Home » Author Archives: Geoffrey De Smet (page 2)

Author Archives: Geoffrey De Smet

Geoffrey De Smet (Red Hat) is the lead and founder of OptaPlanner. Before joining Red Hat in 2010, he was formerly employed as a Java consultant, an A.I. researcher and an enterprise application project lead. He has contributed to many open source projects (such as drools, jbpm, pressgang, spring-richclient, several maven plugins, weld, arquillian, ...). Since he started OptaPlanner in 2006, he’s been passionately addicted to planning optimization.

OptaPlanner – Scaling Vehicle Routing with Nearby Selection

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OptaPlanner 6.2 has made big step forward for the Vehicle Routing Problem (VRP), Traveling Salesman Problem (TSP) and similar use cases. The new feature nearby selection enables it to scale to bigger problems much more efficiently without sacrificing potential optimal solutions (which is common for inferior techniques). Let’s take a closer look at nearby selection with the Vehicle Routing Problem. ...

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Red Hat JBoss BRMS and BPMS Rich Client Framework demonstrating Polyglot Integration with GWT/Errai/UberFire and AngularJS

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Last week I published a blog highlighting a presentation I gave showing our rich client platform that has resulted from the work we have done within the BRMS and BPMS platforms, the productised versions of the Drools and jBPM projects. The presentation is all screenshots and videos, you can find the blog and the link to the slideshare here: “Red ...

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Prototyping an enterprise webapp at Devoxx Hackergarten

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For the 10th year in a row, I attended DevoxxBe. It’s my favorite Java conference, but the talk schedule isn’t always optimal: sometimes I want to see 2 great talks at the same time! So at the Hackergarten at Devoxx, between attending talks, a few of us started building a webapp to improve the schedule. We’re calling the prototype OptaConf ...

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OptaPlanner – Open benchmarks for the win

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Recently, there was some commotion on Twitter because a competitor heavily restricts publicising benchmarks of their Solver as part of their license. That might seem harsh, but I can understand the sentiment: when a competitor publicizes a benchmark report comparing our product against their own, I know we’re gonna get screwed. Unlike single product benchmarking, competitive benchmarking is inherently dishonest…​ ...

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OptaPlanner – Vehicle routing with real road distances

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In the real world, vehicles in a Vehicle Routing Problem (VRP) have to follow the roads: they can’t travel in a straight line from customer to customer. Most VRP research papers and demo’s happily ignore this implementation detail. As did I, in the past. Although using road distances (instead of air distances) doesn’t impact the NP-hard nature of a VRP ...

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Cheating on the N Queens benchmark

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Many Solver distributions include an N Queens example, in which n queens need to be placed on a n*n sized chessboard, with no attack opportunities. So when you’re looking for the fastest Solver, it’s tempting to use the N Queens example as a benchmark to compare those solvers. That’s a tragic mistake, because the N Queens problem is solvable in ...

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How much faster is Java 8?

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Java SE 8 was released yesterday. Traditionally, every new major JRE version comes with a free performance boost. Do we get another free lunch? And how big is the gain this time? Let’s benchmark it.             Benchmark methodology Run the same code with 3 different JRE versions (SunJDK 1.6.0_26, OpenJDK 1.7.0_51 and OpenJDK 1.8.0). The ...

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Can MapReduce solve planning problems?

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To solve a planning or optimization problem, some solvers tend to scale out poorly: As the problem has more variables and more constraints, they use a lot more RAM memory and CPU power. They can hit hardware memory limits at a few thousand variables and few million constraint matches. One way their users typically work around such hardware limits, is ...

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Drools 6 Performance with the PHREAK Algorithm

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Drools 6 introduces a new lazy matching algorithm. The details of that algorithm have been covered in two previous blogs: R.I.P. RETE time to get PHREAKY PHREAK Stack Based Evaluations and Backward Chaining The first article discussed performance and why the batch and lazy aspects of the algorithm, make it hard to compare.       “One final point on ...

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