• United States
IBM?
  • Site map
IBM? developerWorks   Developer Centers
  • Marketplace

  • Close
    Search
  • Sign in
    • Sign in
    • Register
  • IBM Navigation
dW Answers
  • Spaces
    • Blockchain
    • IBM Cloud platform
    • Internet of Things
    • Predictive Analytics
    • Watson
    • See all spaces
  • Tags
  • Users
  • Badges
  • FAQ
  • Help
Close

Name

developerWorks

  • Learn
  • Develop
  • Connect

Discover IBM

  • ConnectMarketplace
  • Products
  • Services
  • Industries
  • Careers
  • Partners
  • Support
10.190.13.206

Decision Optimization×

Refine your search by using the following advanced search options.

Criteria Usage
Questions with keyword1 or keyword2 keyword1 keyword2
Questions with a mandatory word, e.g. keyword2 keyword1 +keyword2
Questions excluding a word, e.g. keyword2 keyword1 -keyword2
Questions with keyword(s) and a specific tag keyword1 [tag1]
Questions with keyword(s) and either of two or more specific tags keyword1 [tag1] [tag2]
To search for all posts by a user or all posts with a specific tag, start typing and choose from the suggestion list. Do not use a plus or minus sign with a tag, e.g., +[tag1].
  • Ask a question

CPLEX 12.7 Parameter Tuning

270005G8Q3 gravatar image
Question by G8Q3_SV  (7) | Jan 16, 2017 at 01:22 AM performancedocplexcloudoutofmemoryerrortuningheuristics

Hello CPLEX Experts,

I have run some of my problems in CPLEX 12.7 Cloud using the DropSolve. This was run after purchasing the 60 GB RAM Configuration. I have some questions related to its performance

1) Default CPLEX 12.7 parameters wasn't helpful at all. I have attached log file - "CPLEX DEFAULT" link text

2) I then disabled all the cuts and solved Root Relaxation using Barrier . The progress of solver was better than default but it has given Out of Memory Error. Please find the attachment "CUTS OFF CPLEX 12.7 LOG" and "Out of Memory" link text alt text

3) I had solved this problem using my own technique in CPLEX old version and could reach the good solution faster. I first solved the LP relaxation first and then fixed some of the variables which are close to integer values and then solve the Original MIP with this as an initial solution. Please find the attachment "CPLEX old verison Heuristic -Log" link text

My first question is using CPLEX Parameters can I get the solution which I have got using the heuristics and how to avoid this out of memory problem ? Do I need to purchase a higher configuration in DOCLOUD which I cant see in the list of configuration for Pay-As-you go plan?

My Second question is to implement the technique which I use in CPLEX older version is it possible on the same JobID ? I don't wish to run three different jobs one for solving LP relaxation , one for solving with fixed variables and lastly for the original MIP with initial solution . Also this technique fails sometimes in closing the optimality gap and this also consumes huge amount of RAM.

If required I can share the problem file as well.

out-of-memory.png (32.7 kB)
cplex-default.log (4.0 kB)
cuts-off-cplex-127-log.log (23.7 kB)
cplex-old-verison-heuristic-log.txt (14.4 kB)

People who like this

  0
Comment
10 |3000 characters needed characters left characters exceeded
  • Viewable by all users
  • Viewable by moderators
  • Viewable by moderators and the original poster

1 reply

  • Sort: 
270002S4SX gravatar image

Answer by DanielJunglas (915) | Jan 16, 2017 at 02:26 AM

The best solution found by CPLEX should be available no matter how/why CPLEX stopped. This solution should be available in the "Results" tab. Is it not there in your case?

One thing you could try to avoid out of memory so early in the search is to reduce the number of threads. By default CPLEX will use 10 threads. Since each thread requires a deep copy of the model and your model is rather large, this can consume a significant amount of memory. I suggest to try running with CPX_PARAM_THREADS set to 9 or 8 and see if this works any better. You could also try to set CPX_PARAM_PROBE to more aggressive values to get an even smaller presolved model.

In DropSolve you can only have one solve per Job. I can see two different ways to get your heuristic working on the cloud:

  1. Don't use DropSolve but the REST API and its Java and/or Python wrappers. With this you can easily create/control multiple jobs and basically write some small code that implements your strategy while performing all the solves on the cloud.

  2. Implement everything (initial solve, rounding, fixed solve, solve with MIP start) in OPLScript and then drop the resulting .mod file to the cloud. Not sure if this is feasible in your case.

Would you be willing to share your model with the engine developers? Maybe we can take a closer look and suggest other alternatives to solve this model faster.

Comment

People who like this

  0   Show 2   Share
10 |3000 characters needed characters left characters exceeded
  • Viewable by all users
  • Viewable by moderators
  • Viewable by moderators and the original poster
270005G8Q3 gravatar image G8Q3_SV (7)   Jan 16, 2017 at 10:38 PM 0
Share

Thank you Daniel for your suggestions. Could you please provide us the link/email to share the model file. I shall gzip the file and send it.

270002S4SX gravatar image DanielJunglas (915) G8Q3_SV (7)   Jan 17, 2017 at 12:24 AM 0
Share

Please send it to daniel(dot)junglas(at)de(dot)ibm(dot)com. If the file is too big for email we can work out something else.

Follow this question

103 people are following this question.

Show
Hide
270005G8Q3 gravatar image
270000GWTC gravatar image
270000FDR4 gravatar image
270000XYBA gravatar image
110000716N gravatar image
270006XPGB gravatar image
12000089VF gravatar image
270007S0YR gravatar image
0 gravatar image
270000HCSB gravatar image
270007J4V5 gravatar image
060000TPFC gravatar image
270007TC7S gravatar image
270007N89G gravatar image
270007E13S gravatar image
270003G2C2 gravatar image
1200006P5U gravatar image
2700077Y16 gravatar image
060000GS8A gravatar image
27000412BP gravatar image
270003TDDU gravatar image
110000A7Q4 gravatar image
0600026V6R gravatar image
270007KSPS gravatar image
120000GKJX gravatar image
270005CRQH gravatar image
270002DX0R gravatar image
1100006DS0 gravatar image
120000PKE0 gravatar image
2700071CQ3 gravatar image
060000JCQ6 gravatar image
120000KBJ0 gravatar image
2700048B8W gravatar image
2700077GBQ gravatar image
2700050NEH gravatar image
270001KHBU gravatar image
270003U2JX gravatar image
1200007P68 gravatar image
060000PBF9 gravatar image
310000C3WF gravatar image
120000FVD3 gravatar image
2700078CT8 gravatar image
120000DJQR gravatar image
110000CPVN gravatar image
100000PUHW gravatar image
060000UPGT gravatar image
3100012P1N gravatar image
270005EH6S gravatar image
2700064F5C gravatar image
270002YGE4 gravatar image
120000K2Y8 gravatar image
31000066QG gravatar image
310001XRBV gravatar image
310000AVXW gravatar image
100000AYJ5 gravatar image
0600006FD4 gravatar image
270007817Q gravatar image
3100022S3B gravatar image
270003TGA5 gravatar image
0600029FSS gravatar image
270000S0MP gravatar image
270000W33V gravatar image
110000AF44 gravatar image
270003TTGW gravatar image
50WJRKN03C gravatar image
270001QB6R gravatar image
270000FXVC gravatar image
27000648WT gravatar image
270000CTQS gravatar image
310002CN85 gravatar image
2700061C57 gravatar image
110000C59H gravatar image
50T5CPU10M gravatar image
50G77GYY6D gravatar image
0600014AB6 gravatar image
3100026SAA gravatar image
3100015MKH gravatar image
310002BBMH gravatar image
310001F4NR gravatar image
270003XXWM gravatar image
270003Y1M4 gravatar image
31000098RE gravatar image
270006TJHJ gravatar image
310002BHAD gravatar image
270007QY2W gravatar image
27000057X1 gravatar image
2700013TF4 gravatar image
270001Y6MF gravatar image
2700039TS4 gravatar image
270001YQ13 gravatar image
50J5B74J8S gravatar image
5070VN6V9H gravatar image
270004MKK4 gravatar image
310000A2A3 gravatar image
27000341TY gravatar image
3100009MTN gravatar image
27000139QX gravatar image
270004CP3K gravatar image
270005QYTJ gravatar image
2700021DTG gravatar image
270002G414 gravatar image
310000DQCQ gravatar image
270002S4SX gravatar image

Answers

Answers & comments

Related questions

where to start tuning the JVM and the Operating System to get the maximum performance out of my WebSphere Application server 2 Answers

How to tune BPM if you find 'Local Cache Hits' using longer time in the instrumentation log? 1 Answer

I am getting TCP/IP OMPROUTE adjacency failures; is there any performance tuning I can do? 1 Answer

What type of analysis can be done on IBM BPM event manager history data? 1 Answer

Why does the JVM setting -Xdisableexplicitgc cause the process size to grow and eventually cause Native OutOfMemory? 1 Answer

  • Contact
  • Privacy
  • Terms of use
  • Accessibility
  • Report Abuse
  • Cookie Preferences

Powered by AnswerHub

Authentication check. Please ignore.
  • Anonymous
  • Sign in
  • Create
  • Ask a question
  • Spaces
  • API Connect
  • Application Performance Management
  • Appsecdev
  • BPM
  • Blockchain
  • Business Transaction Intelligence
  • CAPI
  • CAPI SNAP
  • CICS
  • Cloud Analytics
  • Cloud Automation
  • Cloud Object Storage
  • Cloud marketplace
  • Collaboration
  • Content Services (ECM)
  • Continuous Testing
  • Courses
  • Customer Experience Analytics
  • DB2 LUW
  • DataPower
  • Decision Optimization
  • DevOps Services
  • Digital Commerce
  • Digital Experience
  • Finance
  • Global Entrepreneur Program
  • Hadoop
  • IBM Cloud platform
  • IBM Design
  • IBM Forms Experience Builder
  • IBM Maximo Developer
  • IBM StoredIQ
  • IBM StoredIQ-Cartridges
  • IIDR
  • ITOA
  • InformationServer
  • Integration Bus
  • Internet of Things
  • Kenexa
  • Linux on Power
  • LinuxONE
  • MDM
  • Mainframe
  • Messaging
  • Node.js
  • ODM
  • Open
  • PowerAI
  • PowerVC
  • Predictive Analytics
  • Product Insights
  • PureData for Analytics
  • Push
  • QRadar App Development
  • Run Book Automation
  • Search Insights
  • Storage
  • Streamsdev
  • Supply Chain Business Network
  • Supply Chain Insights
  • Swift
  • UBX Capture
  • Universal Behavior Exchange
  • UrbanCode
  • WASdev
  • WSRR
  • Watson
  • Watson Campaign Automation
  • Watson Content Hub
  • Watson Marketing Insights
  • dW Answers Help
  • dW Premium
  • developerWorks Sandbox
  • developerWorks Team
  • Watson Health
  • More
  • Tags
  • Questions
  • Users
  • Badges