To manage the LRA, we need a coordinator that manages the saga processing. We have chosen a Narayana implementation, as a standalone service, to implement this concept.

You can download it at http://narayana.io/downloads/index.html; for our implementation, we will use version 5.9.0.

After downloading it, you will need to unzip it to a directory of your choice, which, from now on, will be defined as $NARAYANA_HOME.

Finally, you should run the Narayana LRA coordinator by using the following command:

$ java -jar $NARAYANA_HOME/rts/lra/lra-coordinator-swarm.jar   -Dswarm.http.port=8580 

We have now launched the coordinator as a standalone service that listens on port 8580 to avoid port conflicts with the services that we implemented in Chapter 3, Cloud Native Applications, and with the new services that we will build in the following sections.

In the service's log, at the end, you should notice the following messages that confirm that the Narayana coordinator is up and running:

2018-08-23   16:43:52,134 INFO  [io.narayana.lra] (ServerService Thread Pool -- 6)   LRAClient assuming the LRA coordinator and recovery coordinator are on the   same endpoing
   2018-08-23 16:43:52,170 INFO  [org.wildfly.extension.undertow] (ServerService   Thread Pool -- 6) WFLYUT0021: Registered web context: /
   2018-08-23 16:43:52,199 INFO  [org.jboss.as.server] (main) WFLYSRV0010:   Deployed "lra-coordinator.war" (runtime-name : "lra-coordinator.war")
   2018-08-23 16:43:52,200 INFO  [org.wildfly.swarm] (main) WFSWARM99999:   WildFly Swarm is Ready