NAME

       doc_decisions_pubsub_md - Pub/Sub Communication

   Issue
       To develop a Web UI, we need to be able to remotely configure Elektra via a network
       socket.

       The idea is to use a Pub/Sub concept to synchronize actions which describe changes in the
       Elektra state.

   Constraints
       • We need to be able to synchronize all changes in Elektra with the Web UI.

       • This needs to be done via a network socket due to limitations of the Web.

       • That means we need to run an Elektra daemon (elektrad) to be able to connect to Elektra
         at any time.

   Assumptions
   Considered Alternatives
       • ZeroMQ: small and popular library for pub/sub

       • nanomsg: from the same author as ZeroMQ, even smaller -
         http://nanomsg.org/documentation-zeromq.html

       • redis: requires a running redis server

       • kafka: seems too big for Elektra

   Decision
       Use ZeroMQ with JSMQ.

   Argument
       nanomsg sounds interesting, but isn't as popular as ZeroMQ, which is why there are no
       browser JS bindings available (only Node.js, which cannot be easily used for the Web UI).

   Implications
   Related decisions
   Notes