Decision Optimization

#DecisionOptimization

Can you show the engine log for one of the runs that fail? You might be running out of memory during tree search. Also check this chapter in the user manual.

------------------------------
Daniel Junglas
------------------------------

Original Message:
Sent: Tue June 02, 2020 08:47 AM
From: Shibin K T
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

hi team,

Attaching the screen shot of the error I am facing with CPLEX IDE.

I have already tried few things:
1.In run configuration settings allocating more memory to the problem : same error
2. Tried running on OPL
3. tried running same model on cloud Error: Failed - Engine error.

My model has 2088400 variables and 3587352 constraints, and I have laptop with 8GB RAM

Same problem runs for small set of inputs and takes around 10 mins to get to an integer solution.

Kindly suggest or guide me through overcoming this problem. 
Regards and Thanks

#DecisionOptimization

Hi Daniel,
Thank you very much for your response.

I ran this model again with enabling memory reduction switch.
I am still facing same problem.
I will try other options available also and will share with you log files.

Sharing with you the log file from last run.

Regards and Thanks
Deep Kankaria

------------------------------
Shibin K T
------------------------------

Original Message:
Sent: Tue June 02, 2020 11:36 AM
From: Daniel Junglas
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

Can you show the engine log for one of the runs that fail? You might be running out of memory during tree search. Also check this chapter in the user manual.

------------------------------
Daniel Junglas

Original Message:
Sent: Tue June 02, 2020 08:47 AM
From: Shibin K T
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

hi team,

Attaching the screen shot of the error I am facing with CPLEX IDE.

I have already tried few things:
1.In run configuration settings allocating more memory to the problem : same error
2. Tried running on OPL
3. tried running same model on cloud Error: Failed - Engine error.

My model has 2088400 variables and 3587352 constraints, and I have laptop with 8GB RAM

Same problem runs for small set of inputs and takes around 10 mins to get to an integer solution.

Kindly suggest or guide me through overcoming this problem. 
Regards and Thanks

#DecisionOptimization

Ok, it seems your model is too big for 8 threads. Each thread requires a deep copy of the model in memory to work with. You don't even get to the start of tree search, so those memory reduction switches have no chance to kick in.

In order to reduce the memory requirements, reduce the number of threads. If nothing else helps, reduce the number of threads to 1. I suggest to keep the memory reduction and nodes-on-disk switches to avoid running out of memory in tree search later.

ADDENDUM: As can be seen in your log file, your model as 115581194 non-zero matrix elements. For one element you need at least 16 bytes to store it (8 bytes for the non-zero value, 8 bytes for the non-zero index). So just to store the matrix, you need 1849299104 bytes, which is roughly 1.7 GB. And then CPLEX has to store much more information. Given that CPLEX needs a deep copy of that information for each thread, this explains pretty well why 8 GB are not enough for 8 threads. I guess you can use at most 4 threads, more realistically 2 or 3.

------------------------------
Daniel Junglas
------------------------------

Original Message:
Sent: Wed June 03, 2020 03:52 AM
From: Shibin K T
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

Hi Daniel,
Thank you very much for your response.

I ran this model again with enabling memory reduction switch.
I am still facing same problem.
I will try other options available also and will share with you log files.

Sharing with you the log file from last run.

Regards and Thanks
Deep Kankaria

------------------------------
Shibin K T

Original Message:
Sent: Tue June 02, 2020 11:36 AM
From: Daniel Junglas
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

Can you show the engine log for one of the runs that fail? You might be running out of memory during tree search. Also check this chapter in the user manual.

------------------------------
Daniel Junglas

Original Message:
Sent: Tue June 02, 2020 08:47 AM
From: Shibin K T
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

hi team,

Attaching the screen shot of the error I am facing with CPLEX IDE.

I have already tried few things:
1.In run configuration settings allocating more memory to the problem : same error
2. Tried running on OPL
3. tried running same model on cloud Error: Failed - Engine error.

My model has 2088400 variables and 3587352 constraints, and I have laptop with 8GB RAM

Same problem runs for small set of inputs and takes around 10 mins to get to an integer solution.

Kindly suggest or guide me through overcoming this problem. 
Regards and Thanks

#DecisionOptimization

Hi Daniel,

Hope you are safe.
Thank you for your help,

I tried with 4 and 3 threads it was crashing, but with 2 threads its running and it has been 11 hrs still model is running.
Positive side is its not crashing, negative side is run time.
I will try to run it on 64 GB RAM machine with 8 threads, mean while can you suggest any parameter changes to reduce run time and make it faster.
I just want an integer feasible solution.

Regards and thanks
Deep Kankaria

------------------------------
Shibin K T
------------------------------

Original Message:
Sent: Wed June 03, 2020 05:45 AM
From: Daniel Junglas
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

Ok, it seems your model is too big for 8 threads. Each thread requires a deep copy of the model in memory to work with. You don't even get to the start of tree search, so those memory reduction switches have no chance to kick in.

In order to reduce the memory requirements, reduce the number of threads. If nothing else helps, reduce the number of threads to 1. I suggest to keep the memory reduction and nodes-on-disk switches to avoid running out of memory in tree search later.

ADDENDUM: As can be seen in your log file, your model as 115581194 non-zero matrix elements. For one element you need at least 16 bytes to store it (8 bytes for the non-zero value, 8 bytes for the non-zero index). So just to store the matrix, you need 1849299104 bytes, which is roughly 1.7 GB. And then CPLEX has to store much more information. Given that CPLEX needs a deep copy of that information for each thread, this explains pretty well why 8 GB are not enough for 8 threads. I guess you can use at most 4 threads, more realistically 2 or 3.

------------------------------
Daniel Junglas

Original Message:
Sent: Wed June 03, 2020 03:52 AM
From: Shibin K T
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

Hi Daniel,
Thank you very much for your response.

I ran this model again with enabling memory reduction switch.
I am still facing same problem.
I will try other options available also and will share with you log files.

Sharing with you the log file from last run.

Regards and Thanks
Deep Kankaria

------------------------------
Shibin K T

Original Message:
Sent: Tue June 02, 2020 11:36 AM
From: Daniel Junglas
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

Can you show the engine log for one of the runs that fail? You might be running out of memory during tree search. Also check this chapter in the user manual.

------------------------------
Daniel Junglas

Original Message:
Sent: Tue June 02, 2020 08:47 AM
From: Shibin K T
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

hi team,

Attaching the screen shot of the error I am facing with CPLEX IDE.

I have already tried few things:
1.In run configuration settings allocating more memory to the problem : same error
2. Tried running on OPL
3. tried running same model on cloud Error: Failed - Engine error.

My model has 2088400 variables and 3587352 constraints, and I have laptop with 8GB RAM

Same problem runs for small set of inputs and takes around 10 mins to get to an integer solution.

Kindly suggest or guide me through overcoming this problem. 
Regards and Thanks

#DecisionOptimization

In case you only want one single feasible solution, you can set the MIP solution limit to 1. With that CPLEX will stop as soon as feasible solution is found.

------------------------------
Daniel Junglas
------------------------------

Original Message:
Sent: Fri June 05, 2020 03:09 AM
From: Shibin K T
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

Hi Daniel,

Hope you are safe.
Thank you for your help,

I tried with 4 and 3 threads it was crashing, but with 2 threads its running and it has been 11 hrs still model is running.
Positive side is its not crashing, negative side is run time.
I will try to run it on 64 GB RAM machine with 8 threads, mean while can you suggest any parameter changes to reduce run time and make it faster.
I just want an integer feasible solution.

Regards and thanks
Deep Kankaria

------------------------------
Shibin K T

Original Message:
Sent: Wed June 03, 2020 05:45 AM
From: Daniel Junglas
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

Ok, it seems your model is too big for 8 threads. Each thread requires a deep copy of the model in memory to work with. You don't even get to the start of tree search, so those memory reduction switches have no chance to kick in.

In order to reduce the memory requirements, reduce the number of threads. If nothing else helps, reduce the number of threads to 1. I suggest to keep the memory reduction and nodes-on-disk switches to avoid running out of memory in tree search later.

ADDENDUM: As can be seen in your log file, your model as 115581194 non-zero matrix elements. For one element you need at least 16 bytes to store it (8 bytes for the non-zero value, 8 bytes for the non-zero index). So just to store the matrix, you need 1849299104 bytes, which is roughly 1.7 GB. And then CPLEX has to store much more information. Given that CPLEX needs a deep copy of that information for each thread, this explains pretty well why 8 GB are not enough for 8 threads. I guess you can use at most 4 threads, more realistically 2 or 3.

------------------------------
Daniel Junglas

Original Message:
Sent: Wed June 03, 2020 03:52 AM
From: Shibin K T
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

Hi Daniel,
Thank you very much for your response.

I ran this model again with enabling memory reduction switch.
I am still facing same problem.
I will try other options available also and will share with you log files.

Sharing with you the log file from last run.

Regards and Thanks
Deep Kankaria

------------------------------
Shibin K T

Original Message:
Sent: Tue June 02, 2020 11:36 AM
From: Daniel Junglas
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

Can you show the engine log for one of the runs that fail? You might be running out of memory during tree search. Also check this chapter in the user manual.

------------------------------
Daniel Junglas

Original Message:
Sent: Tue June 02, 2020 08:47 AM
From: Shibin K T
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

hi team,

Attaching the screen shot of the error I am facing with CPLEX IDE.

I have already tried few things:
1.In run configuration settings allocating more memory to the problem : same error
2. Tried running on OPL
3. tried running same model on cloud Error: Failed - Engine error.

My model has 2088400 variables and 3587352 constraints, and I have laptop with 8GB RAM

Same problem runs for small set of inputs and takes around 10 mins to get to an integer solution.

Kindly suggest or guide me through overcoming this problem. 
Regards and Thanks

#DecisionOptimization

Hi Daniel,

I have one more question.

I tried to run this model on DOcplex cloud in cloud also it failed, may I know potential reason for its failure or is there any document you can guide us through?

Regards and Thanks
Deep Kankaria


------------------------------
Shibin K T
------------------------------

Original Message:
Sent: Wed June 03, 2020 05:45 AM
From: Daniel Junglas
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

Ok, it seems your model is too big for 8 threads. Each thread requires a deep copy of the model in memory to work with. You don't even get to the start of tree search, so those memory reduction switches have no chance to kick in.

In order to reduce the memory requirements, reduce the number of threads. If nothing else helps, reduce the number of threads to 1. I suggest to keep the memory reduction and nodes-on-disk switches to avoid running out of memory in tree search later.

ADDENDUM: As can be seen in your log file, your model as 115581194 non-zero matrix elements. For one element you need at least 16 bytes to store it (8 bytes for the non-zero value, 8 bytes for the non-zero index). So just to store the matrix, you need 1849299104 bytes, which is roughly 1.7 GB. And then CPLEX has to store much more information. Given that CPLEX needs a deep copy of that information for each thread, this explains pretty well why 8 GB are not enough for 8 threads. I guess you can use at most 4 threads, more realistically 2 or 3.

------------------------------
Daniel Junglas

Original Message:
Sent: Wed June 03, 2020 03:52 AM
From: Shibin K T
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

Hi Daniel,
Thank you very much for your response.

I ran this model again with enabling memory reduction switch.
I am still facing same problem.
I will try other options available also and will share with you log files.

Sharing with you the log file from last run.

Regards and Thanks
Deep Kankaria

------------------------------
Shibin K T

Original Message:
Sent: Tue June 02, 2020 11:36 AM
From: Daniel Junglas
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

Can you show the engine log for one of the runs that fail? You might be running out of memory during tree search. Also check this chapter in the user manual.

------------------------------
Daniel Junglas

Original Message:
Sent: Tue June 02, 2020 08:47 AM
From: Shibin K T
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

hi team,

Attaching the screen shot of the error I am facing with CPLEX IDE.

I have already tried few things:
1.In run configuration settings allocating more memory to the problem : same error
2. Tried running on OPL
3. tried running same model on cloud Error: Failed - Engine error.

My model has 2088400 variables and 3587352 constraints, and I have laptop with 8GB RAM

Same problem runs for small set of inputs and takes around 10 mins to get to an integer solution.

Kindly suggest or guide me through overcoming this problem. 
Regards and Thanks

#DecisionOptimization

I think the first thing to do is to figure out why it failed. Check the logfile etc. for error messages.

------------------------------
Daniel Junglas
------------------------------

Original Message:
Sent: Fri June 05, 2020 03:18 AM
From: Shibin K T
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

Hi Daniel,

I have one more question.

I tried to run this model on DOcplex cloud in cloud also it failed, may I know potential reason for its failure or is there any document you can guide us through?

Regards and Thanks
Deep Kankaria


------------------------------
Shibin K T

Original Message:
Sent: Wed June 03, 2020 05:45 AM
From: Daniel Junglas
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

Ok, it seems your model is too big for 8 threads. Each thread requires a deep copy of the model in memory to work with. You don't even get to the start of tree search, so those memory reduction switches have no chance to kick in.

In order to reduce the memory requirements, reduce the number of threads. If nothing else helps, reduce the number of threads to 1. I suggest to keep the memory reduction and nodes-on-disk switches to avoid running out of memory in tree search later.

ADDENDUM: As can be seen in your log file, your model as 115581194 non-zero matrix elements. For one element you need at least 16 bytes to store it (8 bytes for the non-zero value, 8 bytes for the non-zero index). So just to store the matrix, you need 1849299104 bytes, which is roughly 1.7 GB. And then CPLEX has to store much more information. Given that CPLEX needs a deep copy of that information for each thread, this explains pretty well why 8 GB are not enough for 8 threads. I guess you can use at most 4 threads, more realistically 2 or 3.

------------------------------
Daniel Junglas

Original Message:
Sent: Wed June 03, 2020 03:52 AM
From: Shibin K T
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

Hi Daniel,
Thank you very much for your response.

I ran this model again with enabling memory reduction switch.
I am still facing same problem.
I will try other options available also and will share with you log files.

Sharing with you the log file from last run.

Regards and Thanks
Deep Kankaria

------------------------------
Shibin K T

Original Message:
Sent: Tue June 02, 2020 11:36 AM
From: Daniel Junglas
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

Can you show the engine log for one of the runs that fail? You might be running out of memory during tree search. Also check this chapter in the user manual.

------------------------------
Daniel Junglas

Original Message:
Sent: Tue June 02, 2020 08:47 AM
From: Shibin K T
Subject: I am trying to run model on CPLEX IDE and this error pops up "Opl process is not responding, you must relaunch the run configuration"

hi team,

Attaching the screen shot of the error I am facing with CPLEX IDE.

I have already tried few things:
1.In run configuration settings allocating more memory to the problem : same error
2. Tried running on OPL
3. tried running same model on cloud Error: Failed - Engine error.

My model has 2088400 variables and 3587352 constraints, and I have laptop with 8GB RAM

Same problem runs for small set of inputs and takes around 10 mins to get to an integer solution.

Kindly suggest or guide me through overcoming this problem. 
Regards and Thanks

#DecisionOptimization