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Google's Operations Research tools:
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parameter num_search_workers doesn't work when great then 8 #1420

Closed mojinfu closed 5 years ago

mojinfu commented 5 years ago

my project is running on an 48-logic-core computer

when I set parameter num_search_workers = 6 , it works perfectly. ( takes 600% cpu ) ''' pyhton self.solver.parameters.search_branching = self.rule.search_branching self.solver.parameters.max_time_in_seconds = 10000 self.solver.parameters.log_search_progress = True self.solver.parameters.num_search_workers = 6 '''

but when I set parameter num_search_workers = 7 or > 7 , it still works with 600% cpu

Are there any additional parameters that need to be set ?

lperron commented 5 years ago

I currently does not use more that threads until it has found a first feasible solution for the LNS to kick in. Laurent Perron | Operations Research | lperron@google.com | (33) 1 42 68 53 00

Le ven. 12 juil. 2019 à 03:55, mojinfu notifications@github.com a écrit :

my project is running on an 48-logic-core computer

when I set parameter num_search_workers = 6 , it works perfectly. ( takes 600% cpu ) ''' pyhton self.solver.parameters.search_branching = self.rule.search_branching self.solver.parameters.max_time_in_seconds = 10000 self.solver.parameters.log_search_progress = True self.solver.parameters.num_search_workers = 6 '''

but when I set parameter num_search_workers = 7 or > 7 , it still works with 600% cpu

Are there any additional parameters that need to be set ?

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lperron commented 5 years ago

Please note that this is completely changing for the next version. Laurent Perron | Operations Research | lperron@google.com | (33) 1 42 68 53 00

Le ven. 12 juil. 2019 à 05:52, Laurent Perron lperron@google.com a écrit :

I currently does not use more that threads until it has found a first feasible solution for the LNS to kick in. Laurent Perron | Operations Research | lperron@google.com | (33) 1 42 68 53 00

Le ven. 12 juil. 2019 à 03:55, mojinfu notifications@github.com a écrit :

my project is running on an 48-logic-core computer

when I set parameter num_search_workers = 6 , it works perfectly. ( takes 600% cpu ) ''' pyhton self.solver.parameters.search_branching = self.rule.search_branching self.solver.parameters.max_time_in_seconds = 10000 self.solver.parameters.log_search_progress = True self.solver.parameters.num_search_workers = 6 '''

but when I set parameter num_search_workers = 7 or > 7 , it still works with 600% cpu

Are there any additional parameters that need to be set ?

— You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub https://github.com/google/or-tools/issues/1420?email_source=notifications&email_token=ACUPL3NB5CTXRAOS35KSPPLP7BPIRA5CNFSM4ICHGNY2YY3PNVWWK3TUL52HS4DFUVEXG43VMWVGG33NNVSW45C7NFSM4G63HEEA, or mute the thread https://github.com/notifications/unsubscribe-auth/ACUPL3NGKM3NTSDRO64E6S3P7BPIRANCNFSM4ICHGNYQ .

mojinfu commented 5 years ago

i understand the reason is that “This tool contains only six algorithms for finding solutions，and every algorithm to another is can run on different thread .
but single algorithm can not run on two thread “ is that correct?

lperron commented 5 years ago

Yes and yes. Laurent Perron | Operations Research | lperron@google.com | (33) 1 42 68 53 00

Le ven. 12 juil. 2019 à 09:59, mojinfu notifications@github.com a écrit :

i understand the reason is that “This tool contains only six algorithms for finding solutions，and every algorithm to another is can run on different thread . but single algorithm can not run on two thread “ is that correct?

— You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHub https://github.com/google/or-tools/issues/1420?email_source=notifications&email_token=ACUPL3MHMC54TF55ANC445TP7CZ6DA5CNFSM4ICHGNY2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGODZ2J32A#issuecomment-510959080, or mute the thread https://github.com/notifications/unsubscribe-auth/ACUPL3L26N4UKEOLCHUKJALP7CZ6DANCNFSM4ICHGNYQ .

lperron commented 5 years ago

Shared search tree does not work on SAT, and is usually bad in general for other solvers. Laurent Perron | Operations Research | lperron@google.com | (33) 1 42 68 53 00

Le ven. 12 juil. 2019 à 10:06, Laurent Perron lperron@google.com a écrit :

Yes and yes. Laurent Perron | Operations Research | lperron@google.com | (33) 1 42 68 53 00

Le ven. 12 juil. 2019 à 09:59, mojinfu notifications@github.com a écrit :

i understand the reason is that “This tool contains only six algorithms for finding solutions，and every algorithm to another is can run on different thread . but single algorithm can not run on two thread “ is that correct?

— You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHub https://github.com/google/or-tools/issues/1420?email_source=notifications&email_token=ACUPL3MHMC54TF55ANC445TP7CZ6DA5CNFSM4ICHGNY2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGODZ2J32A#issuecomment-510959080, or mute the thread https://github.com/notifications/unsubscribe-auth/ACUPL3L26N4UKEOLCHUKJALP7CZ6DANCNFSM4ICHGNYQ .

mojinfu commented 5 years ago

The next version of ortools , will it be changed ? or it is still can not be ...

lperron commented 5 years ago

We are working very actively on this part. But we will never implement search tree sharing. Laurent Perron | Operations Research | lperron@google.com | (33) 1 42 68 53 00

Le ven. 12 juil. 2019 à 10:44, mojinfu notifications@github.com a écrit :

The next version of ortools , will it be changed ? or it is still can not be ...

— You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHub https://github.com/google/or-tools/issues/1420?email_source=notifications&email_token=ACUPL3LEMHKQD2F35VE2ZSTP7C7GNA5CNFSM4ICHGNY2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGODZ2NJYA#issuecomment-510973152, or mute the thread https://github.com/notifications/unsubscribe-auth/ACUPL3OOWPVXPWQGADPQBYLP7C7GNANCNFSM4ICHGNYQ .