Dr. Saleem Al-Ashhab from Al Bait University in Jordan submitted over 410000 jobs to the GRID network and used around 3 TB of Disk Space.
Dr. Saleem Al-Ashhab said: “As a GRID user since 2012. I submitted so far over 41000 jobs to GRID. A job has five values as input. The first three values (a, b, e) represent the center of a magic square. We have 3429 possible centers. The other two values (integers from 0 to 36) are determined by the user. The input runs a C code, which produces two output files: one containing the number of squares and one containing the squares. For example, the table for center a=1, b= 35 and e=8:
|
t0 |
t1 |
number |
|
0 |
4 |
18731726 |
|
4 |
6 |
11497986 |
|
6 |
8 |
2888428 |
|
8 |
12 |
21562055 |
|
12 |
15 |
14509637 |
|
15 |
18 |
14827209 |
|
18 |
22 |
20480154 |
|
22 |
27 |
24735497 |
|
27 |
36 |
25194961 |
The will be number summarized in a new table according to the center. For example, the beginning of the table a=1, b= 35:
|
e |
Number |
|
2 |
80012582 |
|
4 |
172963666 |
|
5 |
161824291 |
|
6 |
147899103 |
|
7 |
125385153 |
|
8 |
154427653 |
I splitted the work of counting the squares into 4 stages according to the center: symmetric centers (153 ones), semi symmetric centers (total 306 ones), positive centers (228 ones) and the rest. The first two stages were finished and described in two published papers. I used GRID in the third stage, which is now complete (paper in preparation). I finished in the fourth stage all centers such that a = 1, 2, 13, 14, 15, 16, 17. They represent about 30% of the work. Regarding the other values I finished partially the jobs (in total about 60%).
The GRID is a powerful tool. It enables the user to split the work in parallel running processes. The run time for a single process is the same as a usual pc. This enables me to solve the problem in several months instead of years. But, the major problem is “vanishing of submitted jobs”. Sometimes they just disappear. The system does not execute all submitted jobs, which means that some jobs are resubmitted many times. Since there are no direct relations between the jobs, this problem is not an obstacle. Besides, the administrator R. Bruno is offering assistance. The system recently allows me rarely to download the output file containing the squares directly. It is a file of average 400MB. The system stores these files. The download process is not each time successful. At least in my case the other file (average size 2KB) contains the summary. Hence, the data transfer is not an essential obstacle.”
