README.adoc

JBUG Brno - November 2017: Saga over REST for microservices

The talk presents Narayana LRA for usage in microservice architecture.
It shows difference of Saga concept to distributed transactions (shown in the helloworld demo where WildFly servers communicates with each other under one distributed transaction)
Describe how the saga works
Demoing the LRA based of the https://github.com/redhat-helloworld-msa/helloworld-msa
Slides by reveal.js, the presentation could be read in adoc format at saga-jbug.adoc.

First shows distributed transactions over WildFly 11 ejb remote calls. Available at jta distributed wfly demo. It requires docker being available at the system and then the setup.sh should install the containers and deploy what’s needed. You can then use curl to query the servlet to start the transaction. You will probably need to open some database viewer to show the audience the content of the table in case of distributed transaction succeeded or if fails (the file TransactionEJB.java then could be 'update' for throwning RuntimeException and cause the transaction being rolled-back as whole (no changes in database).
Second expects to be run and shown on OpenShift and settings is described at https://developer.jboss.org/wiki/MSAQuickstartsWithLRAREST-ATOnMinishift . You will need a OpenShift started probably locally (check Minishift) and run the ansible recipe from https://github.com/ochaloup/helloworld-msa/tree/lra