| [auto-iwg] Dealing with large models: a mix between modularization and model repository. Was WP2 Telco Results |
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Dear Polarsys and Auto IWG people, Please find hereafter a summary of an interesting discussion on the Auto IWG mailing list about the big models issue and the use of CDO. In the following discussion after this email, Christof Hammel from Bosch elaborates about the idea of model modularization: <quote>This is an interesting discussion about the topic "modularization of models". We at Bosch call this "file distribution" and we also have a well-defined distribution of the data across different files. This is a pretty well-proven concept and it would be an interesting idea to have a kind of standardization of this "file distribution". Maybe the Auto-IWG could come up with a proposal and inject this back to Autosar.</quote> I strongly believe this is a topic on which we can establish fruitful collaboration between Polarsys members and Auto-IWG members. I know that on both side, the issue of managing big models split into smaller parts is addressed, as well as the issue of using a model repository like CDO for collaboration. I think that if best practices for "model modularization" and CDO based collaboration would be standardized, it could partly be made "in common" between our two groups. I crosspost on the two mailing lists so that we can continue the discussion. Regards, Gaël Blondelle OPEES project leader Obeo -------- Message original --------
Dear all, this email is to inform you about the outcome of the telco in WP2 on experiences with CDO. Christian Schenk (Bosch) and Andreas Rytina (itemis) reported on their experience in using CDO that results from a project with a size of about 1-person-year. Eike Stepper (project lead of CDO) joined as a guest and commented the results and provided feedback on possible improvements. In summary the results indicate that the use of CDO in the specific use case resulted in an overhead in computation time of about factor 6. Interestingly this factor also occurs if the involved model fully fitted into memory and was already pre-fetched. This factor might be significantly lower for other use cases. Nevertheless there will always be a significant overhead in time when using CDO. Estimates in the discussion ranged around a factor 2-3, but only specific test cases could reveal exact numbers. Additionally the actual overhead greatly depends on a specific use case and on how much the client is optimized towards using CDO. For Bosch the final solution was to switch to a 64bit JVM, since the models currently in use at Bosch fit in the memory of a 4GB machine. In conclusion CDO (as well as other model repositories) will not be a "silver bullet" that solves all problems involved in the usage of big models in terms of memory consumption and computation time. It is a very hard problem to be able to handle large models efficiently. To be able to find a solution in the AutoIWG context a first and mandatory step should be to discuss the requirements of the participants in terms of maximum model size. Additionally it was pointed out in the telco that there is a number of other benefits that could require the use of model repository apart from the aforementioned challenges. Collaborative work on models, improved support for transactions and improved versioning and change tracking/diffing have been discussed in the telco as potential benefits. We suggest to add a discussion about the requirements for WP2 in terms of maximum model size and about other potential requirements (e.g. collaborative work) on the agenda of the next face-to-face meeting of the IWG. Best Regards, Maximilian Kögel -- Dr. Maximilian Kögel Software Engineer / Consultant / General Manager EclipseSource Munich Email: mkoegel@xxxxxxxxxxxxxxxxx Web: http://eclipsesource.com/munich Mobil: +49 176 223 619 18 Phone: +49 89 21 555 301 Fax: +49 89 21 555 302 EclipseSource München GmbH Agnes-Pockels-Bogen 1 80992 München General Managers: Dr. Jonas Helming, Dr. Maximilian Kögel Registered Office: Sailerstraße 5, 80809 München, Commercial Register München, HRB 191789 |
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