SAS Support Communities

Since you were successful with using SAS/OR 14.3 also, the issue may be with the computer hardware? I am using SAS/OR on a Unix server. I will check with our hardware folks why I can't get below 20% gap in reasonable time. What do you think? ... View more

Increasing the memory solved the "out of memory" problem. However, after 5 hours the solver could only get down to 20% gap while yours got down to 1% in 2.5 hours. Do you think the difference can be attributed to using 15.1 version?  That will have to wait until we upgrade to that version.      103454 102545 9 1314332 1075017 22.26% 15504 107197 106280 9 1314332 1075034 22.26% 16001 110686 109762 10 1305394 1075042 21.43% 16417 111106 110182 10 1305394 1075042 21.43% 16503 114870 113942 11 1296700 1075044 20.62% 16853 116177 115247 11 1296700 1075050 20.62% 17001 121863 120921 11 1296700 1075051 20.62% 17500 125398 124447 11 1296700 1075071 20.62% 17989 NOTE: Real time limit reached. NOTE: Objective of the best integer solution found = 1296700.2137.   NOTE: PROCEDURE OPTMODEL used (Total process time): real time 5:00:48.50 user cpu time 14:30:25.59 system cpu time 4:11.71 memory 13788369.93k OS Memory 13848088.00k Timestamp 04/16/2019 01:43:57 AM Step Count 30 Switch Count 28432 Page Faults 628 Page Reclaims 0 Page Swaps 0 Voluntary Context Switches 1867507 Involuntary Context Switches 1369205 Block Input Operations 0 Block Output Operations 100   ... View more

I ran out of memory after 2 hours with 24% relative gap.   NOTE: Problem generation will use 4 threads. NOTE: The problem has 162671 variables (0 free, 0 fixed). NOTE: The problem uses 2 implicit variables. NOTE: The problem has 162671 binary and 0 integer variables. NOTE: The problem has 2931 linear constraints (113 LE, 2818 EQ, 0 GE, 0 range). NOTE: The problem has 325229 linear constraint coefficients. NOTE: The problem has 0 nonlinear constraints (0 LE, 0 EQ, 0 GE, 0 range). NOTE: The remaining solution time after problem generation and solver initialization is 12590.68 seconds. NOTE: The MILP presolver value AUTOMATIC is applied. NOTE: The MILP presolver removed 2093 variables and 8 constraints. NOTE: The MILP presolver removed 4185 constraint coefficients. NOTE: The MILP presolver modified 16 constraint coefficients. NOTE: The presolved problem has 160578 variables, 2923 constraints, and 321044 constraint coefficients. NOTE: The MILP solver is called. NOTE: The parallel Branch and Cut algorithm is used. NOTE: The Branch and Cut algorithm is using up to 4 threads. Node Active Sols BestInteger BestBound Gap Time 0 1 3 1810300 2950.4854111 61256.0% 47 0 1 3 1810300 1050302 72.36% 48 0 1 3 1810300 1062232 70.42% 75 0 1 3 1810300 1066621 69.72% 96 0 1 3 1810300 1068548 69.42% 124 0 1 3 1810300 1069763 69.22% 162 0 1 3 1810300 1070563 69.10% 211 0 1 3 1810300 1071124 69.01% 276 0 1 3 1810300 1071673 68.92% 357 0 1 3 1810300 1071984 68.87% 452 0 1 3 1810300 1072216 68.84% 591 0 1 3 1810300 1072392 68.81% 691 0 1 3 1810300 1072530 68.79% 800 0 1 3 1810300 1072682 68.76% 905 0 1 3 1810300 1072829 68.74% 1014 NOTE: The MILP solver added 1988 cuts with 33934 cut coefficients at the root. 1 2 3 1810300 1072829 68.74% 1030 751 1 3 1810300 1073363 68.66% 1699 2842 2077 3 1810300 1073575 68.62% 2000 8112 7337 3 1810300 1073988 68.56% 2500 12671 11890 3 1810300 1074031 68.55% 3000 15756 14970 4 1497585 1074139 39.42% 3232 18259 17468 4 1497585 1074357 39.39% 3500 23711 22912 4 1497585 1074442 39.38% 4002 28663 27857 4 1497585 1074500 39.38% 4500 32773 31960 5 1451508 1074638 35.07% 4905 33029 32214 5 1451508 1074677 35.06% 5002 38138 37313 5 1451508 1074710 35.06% 5500 43450 42619 5 1451508 1074724 35.06% 6000 49459 48619 5 1451508 1074746 35.06% 6500 55063 54213 5 1451508 1074755 35.05% 7000 60147 59290 6 1421391 1074771 32.25% 7425 60674 59814 7 1328658 1074780 23.62% 7492 60971 60111 7 1328658 1074780 23.62% 7500 ERROR: Out of memory. NOTE: Objective of the best integer solution found = 1328657.5189.   NOTE: Total profiled time is 7851.03 seconds. NOTE: PROCEDURE OPTMODEL used (Total process time): real time 2:10:49.75 user cpu time 6:30:06.98 system cpu time 2:04.75 memory 8129798.53k OS Memory 8187904.00k Timestamp 04/14/2019 02:19:53 PM Step Count 22 Switch Count 12365 Page Faults 971 Page Reclaims 0 Page Swaps 0 Voluntary Context Switches 817916 Involuntary Context Switches 625004 Block Input Operations 1 Block Output Operations 102 ... View more

Glad to see your solution worked! I will try it and hopefully I will not get an "our of memory" as before. One thing, I am using SAS/OR 14.3 which is probably not as efficient as 15.1. Thanks again. ... View more

This is an operational requirement of assigning a customer to exactly one facility. ... View more

They were all exclude because they exceed the MaxStemDist. where PDStemTravelDistance <153 ; ... View more

where PDStemTravelDistance <153 ; ... View more

Even a zipped file (9.8MB) is still too large (limit 5Mb) to attach. ... View more

here are the 2 smaller files. ... View more

One file is too large to attach. ... View more

I will anonymize the data. In what format do you want me to send? ... View more

Sorry, but the data is confidential and I am not allowed to share it. ... View more

I ran out of memory using the model with 113 facilities and 2821 customer sites. Any other steps I can take? Thanks.   NOTE: Problem generation will use 4 threads. NOTE: The problem has 303155 variables (0 free, 0 fixed). NOTE: The problem uses 2 implicit variables. NOTE: The problem has 303155 binary and 0 integer variables. NOTE: The problem has 2934 linear constraints (113 LE, 2821 EQ, 0 GE, 0 range). NOTE: The problem has 606197 linear constraint coefficients. NOTE: The problem has 0 nonlinear constraints (0 LE, 0 EQ, 0 GE, 0 range). NOTE: The remaining solution time after problem generation and solver initialization is 7181.98 seconds. NOTE: The MILP presolver value AUTOMATIC is applied. NOTE: The MILP presolver removed 3686 variables and 0 constraints. NOTE: The MILP presolver removed 7372 constraint coefficients. NOTE: The MILP presolver modified 0 constraint coefficients. NOTE: The presolved problem has 299469 variables, 2934 constraints, and 598825 constraint coefficients. NOTE: The MILP solver is called. NOTE: The parallel Branch and Cut algorithm is used. NOTE: The Branch and Cut algorithm is using up to 4 threads. Node Active Sols BestInteger BestBound Gap Time 0 1 2 1812022 0 1812022 117 0 1 2 1812022 1052148 72.22% 119 0 1 2 1812022 1063880 70.32% 198 0 1 2 1812022 1068108 69.65% 225 0 1 2 1812022 1069878 69.37% 267 0 1 2 1812022 1070901 69.21% 333 0 1 2 1812022 1071674 69.08% 402 0 1 2 1812022 1072197 69.00% 480 0 1 2 1812022 1072624 68.93% 564 0 1 2 1812022 1072975 68.88% 662 0 1 2 1812022 1073282 68.83% 764 0 1 2 1812022 1073570 68.78% 875 0 1 2 1812022 1073762 68.75% 955 0 1 2 1812022 1073951 68.72% 1072 NOTE: The MILP solver added 1671 cuts with 13817 cut coefficients at the root. 1 2 2 1812022 1073951 68.72% 1091 752 1 2 1812022 1074456 68.65% 1823 4 The SAS System 09:43 Wednesday, April 3, 2019 956 202 2 1812022 1074498 68.64% 2000 4138 3366 2 1812022 1074498 68.64% 2500 6440 5652 2 1812022 1075663 68.46% 3000 8846 8047 2 1812022 1075806 68.43% 3502 12085 11280 2 1812022 1075809 68.43% 4000 15627 14815 2 1812022 1075857 68.43% 4500 18667 17843 3 1812012 1075857 68.42% 4873 18807 17982 3 1812012 1075857 68.42% 5006 22767 21926 3 1812012 1075858 68.42% 5500 ERROR: Out of memory. NOTE: Objective of the best integer solution found = 1812012.3024.   NOTE: PROCEDURE OPTMODEL used (Total process time): real time 1:37:58.90 user cpu time 4:38:00.91 system cpu time 2:01.14 memory 8095586.56k OS Memory 8186944.00k Timestamp 04/03/2019 11:23:25 AM Step Count 15 Switch Count 9261 Page Faults 785 Page Reclaims 0 Page Swaps 0 Voluntary Context Switches 605112 Involuntary Context Switches 341743 Block Input Operations 1 Block Output Operations 67   ... View more

Rob,   Thanks for your help. I am learning a lot from you. I first tried your suggestions on two medium-sized models and they significantly reduced the memory used. I will set it up next to test on a big model.   These are two great suggestions. Would these two be amenable to build into the pre-solver?   Thanks, Michael ... View more

Here is the PROC OPTMODEL code. For the problem size there are 113 facilities and 2821 customers. ... View more