Hello,
My PC ran out of memory for running a large-scale model on it and I decided to move to a powerful linux server.
I installed AMPL on this server successfully, as after running a simplistic model on it I get optimal results back.
ampl: include t1.run;
However, when I want to run my large-scale model, I run into the following error that I do not know how to resolve.
ampl: include csephund.run;
I appreciate your help.
4er
November 15, 2023, 5:48pm
2
A message like “can’t open /tmp/at1228520.sol” means that the solver stopped running before it could write the file that contains the solution. This can happen because the solver program ran out of memory, but it could also be a crash for some other reason. The message does not provide any help in determining the cause, so it is necessary to run some tests to learn what is happening.
For an initial test, add the AMPL statement
option show_stats 1, times 1, gentimes 1;
to the beginning of csephund.run. Then execute include csephund.run again, and post all of the output that appears. This will provide useful information about the size and memory requirements of the problem you are attempting to solve.
Also, it will be helpful if you can upload csephund.run with your reply. You can do this by clicking the upload icon at the top of the Discourse editor window.
Here is the output:
ampl: include csephund.run;
incremental total
#phase seconds memory memory
#execute 0.029433 8144344 8144344
csephund.run:9(158) solve ...
#compile 0.000485 140984 8285328
##genmod times:
##seq seconds cum. sec. mem. inc. name
89 1e-06 1e-06 0 derstage
93 6e-06 7e-06 0 sstatus
107 3e-06 1e-05 0 G
108 4e-06 1.4e-05 0 K
109 3e-06 1.7e-05 0 II
110 6e-06 2.3e-05 0 JJ
111 3e-06 2.6e-05 0 I
112 5e-06 3.1e-05 0 J
113 2e-06 3.3e-05 0 RS
114 3e-06 3.6e-05 0 rrs
115 3e-06 3.9e-05 0 NRS
116 3e-06 4.2e-05 0 Ng
117 5e-06 4.7e-05 0 H
118 5e-06 5.2e-05 0 L
119 6e-06 5.8e-05 0 A
120 5e-06 6.3e-05 0 AS
121 3e-06 6.6e-05 0 ASp
122 5e-06 7.1e-05 0 ASpc
123 6e-06 7.7e-05 0 AT
124 2.9e-05 0.000106 0 Al
125 7e-05 0.000176 32800 AN
126 5e-06 0.000181 0 IA
127 4e-06 0.000185 0 Ap6
128 4e-06 0.000189 0 Ap6a
129 4e-06 0.000193 0 Ap6b
130 4e-06 0.000197 0 Ap6c
131 4e-06 0.000201 0 Ap6d
132 4e-06 0.000205 0 Ap6e
133 2e-06 0.000207 0 Ap6f
134 3e-06 0.00021 0 Ap6g
135 4e-06 0.000214 0 Ap378
136 3e-06 0.000217 0 Ap378a
137 3e-06 0.00022 0 Ap1428
138 5e-06 0.000225 0 Ap1428a
139 2e-06 0.000227 0 Ap1428b
140 4e-06 0.000231 0 Ap1428z
141 5e-06 0.000236 0 Ap1456
142 4e-06 0.00024 0 Ap1456a
143 5e-06 0.000245 0 Ap1456b
144 3e-06 0.000248 0 Ap1456c
145 4e-06 0.000252 0 Ap823
146 3e-06 0.000255 0 Ap823a
147 4e-06 0.000259 0 Ap823b
148 3e-06 0.000262 0 Ap823c
149 4e-06 0.000266 0 Ap823d
150 5e-06 0.000271 0 Ap823e
151 4e-06 0.000275 0 Ap104
152 5e-06 0.00028 0 Ap1076
153 2e-06 0.000282 0 Ap1076a
154 4e-06 0.000286 0 Ap1076b
155 3e-06 0.000289 0 Ap1076c
156 4e-06 0.000293 0 An6
157 3e-06 0.000296 0 An6a
158 4e-06 0.0003 0 An6b
159 5e-06 0.000305 0 An6c
160 4e-06 0.000309 0 An6d
161 4e-06 0.000313 0 An6e
162 5e-06 0.000318 0 An6f
163 2e-06 0.00032 0 An6g
164 3e-06 0.000323 0 An378
165 3e-06 0.000326 0 An378a
166 3e-06 0.000329 0 An1428
167 4e-06 0.000333 0 An1428a
168 5e-06 0.000338 0 An1428b
169 4e-06 0.000342 0 An1428z
170 3e-06 0.000345 0 An1456
171 4e-06 0.000349 0 An1456a
172 4e-06 0.000353 0 An1456b
173 5e-06 0.000358 0 An1456c
174 3e-06 0.000361 0 An823
175 4e-06 0.000365 0 An823a
176 4e-06 0.000369 0 An823b
177 5e-06 0.000374 0 An823c
178 4e-06 0.000378 0 An823d
179 3e-06 0.000381 0 An823e
180 4e-06 0.000385 0 An104
181 3e-06 0.000388 0 An1076
182 4e-06 0.000392 0 An1076a
183 3e-06 0.000395 0 An1076b
184 4e-06 0.000399 0 An1076c
185 3e-06 0.000402 0 ay
186 0.000141 0.000543 81976 b
187 5.2e-05 0.000595 0 c
188 5e-06 0.0006 0 T
189 5.1e-05 0.000651 0 alpha
190 5.2e-05 0.000703 0 beta
191 4e-06 0.000707 0 S
192 8e-06 0.000715 0 cc
193 4e-06 0.000719 0 ic01
194 3e-06 0.000722 0 icS1
195 4e-06 0.000726 0 pmin
196 3e-06 0.000729 0 pmax
197 4e-06 0.000733 0 emin
198 3e-06 0.000736 0 emax
199 4e-06 0.00074 0 e0
200 3e-06 0.000743 0 ens
201 0.00203 0.002773 0 pd
202 5.9e-05 0.002832 0 ppmin
203 5.2e-05 0.002884 0 ppmax
204 5.1e-05 0.002935 0 ur
205 5.3e-05 0.002988 0 dr
206 0.000208 0.003196 98376 plmax
207 7e-06 0.003203 0 sr
208 5.1e-05 0.003254 0 Toff
209 5.1e-05 0.003305 0 Ton
210 5e-06 0.00331 0 cap
211 3e-06 0.003313 0 capy
212 4e-06 0.003317 0 capa
213 4e-06 0.003321 0 v
214 4e-06 0.003325 0 o
215 7.7e-05 0.003402 0 x
216 0.000227 0.003629 0 branchdirct
217 0.004937 0.008566 3523552 pwu
218 9e-06 0.008575 0 voll
219 3.4e-05 0.008609 0 nu
220 4e-06 0.008613 0 M
221 0.005967 0.01458 4089344 P
223 0.001683 0.016263 1048592 Pw
225 0.001654 0.017917 1048592 Ir
227 0.001556 0.019473 1048592 Y
229 0.00155 0.021023 1048592 Z
231 0.001892 0.022915 918848 Ip
233 0.012785 0.0357 10245808 Pp
235 0.003214 0.038914 2097168 Ppp
237 50.5544 50.5933 23893098048 Q
239 0.001849 50.5952 0 Gr
241 2e-05 50.5952 0 E
243 0.008472 50.6037 4133352 Pl
245 0.000969 50.6046 0 theta
247 0.001183 50.6058 524296 Psh
249 0.003038 50.6089 3145760 nuv
251 0.002489 50.6113 2097168 xtilde
253 0.022866 50.6342 1568360 OF
255 0.000227 50.6344 0 n1
257 4.8e-05 50.6345 38920 n1a
259 9.3e-05 50.6346 13384 n1aa
261 2.1e-05 50.6346 0 n2a
263 1.4e-05 50.6346 0 n2a1
265 1.2e-05 50.6346 0 n2a2
267 1.3e-05 50.6346 0 n2a3
269 1.3e-05 50.6347 0 n2a4
271 1.2e-05 50.6347 0 n2a5
273 1.1e-05 50.6347 0 n2a6
275 3.3e-05 50.6347 38400 n2a7
277 3.3e-05 50.6347 33024 n2a8
279 1.3e-05 50.6348 0 n2a9
281 1e-05 50.6348 0 n2a10
283 1.3e-05 50.6348 0 n2a11
285 1.1e-05 50.6348 0 n2a12
287 9e-06 50.6348 0 n2a13
289 1.3e-05 50.6348 0 n2a14
291 1.3e-05 50.6348 0 n2a15
293 1.1e-05 50.6348 0 n2a16
295 1.1e-05 50.6348 0 n2a17
297 1.2e-05 50.6349 0 n2a18
299 1.2e-05 50.6349 0 n2a19
301 1.1e-05 50.6349 0 n2a20
303 1e-05 50.6349 0 n2a21
305 1.2e-05 50.6349 0 n2a22
307 1.1e-05 50.6349 0 n2a23
309 1e-05 50.6349 0 n2a24
311 1.7e-05 50.6349 0 n2a25
313 3.4e-05 50.635 38400 n2a26
315 1.2e-05 50.635 0 n2a27
317 9e-06 50.635 0 n2a28
319 0.001239 50.6362 581120 n2b
321 0.000982 50.6372 327880 n2c
323 0.003907 50.6411 1064016 n3a
325 0.001438 50.6426 345600 n3aa
327 3.8e-05 50.6426 38400 n4
329 6e-06 50.6426 0 n5p
331 0.000191 50.6428 55312 n5bp
333 0.000189 50.643 125976 n5bpp
335 0.000101 50.6431 38400 n5
337 5e-06 50.6431 0 n6
339 6.94436 57.5875 10119760 n8p
341 418.203 475.79 23911440 n8pp1
343 398.28 874.07 14022832 n8pp2
345 0.005815 874.076 1152000 n8ppm
347 3.7e-05 874.076 0 n8pa
349 0.021229 874.097 11746920 n8p2a
351 0.032113 874.129 3379200 n9
353 0.000492 874.13 108608 n10p
355 0.000398 874.13 169552 n11p
357 0.004445 874.135 1469976 n10
359 0.006271 874.141 2469392 n10a
361 0.01283 874.154 4414488 n11
363 0.01273 874.167 4376088 n12
365 0.011668 874.178 5410384 n13a
367 0.003778 874.182 958400 n13b
369 0.011973 874.194 5771224 n14a
371 0.003804 874.198 925600 n14b
373 0.011497 874.209 6574128 n15
375 0.005382 874.215 3876888 n16
377 0.019941 874.235 8405040 n17
379 0.014859 874.249 6832152 n17a
381 0.0113 874.261 6832152 n18
383 0.008816 874.27 6832152 n19
385 88.0643 962.334 26122131984 r1a
387 0.016717 962.351 3262704 r1b
389 0.010923 962.362 3492888 r1bb
391 0.011871 962.373 4491288 r1c
393 0.010536 962.384 3492888 r1cc
395 0.011014 962.395 4491288 r1d
397 0.006879 962.402 2724888 r2a
399 0.008279 962.41 2993688 r2b
401 0.008261 962.418 2993688 r2ab
403 0.008849 962.427 4145688 r2c
405 0.009161 962.436 4145688 r2ac
407 0.008829 962.445 4184088 r2d
#genmod 962.445 50224899256 50233184584
#merge 4.75065 4294967304 54528151888
#collect 33.3643 41202905792 95731057680
Presolve eliminates 192724771 constraints and 196576844 variables.
Adjusted problem:
500202 variables:
223474 binary variables
276728 linear variables
819580 constraints, all linear; 2101177 nonzeros
125154 equality constraints
694426 inequality constraints
1 linear objective; 57737 nonzeros.
#presolve 37.1216 24024228160 119755285840
#output 0.46025 0 119755285840
#Total 1038.17
Error at _cmdno 3 executing "solve" command
(file csephund.run, line 9, offset 158):
can't open /tmp/at3416919.sol
#execute 2.37971 24398640 119779684480
The run file is attached.csephund.run (354 Bytes)
4er
November 16, 2023, 4:52pm
4
In the table of “genmod times,” each row gives statistics for processing a particular component of your AMPL model: execution time (seconds), total execution time so far (com. sec.), and additional memory allocated for processing (mem. inc.). You can see that while most components require a reasonable amount of memory, there are two that require over 20 gigabytes: Q and r1a. To process these components and generate a problem for the solver, AMPL requires even more memory, so that the total memory allocation by the time of solving — shown in the last line of the listing — is over 100 gigabytes! (It’s 119,755,285,840 bytes, to be exact, as shown in the last line of the listing.)
The output from option show_stats 1 indicates that almost all of the variables and constraints that are generated are unnecessary, and can be eliminated by AMPL’s presolve phase, after which the problem to be solved actually has a reasonable size:
Presolve eliminates 192724771 constraints and 196576844 variables.
Adjusted problem:
500202 variables:
223474 binary variables
276728 linear variables
819580 constraints, all linear; 2101177 nonzeros
125154 equality constraints
694426 inequality constraints
1 linear objective; 57737 nonzeros.
So, you should look for an error in how Q and r1a are defined. The most likely cause is that the indexing sets in the definitions of Q and r1a are much larger than they need to be.