Class: RServiceBus::Host

Inherits:
Object
  • Object
show all
Defined in:
lib/rservicebus/Host.rb

Overview

Host process for rservicebus

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Host

Returns a new instance of Host.



190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
 
# File 'lib/rservicebus/Host.rb', line 190

def initialize()
    RServiceBus.rlog "Current directory: #{Dir.pwd}"

    @config = ConfigFromEnv.new
			.loadHostSection()
			.loadContracts()
			.loadHandlerPathList()
    .loadSagaPathList()
    .loadLibs()
    .loadWorkingDirList();

    self.connectToMq()

    @endpointMapping = EndpointMapping.new.Configure( @mq.localQueueName )

    self.configureStatistics()
    .loadContracts()
    .loadLibs()
    .configureSendAtManager()
    .configureStateManager()
    .configureSagaStorage()
			.configureAppResource()
    .configureCircuitBreaker()
			.configureMonitors()
			.loadHandlers()
    .loadSagas()
    .configureCronManager()
			.configureSubscriptions()
			.sendSubscriptions()


    return self
end

Instance Attribute Details

#sagaData ⇒ Object

Returns the value of attribute sagaData.



15
16
17
 
# File 'lib/rservicebus/Host.rb', line 15

def sagaData
  @sagaData
end

Instance Method Details

#_SendAlreadyWrappedAndSerialised(serialized_object, queueName) ⇒ Object

Sends a msg across the bus

Parameters:

  • serialized_object (String) —

    serialized RServiceBus::Message

  • queueName (String) —

    endpoint to which the msg will be sent



445
446
447
448
449
450
451
452
453
 
# File 'lib/rservicebus/Host.rb', line 445

def _SendAlreadyWrappedAndSerialised( serialized_object, queueName )
    RServiceBus.rlog 'Bus._SendAlreadyWrappedAndSerialised'

    unless @config.forwardSentMessagesTo.nil? then
      @mq.send(@config.forwardSentMessagesTo, serialized_object)
    end

    @mq.send( queueName, serialized_object )
end

#_SendNeedsWrapping(msg, queueName, correlationId) ⇒ Object

Sends a msg across the bus

Parameters:

  • msg (RServiceBus::Message) —

    msg to be sent

  • queueName (String) —

    endpoint to which the msg will be sent



459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
 
# File 'lib/rservicebus/Host.rb', line 459

def _SendNeedsWrapping( msg, queueName, correlationId )
    RServiceBus.rlog 'Bus._SendNeedsWrapping'

    rMsg = RServiceBus::Message.new( msg, @mq.localQueueName, correlationId )
    if queueName.index('@').nil? then
        q = queueName
        RServiceBus.rlog "Sending, #{msg.class.name} to, queueName"
        else
        parts = queueName.split('@')
        rMsg.setRemoteQueueName( parts[0] )
        rMsg.setRemoteHostName( parts[1] )
        q = 'transport-out'
        RServiceBus.rlog "Sending, #{msg.class.name} to, #{queueName}, via #{q}"
    end

    serialized_object = YAML::dump(rMsg)
    self._SendAlreadyWrappedAndSerialised( serialized_object, q )
end

#configureAppResource ⇒ Object

Thin veneer for Configuring external resources



48
49
50
51
 
# File 'lib/rservicebus/Host.rb', line 48

def configureAppResource
    @resourceManager = ConfigureAppResource.new.getResources( ENV, self, @stateManager, @sagaStorage )
    return self;
end

#configureCircuitBreaker ⇒ Object

Thin veneer for Configuring Cron



83
84
85
86
 
# File 'lib/rservicebus/Host.rb', line 83

def configureCircuitBreaker
    @circuitBreaker = CircuitBreaker.new( self )
    return self;
end

#configureCronManager ⇒ Object

Thin veneer for Configuring Cron



143
144
145
146
 
# File 'lib/rservicebus/Host.rb', line 143

def configureCronManager
    @cronManager = CronManager.new( self, @handlerManager.getListOfMsgNames )
    return self;
end

#configureMonitors ⇒ Object

Thin veneer for Configuring external resources



91
92
93
94
 
# File 'lib/rservicebus/Host.rb', line 91

def configureMonitors
    @monitors = ConfigureMonitor.new( self, @resourceManager ).getMonitors( ENV )
    return self;
end

#configureSagaStorage ⇒ Object

Thin veneer for Configuring state



70
71
72
73
74
75
76
77
78
79
 
# File 'lib/rservicebus/Host.rb', line 70

def configureSagaStorage
    string = RServiceBus.getValue('SAGA_URI')
    if string.nil? then
        string = 'dir:///tmp'
    end

    uri = URI.parse( string )
    @sagaStorage = SagaStorage.Get( uri )
    return self;
end

#configureSendAtManager ⇒ Object

Thin veneer for Configuring SendAt



56
57
58
59
 
# File 'lib/rservicebus/Host.rb', line 56

def configureSendAtManager
    @sendAtManager = SendAtManager.new( self )
    return self;
end

#configureStateManager ⇒ Object

Thin veneer for Configuring state



63
64
65
66
 
# File 'lib/rservicebus/Host.rb', line 63

def configureStateManager
    @stateManager = StateManager.new
    return self;
end

#configureStatistics ⇒ Object

Initialise statistics monitor



184
185
186
187
188
 
# File 'lib/rservicebus/Host.rb', line 184

def configureStatistics
    @stats = StatisticManager.new( self )

    return self
end

#configureSubscriptions ⇒ Object

Load, configure and initialise Subscriptions



175
176
177
178
179
180
 
# File 'lib/rservicebus/Host.rb', line 175

def configureSubscriptions
    subscriptionStorage = ConfigureSubscriptionStorage.new.get( @config.appName, @config.subscriptionUri )
    @subscriptionManager = SubscriptionManager.new( subscriptionStorage )

    return self
end

#connectToMq ⇒ Object

Thin veneer for Configuring the Message Queue



98
99
100
101
102
 
# File 'lib/rservicebus/Host.rb', line 98

def connectToMq
    @mq = MQ.get

    return self
end

#getEndpointForMsg(msgName) ⇒ Object 



506
507
508
509
510
511
512
513
514
515
 
# File 'lib/rservicebus/Host.rb', line 506

def getEndpointForMsg( msgName )
    queueName = @endpointMapping.get( msgName )
    return queueName unless queueName.nil?

    return @mq.localQueueName if @handlerManager.canMsgBeHandledLocally(msgName)

    log 'No end point mapping found for: ' + msgName
    log '**** Check environment variable MessageEndpointMappings contains an entry named : ' + msgName
    raise 'No end point mapping found for: ' + msgName
end

#HandleMessage ⇒ Object

Send the current msg to the appropriate handlers



392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
 
# File 'lib/rservicebus/Host.rb', line 392

def HandleMessage()
    @resourceManager.Begin
    msgName = @msg.msg.class.name
    handlerList = @handlerManager.getHandlerListForMsg(msgName)


    RServiceBus.rlog 'Handler found for: ' + msgName
    begin
        @queueForMsgsToBeSentOnComplete = Array.new

        log "Started processing msg, #{msgName}"
        handlerList.each do |handler|
            begin
                log "Handler, #{handler.class.name}, Started"
                handler.Handle( @msg.msg )
                log "Handler, #{handler.class.name}, Finished"
                rescue PropertyNotSet => e
                raise PropertyNotSet.new( "Property, #{e.message}, not set for, #{handler.class.name}" )
                rescue Exception => e
                puts "E #{e.message}"
                log 'An error occurred in Handler: ' + handler.class.name
                raise e
            end
        end


        if @sagaManager.Handle( @msg ) == false && handlerList.length == 0 then
            raise NoHandlerFound.new( msgName )
        end



        @resourceManager.Commit( msgName )

        self.sendQueuedMsgs
        log "Finished processing msg, #{msgName}"

        rescue Exception => e

        @resourceManager.Rollback( msgName )
        @queueForMsgsToBeSentOnComplete = nil

        raise e
    end
end

#loadContracts ⇒ Object

Load Contracts



150
151
152
153
154
155
156
157
158
159
 
# File 'lib/rservicebus/Host.rb', line 150

def loadContracts()
    log 'Load Contracts'

    @config.contractList.each do |path|
        require path
        RServiceBus.rlog "Loaded Contract: #{path}"
    end

    return self
end

#loadHandlers ⇒ Object

Load and configure Message Handlers



116
117
118
119
120
121
122
123
124
125
126
 
# File 'lib/rservicebus/Host.rb', line 116

def loadHandlers()
    log 'Load Message Handlers'
    @handlerManager = HandlerManager.new( self, @resourceManager, @stateManager )
    @handlerLoader = HandlerLoader.new( self, @handlerManager )

    @config.handlerPathList.each do |path|
        @handlerLoader.loadHandlersFromPath(path)
    end

    return self
end

#loadLibs ⇒ Object

For each directory given, find and load all librarys



163
164
165
166
167
168
169
170
171
 
# File 'lib/rservicebus/Host.rb', line 163

def loadLibs()
    log 'Load Libs'

    @config.libList.each do |path|
        $:.unshift path
    end

    return self
end

#loadSagas ⇒ Object

Load and configure Sagas



129
130
131
132
133
134
135
136
137
138
139
 
# File 'lib/rservicebus/Host.rb', line 129

def loadSagas()
    log 'Load Sagas'
    @sagaManager = Saga_Manager.new( self, @resourceManager, @sagaStorage )
    @sagaLoader = SagaLoader.new( self, @sagaManager )

    @config.sagaPathList.each do |path|
        @sagaLoader.loadSagasFromPath(path)
    end

    return self
end

#log(string, ver = false) ⇒ Object

Provides a thin logging veneer

Parameters:

  • string (String) —

    Log entry

  • ver (Boolean) (defaults to: false) —

    Indicator for a verbose log entry



42
43
44
 
# File 'lib/rservicebus/Host.rb', line 42

def log(string, ver=false)
    RServiceBus.log( string, ver )
end

#Publish(msg) ⇒ Object

Sends an event to all subscribers across the bus

Parameters:



535
536
537
538
539
540
541
542
543
544
 
# File 'lib/rservicebus/Host.rb', line 535

def Publish( msg )
    RServiceBus.rlog 'Bus.Publish'
    @stats.incTotalPublished

    subscriptions = @subscriptionManager.get(msg.class.name)
    subscriptions.each do |subscriber|
        self.queueMsgForSendOnComplete( msg, subscriber )
    end

end

#queueMsgForSendOnComplete(msg, queueName, timestamp = nil) ⇒ Object 



488
489
490
491
492
 
# File 'lib/rservicebus/Host.rb', line 488

def queueMsgForSendOnComplete( msg, queueName, timestamp=nil )
    correlationId = @sagaData.nil? ? nil : @sagaData.correlationId
    correlationId = (!@msg.nil? && !@msg.correlationId.nil?) ? @msg.correlationId : correlationId
    @queueForMsgsToBeSentOnComplete << Hash['msg', msg, 'queueName', queueName, 'correlationId', correlationId, 'timestamp',timestamp ]
end

#Reply(msg) ⇒ Object

Sends a msg back across the bus Reply queues are specified in each msg. It works like email, where the reply address can actually be anywhere

Parameters:



499
500
501
502
503
504
 
# File 'lib/rservicebus/Host.rb', line 499

def Reply( msg )
    RServiceBus.rlog 'Reply with: ' + msg.class.name + ' To: ' + @msg.returnAddress
    @stats.incTotalReply

    self.queueMsgForSendOnComplete( msg, @msg.returnAddress )
end

#run ⇒ Object

Ignition



226
227
228
229
230
231
232
233
234
235
236
237
238
239
 
# File 'lib/rservicebus/Host.rb', line 226

def run
    log 'Starting the Host'

    log "Watching, #{@mq.localQueueName}"
    $0 = "rservicebus - #{@mq.localQueueName}"
    unless @config.forwardReceivedMessagesTo.nil? then
      log 'Forwarding all received messages to: ' + @config.forwardReceivedMessagesTo.to_s
    end
    unless @config.forwardSentMessagesTo.nil? then
      log 'Forwarding all sent messages to: ' + @config.forwardSentMessagesTo.to_s
    end

    self.StartListeningToEndpoints
end

#Send(msg, timestamp = nil) ⇒ Object

Send a msg across the bus msg destination is specified at the infrastructure level

Parameters:



522
523
524
525
526
527
528
529
530
 
# File 'lib/rservicebus/Host.rb', line 522

def Send( msg, timestamp=nil )
    RServiceBus.rlog 'Bus.Send'
    @stats.incTotalSent

    msgName = msg.class.name
    queueName = self.getEndpointForMsg( msgName )

    self.queueMsgForSendOnComplete( msg, queueName, timestamp )
end

#sendQueuedMsgs ⇒ Object 



478
479
480
481
482
483
484
485
486
 
# File 'lib/rservicebus/Host.rb', line 478

def sendQueuedMsgs
    @queueForMsgsToBeSentOnComplete.each do |row|
        if row['timestamp'].nil? then
            self._SendNeedsWrapping( row['msg'], row['queueName'], row['correlationId'] )
        else
            @sendAtManager.Add( row )
        end
    end
end

#sendSubscriptions ⇒ Object

Subscriptions are specified by adding events to the msg endpoint mapping



106
107
108
109
110
111
112
 
# File 'lib/rservicebus/Host.rb', line 106

def sendSubscriptions
    log 'Send Subscriptions'

    @endpointMapping.getSubscriptionEndpoints.each { |eventName| self.Subscribe( eventName ) }

    return self
end

#StartListeningToEndpoints ⇒ Object

Receive a msg, prep it, and handle any errors that may occur

  • Most of this should be queue independant



243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
 
# File 'lib/rservicebus/Host.rb', line 243

def StartListeningToEndpoints
log 'Waiting for messages. To exit press CTRL+C'
#            statOutputCountdown = 0
messageLoop = true
retries = @config.maxRetries

while messageLoop do
    #Popping a msg off the queue should not be in the message handler, as it affects retry
    begin
        @stats.tick

        if @circuitBreaker.Broken then
            sleep 0.5
            next
        end

        body = @mq.pop
        begin
            @stats.incTotalProcessed
            @msg = YAML::load(body)
            if @msg.msg.class.name == 'RServiceBus::Message_Subscription' then
                @subscriptionManager.add( @msg.msg.eventName, @msg.returnAddress )
                elsif @msg.msg.class.name == 'RServiceBus::Message_StatisticOutputOn' then
                @stats.output = true
                log 'Turn on Stats logging'
                elsif @msg.msg.class.name == 'RServiceBus::Message_StatisticOutputOff' then
                @stats.output = false
                log 'Turn off Stats logging'
                elsif @msg.msg.class.name == 'RServiceBus::Message_VerboseOutputOn' then
                ENV['VERBOSE'] = 'true'
                log 'Turn on Verbose logging'
                elsif @msg.msg.class.name == 'RServiceBus::Message_VerboseOutputOff' then
                ENV.delete('VERBOSE')
                log 'Turn off Verbose logging'


                else

                self.HandleMessage()

                unless @config.forwardReceivedMessagesTo.nil? then
                  self._SendAlreadyWrappedAndSerialised(body, @config.forwardReceivedMessagesTo)
                end
            end
            @mq.ack
            rescue ClassNotFoundForMsg => e
            puts "*** Class not found for msg, #{e.message}"
            puts "*** Ensure, #{e.message}, is defined in Contract.rb, most likely as 'Class #{e.message} end"

            @msg.addErrorMsg( @mq.localQueueName, e.message )
            serialized_object = YAML::dump(@msg)
            self._SendAlreadyWrappedAndSerialised(serialized_object, @config.errorQueueName)
            @mq.ack

            rescue NoHandlerFound => e
            puts "*** Handler not found for msg, #{e.message}"
            puts "*** Ensure a handler named, #{e.message}, is present in the MessageHandler directory."

            @msg.addErrorMsg( @mq.localQueueName, e.message )
            serialized_object = YAML::dump(@msg)
            self._SendAlreadyWrappedAndSerialised(serialized_object, @config.errorQueueName)
            @mq.ack

            rescue PropertyNotSet => e
            #This has been re-rasied from a rescue in the handler
            puts "*** #{e.message}"
            #"Property, #{e.message}, not set for, #{handler.class.name}"
            propertyName = e.message[10, e.message.index(',', 10)-10]
            puts "*** Ensure the environment variable, RSB_#{propertyName}, has been set at startup."

            rescue Exception => e
            sleep 0.5

            puts '*** Exception occurred'
            puts e.message
            puts e.backtrace
            puts '***'

            if retries > 0 then
                retries = retries - 1
                @mq.returnToQueue
                else

                @circuitBreaker.Failure

                @stats.incTotalErrored
                if e.class.name == 'Beanstalk::NotConnected' then
                    puts 'Lost connection to beanstalkd.'
                    puts '*** Start or Restart beanstalkd and try again.'
                    abort();
                end

                if e.class.name == 'Redis::CannotConnectError' then
                    puts 'Lost connection to redis.'
                    puts '*** Start or Restart redis and try again.'
                    abort();
                end

                errorString = e.message + '. ' + e.backtrace.join('. ')
                #                            log errorString

                @msg.addErrorMsg( @mq.localQueueName, errorString )
                serialized_object = YAML::dump(@msg)
                self._SendAlreadyWrappedAndSerialised(serialized_object, @config.errorQueueName)
                @mq.ack
                retries = @config.maxRetries
            end
        end
        rescue SystemExit, Interrupt
        puts 'Exiting on request ...'
        messageLoop = false

        rescue NoMsgToProcess => e
        #This exception is just saying there are no messages to process
        statOutputCountdown = 0
        @queueForMsgsToBeSentOnComplete = Array.new
        @monitors.each do |o|
            o.Look
        end
        self.sendQueuedMsgs
        @queueForMsgsToBeSentOnComplete = nil

        @queueForMsgsToBeSentOnComplete = Array.new
        @cronManager.Run
        self.sendQueuedMsgs
        @queueForMsgsToBeSentOnComplete = nil


        @sendAtManager.Process


        @circuitBreaker.Success

        rescue Exception => e
        if e.message == 'SIGTERM' || e.message == 'SIGINT' then
            puts 'Exiting on request ...'
            messageLoop = false
            else
            puts '*** This is really unexpected.'
            messageLoop = false
            puts 'Message: ' + e.message
            puts e.backtrace
        end
    end
end
end

#Subscribe(eventName) ⇒ Object

Sends a subscription request across the Bus

Parameters:

  • eventName (String) —

    event to be subscribes to



549
550
551
552
553
554
555
556
 
# File 'lib/rservicebus/Host.rb', line 549

def Subscribe( eventName )
    RServiceBus.rlog 'Bus.Subscribe: ' + eventName

    queueName = self.getEndpointForMsg( eventName )
    subscription = Message_Subscription.new( eventName )

    self._SendNeedsWrapping( subscription, queueName, nil )
end