Need suggestions for Play framework version to use

[sjha1010]

We are migrating one of our applications to higher versions of current software stack. On FMO, we will be using OpenJDK 21, sbt 1.9.8. It will be running on RHEL 9.5. Which version of play I should be using now?

[mkurz]

You should use the latest version of the 3.0.x release which currently is 3.0.11: https://github.com/playframework/playframework/releases/tag/3.0.11

From which version do you upgrade?
Make sure you follow the migration guides for each major release:
for example for the 2.9 majore release: https://www.playframework.com/documentation/3.0.x/Migration29

[sjha1010]

Could you please give little background on akka and pekko?
And what would you suggest what we should go for ?

[mkurz]

I would do following

• Upgrade to 2.3.x by following its migration guide: https://www.playframework.com/documentation/3.0.x/Migration23
• Also read the 2.3.x Highlights: https://www.playframework.com/documentation/3.0.x/Highlights23

If that works, move forward and migrate to 2.4.x:

• Upgrade to 2.4.x by following its migration guide: https://www.playframework.com/documentation/3.0.x/Migration24
• Also read the 2.4.x Highlights: https://www.playframework.com/documentation/3.0.x/Highlights23

If that works, move on to the next releases, again and again:

2.5:

• https://www.playframework.com/documentation/3.0.x/Migration25
• https://www.playframework.com/documentation/3.0.x/Highlights25

2.6:

• https://www.playframework.com/documentation/3.0.x/Migration26
• https://www.playframework.com/documentation/3.0.x/Highlights26

2.7:

• https://www.playframework.com/documentation/3.0.x/Migration27
• https://www.playframework.com/documentation/3.0.x/Highlights27

2.8:

• https://www.playframework.com/documentation/3.0.x/Migration28
• https://www.playframework.com/documentation/3.0.x/Highlights28

2.9:

• https://www.playframework.com/documentation/3.0.x/Migration29
• https://www.playframework.com/documentation/3.0.x/Highlights29

3.0:

• https://www.playframework.com/documentation/3.0.x/Migration30
• https://www.playframework.com/documentation/3.0.x/Highlights30

If you use LLMs just point it to the migration guides and to the highlights. Let it finish a migration, when that works, move forward to the next migration.

[mkurz]

Could you please give little background on akka and pekko?
And what would you suggest what we should go for ?

Just choose Pekko (that happens anyway when you upgrade to Play 3.0)

[sjha1010]

Can't I move directly from 2.2.1 to 3.0.6 ?
What would the challenges if I do this ?

[mkurz]

You can do that. Just give it a try. However there will be alot of code breaking. So you will have to follow all the migration guide anyway.

[Squeng]

First, whether you skip Play versions or not, you may want to make sure that your app does not depend on Play all over the place (anymore). Check out the "Towards Hexagonal Architecture" series at https://codeartify.substack.com/ (which uses Spring Boot in its examples).

If you have a monolith or a microservice, you'll end up with one hexagon (cf. https://github.com/Squoss/Twotle/tree/main/beapi/hexagon for example). If you have a modulith, you'll end up with one hexagon per module (cf. https://github.com/Deposplit/deposplit.com/tree/main/hexagons for example).

[arnabnandy7]

For a production application running on OpenJDK 21, I’d target the latest Play 3.0.x release, currently 3.0.11, rather than starting with 3.0.6.

Play 3 uses Apache Pekko instead of Akka. Pekko is an Apache-licensed fork of Akka 2.6, created after Akka changed its licensing. So there isn’t really an Akka-versus-Pekko decision when upgrading to Play 3—the move to Pekko comes with the framework.

You can go from Play 2.2.1 directly to Play 3.0.x as the final destination, but it’s a significant migration. Even if you skip installing or deploying the intermediate Play versions, you’ll still need to account for the breaking changes introduced in each release.

I’d work through the migration guides in order:

2.2 → 2.3 → 2.4 → 2.5 → 2.6 → 2.7 → 2.8 → 2.9 → 3.0

At each stage, get the application compiling, update the affected dependencies and plugins, and run the tests. Keeping each successful stage as a separate commit will make failures much easier to trace. You don’t need to deploy every intermediate version.

Before starting, check whether all your essential Play plugins and third-party libraries have Play 3 and Pekko-compatible versions. In an application this old, unsupported plugins are likely to be a bigger challenge than Play’s own API changes.

In short, I’d choose the latest Play 3.0.x release with Pekko, but approach the upgrade as a series of small, testable migrations instead of one large change.