h1. Migrating Petals ESB runtime

No migration is required. Just reinstall your Petals topology with the Petals ESB 5.3.x runtime.

h1. Migrating your services

At a runtime level, a large majority of service units running on Petals 5.2.x are compatible with Petals 5.3.x and do not require changes with the exception of:
* [Petals SE Camel service units|petalscomponents:Petals-SE-Camel 1.3.0+#migrationguide],
* [Petals SE POJO service units|petalscomponents:Petals-SE-POJO 2.7.0+#migrationguide].

At a development level, all service units having unit tests based on a Petals component JUnit framework and handling placeholder need changes:
* [Petals SE Camel service units|petalscomponents:Petals-SE-Camel 1.3.0+#migrationguide],
* [Petals SE Flowable service units|petalsseflowable140:Petals-SE-Flowable 1.4.0+#migrationguide],
* [Petals SE Mapping service units|petalscomponents:Petals SE Mapping 1.2.0+#migrationguide],
* [Petals SE POJO service units|petalscomponents:Petals-SE-POJO 2.7.0+#migrationguide].