Spring is in the air, and so is another release of Timefold Solver. And this time, it's a big one! For the Community Edition, we have prepared the following features:

• List variables now allow for unassigned values. Say goodbye to the "dummy vehicle" pattern, say hello to the performance improvements that come from it!
• Spring Boot users among you can now easily generate native images, as was already possible for Quarkus.
• ConstraintVerifier can now test for justifications and indictments, allowing you to write tests that will give you even more confidence in your constraints than was possible before.
• We have exposed new metrics that allow you to better monitor the currently running solver(s).
• We have brought the usual bugfixes and dependency upgrades.

On top of all that, our Enterprise Edition customers can enjoy some exclusive goodies:

• Automatic node sharing. Use cases with a large number of complex constraints may run much faster without any changes to your code. In our benchmarks, we have seen improvements in score calculation speed of up to 100 % on some data sets.
• Nearby Selection can now be enabled with a single switch in your configuration, as opposed to the cumbersome configuration of old. If you're still not using Nearby Selection for your large routing problems, you're missing out on cost savings coming from significantly improved solutions!

Going forward, we will be publishing an Upgrade Recipe to let you know of any things you may or may not run into when upgrading to the latest version of Timefold Solver. It's a good read!

Changelog

🚀 Features

• Support unassigned elements for list variables, closes #573
• Add support for Spring Boot native image, closes #609
• Automatic node sharing for ConstraintProvider, closes #685
• Add the nearby-distance-meter-class property for Quarkus and Spring, closes #687
• Enable Nearby Selection for non-empty move selectors configuration, closes #684
• Add Nearby configuration by exception, closes #673
• Support getting score calculation count and speed for SolverJob, closes #621
• Expose entity, variable and value counts in the logs and metrics, closes #671
• Add penalty methods for long and BigDecimal values without match weighter, closes #656
• Extend SingleConstraintAssertion to check Justification/indictment, closes #659
• Add withClassLoader(...) method to SolverConfig, closes #691 #695

🐛 Fixes

• Do not recalculate problem size statistics in Benchmarker
• Pass provided ClassLoader to ServiceLoader, closes #690 #692

🧰 Tasks

• Improve error messages from loading YAML files, closes #637

📝 Documentation

• Add upgrade and migration section, closes #686

Contributors

We'd like to thank the following people for their contributions:

• Christopher Chianelli
• Frederico Gonçalves (@zepfred)
• Geoffrey De Smet
• GitHub
• Lukáš Petrovický (@triceo)
• Pieter De Schepper
• dependabot[bot] (@dependabot[bot])
• marinier

Timefold Solver Community Edition is an open source project, and you are more than welcome to contribute as well! For more, see Contributing.

Should your business need to scale to truly massive data sets or require enterprise-grade support, check out Timefold Solver Enterprise Edition.

How to use Timefold Solver

To see Timefold Solver in action, check out the quickstarts.

With Maven or Gradle, add the ai.timefold.solver : timefold-solver-core : 1.8.0 dependency in your pom.xml to get started.

You can also import the Timefold Solver Bom (ai.timefold.solver : timefold-solver-bom : 1.8.0) to avoid duplicating version numbers when adding other Timefold Solver dependencies later on.

Additional notes

The changelog and the list of contributors above are automatically generated. It excludes contributions to certain areas of the repository, such as CI and build automation. This is done for the sake of brevity and to make the user-facing changes stand out more.