Changing generated code and hope it still works is slightly suboptimal, as RMB has evolved since the paste's n copy.. In particular RMB has offered new constructors for its generated client.
At this stage mod-pubsub creates a HTTP pool for each PubsubClient usage and closes the pool afterwards.. A pool that has one HTTP socket at most.
A proper solution is to use one HttpClient or WebClient per Vert.x instance (which normally is just 1 in a module). Then use that for all HTTP communications.. Then sockets can be reused between each request, thus, resulting in faster HTTP operations.
The, now, obsolete version of PubsubClient.java should be removed and RMB's generated version be used instead.
While the mod-pubsub-client artifact is included in several projects, PubsubClient is only used in mod-pubsub-client itself and mod-remote-storage.