The migration guide can be found in our documentation <https://cloud.google.com/appengine/docs/flexible/java/migrating>. The main difference is that instances are now Compute Engine VMs <https://cloud.google.com/compute/>, which means the old App Engine API <https://cloud.google.com/appengine/docs/standard/java/javadoc/>is no longer accessible (since it only works from the App Engine Standard environment). Migrating to Flex simply means migrating your code to using the new Google Cloud Client Libraries <https://cloud.google.com/apis/docs/cloud-client-libraries>.
All of your Datastore data will still be accessible if you deploy a Flexible version of your code to the same project. But you will need to use the new Objectify version 6 <https://github.com/objectify/objectify/wiki/FrequentlyAskedQuestions#can-i-use-objectify-from-a-gae-flexible-runtime> which uses the new Client Libraries by following their code migration guide <https://github.com/objectify/objectify/wiki/UpgradeVersion5ToVersion6>. The Firebase Libraries <https://firebase.google.com/docs/libraries/>are also not App Engine specific (meaning they are accessible from outside of App Engine) and can be used from anywhere (e.g Flex, Standard <https://cloud.google.com/solutions/using-firebase-real-time-events-app-engine>, etc). For a quick example on how to use Firebase from the App Engine Flexible environment you can view their quickstart tutorial <https://cloud.google.com/solutions/mobile/mobile-firebase-app-engine-flexible> . - Note that Google Groups if for general product discussions and not for technical support. For any further technical support in migrating your code it is recommended to post your detailed questions <https://stackoverflow.com/help/how-to-ask> to Stack Overflow <https://cloud.google.com/support/docs/stackexchange> using the supported cloud tags. -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-appengine+unsubscr...@googlegroups.com. To post to this group, send email to google-appengine@googlegroups.com. Visit this group at https://groups.google.com/group/google-appengine. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/1a9ecfcf-f759-452e-881a-d879a90d79d8%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
