 vertices i.e. 5 of its own and 5 from rank1 to create 5 edges. The five vertices on each rank are tagged with some pressure values and the five edges on rank 0 are tagged with some temperature values. The following steps are used in damsel.

• Data to be written by rank 0 Pressure = {0, 11, 22, 33, 44} and temperature = {40, 50, 60, 70, 80}, and rank 1 pressure = {1, 12, 23, 34, 45}
• Create a container of 5 damsel handles using DMSLcontainer_create_vector Or DMSLcontainer_create_sequence on rank 0 and rank 1
• Create a container of 5 damsel handles on rank 0, these will be local handles on rank 0 and will be mapped to the handles on rank 1
• Use container in step 2 to define 5 vertex entities on rank 0 and rank 1- DMSLentity_define
• Use damsel handles from the containers in step 2 and 3 on rank 0 to define edge entities
• Define a tag named Pressure with some values on each rank and map the tag data to the handles in the container created in Step 1 - DMSLtag_define, DMSL_model_map_tag
• Define a tag named Temperature on rank 0 and map the tag data to the edge handles following the same steps as above
• Rank 1 sends the five vertex handles to rank 0, and rank 0 maps its local handles from step 3 to the remote handles it received - DMSL_map_global_handles
• Create a file and invent file side handles
• Execute asyn write

The result in the h5 file after both rank 0 and rank 1 execute the above steps looks like

HDF5 "/orangefs/ssehrish/test-edges-parallel.h5" { GROUP "/" {

DATASET "Pressure-2000013a8" {

DATATYPE H5T_STD_I16LE DATASPACE SIMPLE { ( 5 ) / ( 5 ) } DATA { (0): 0, 11, 22, 33, 44 }

} DATASET "Pressure-300001395" {

DATATYPE H5T_STD_I16LE DATASPACE SIMPLE { ( 5 ) / ( 5 ) } DATA { (0): 1, 12, 23, 34, 45 }

} DATASET "Temperature-20000139a" {

DATATYPE H5T_STD_I16LE DATASPACE SIMPLE { ( 5 ) / ( 5 ) } DATA { (0): 40, 50, 60, 70, 80 }

}

.....

The code for this test case is in test-nconnectivitywrite.c

EECS Home | McCormick Home | Northwestern Home | Calendar: Plan-It Purple © 2011 Robert R. McCormick School of Engineering and Applied Science, Northwestern University "Tech": 2145 Sheridan Rd, Tech L359, Evanston IL 60208-3118  |  Phone: (847) 491-5410  |  Fax: (847) 491-4455 "Ford": 2133 Sheridan Rd, Ford Building, Rm 3-320, Evanston, IL 60208  |  Fax: (847) 491-5258 Email Director Last Updated: $LastChangedDate: 2016-11-06 13:53:06 -0600 (Sun, 06 Nov 2016) $