h1. Migrating Petals ESB runtime

No migration is required. Just reinstall your Petals topology with the Petals ESB 5.4.x runtime.

h1. Migrating your services

At a runtime level, a large majority of service units running on Petals 5.3.x are compatible with Petals 5.4.x and do not require changes with the exception of:
* [Petals SE Camel service units|petalscomponents:Petals-SE-Camel 1.4.0+#migrationguide],
* [Petals SE POJO service units|petalscomponents:Petals-SE-POJO 2.8.0+#migrationguide].

At a development level, all service units need changes at unit test level because:
* API Jakarta EE 9 is now used by Petals ESB instead of API Java EE,
* and, all Petals component JUnit framework are based on JUnit 5 now:
** [Petals SE Camel service units|petalscomponents:Petals-SE-Camel 1.4.0+#migrationguide],
** [Petals SE Flowable service units|petalsseflowable150:Petals-SE-Flowable 1.5.0+#migrationguide],
** [Petals SE Mapping service units|petalscomponents:Petals SE Mapping 1.3.0+#migrationguide],
** [Petals SE POJO service units|petalscomponents:Petals-SE-POJO 2.8.0+#migrationguide].