outline of loadbalance transport

gistfile1.js

module.exports = function( options ) {
  var seneca = this
  var plugin = 'loadbalance-transport'

  var so = seneca.options()

  options = seneca.util.deepextend(
    {
      loadbalance: {
         workers: [ ... ]
      },
    },
    so.transport,
    options)
  

  var tu = seneca.export('transport/utils')


  seneca.add({role:'transport',hook:'listen',type:'loadbalance'}, hook_listen_loadbalance)
  seneca.add({role:'transport',hook:'client',type:'loadbalance'}, hook_client_loadbalance)




  function hook_listen_loadbalance( args, done ) {
    done( seneca.fail("cant-loadbalance-listen") )
  }


  function hook_client_redis( args, clientdone ) {
    var seneca         = this
    var type           = args.type
    var client_options = seneca.util.clean(_.extend({},options[type],args))

    tu.make_client( make_send, client_options, clientdone )

    // set up the workers - this is pseudo-ish code 
    var senecamap = {}
    workers.forEach(function( spec ){
      // load the underlying transport
      senecamap[workerid] = require('seneca')().use( spec.name?, spec.options?)

      ping( senecamap[workerid] )
    })
     

    function ping( seneca ) {
      seneca.act( 'role:transport,cmd:ping', function(err,out){
        if( timeout err ) {
          // KILL the worker and try to reload
        }
        
        setTimeout(ping)
      } )
    }


    function make_send( spec, topic, send_done ) {
      send_done( null, function( args, done ) {

        var seneca = next round robin entry from senecamap
        seneca.act( args, done )
      })
    }

  // in this case, close gobally, not per topic, as there is no pre topic connection here
      seneca.add('role:seneca,cmd:close',function( close_args, done ) {
        var closer = this

        forEach senecamap: seneca.close()

        closer.prior(close_args,done)
      })
  }  


  function handle_events( redisclient ) {
    // Die if you can't connect initially
    redisclient.on('ready', function() {
      redisclient.on('error', function(err){
        seneca.log.error('transport','redis',err)
      })
    })
  }

  return {
    name: plugin,
  }
}