Symfony Messenger 4.3

Introduction to Symfony Messenger with a focus on the new features from the Symfony 4.3 release such as the new transports, retry strategies and handling failed messages.

Transcript

1. Symfony Messenger 4.3 Symfony User Group Köln Von Thomas Wolf, www.foto-tw.de, CC BY-SA 3.0 de, https://commons.wikimedia.org/w/index.php?curid=62082470
2. Denis Brumann @dbrumann denis.brumann@sensiolabs.de
3. Message Bus Handler
4. Message
8. framework-agnostic data object
9. Bus
12. Handler
15. framework-agnostic service reacting to a specific message
17. send receive
18. Transport
19. Sender Receiver
23. framework: messenger: transports: sync: 'sync://null' async: '%env(MESSENGER_TRANSPORT_DSN)%' routing: App\Message\RegisterUserMessage: 'async'
24. framework: messenger: transports: sync: 'sync://null' async: 'amqp://root:s3cr3t@myhost/%2f/topic' routing: App\Message\RegisterUserMessage: 'async'
26. AMQP (RabbitMQ) Doctrine Redis
30. bin/console messenger:setup-transports
31. send
32. bin/console messenger:consume receive
33. Usage: messenger:consume [options] [--] [<receivers>...] messenger:consume-messages Arguments: receivers Names of the receivers/transports to consume in order of priority [default: ["async"]] Options: -l, --limit=LIMIT Limit the number of received messages -m, --memory-limit=MEMORY-LIMIT The memory limit the worker can consume -t, --time-limit=TIME-LIMIT The time limit in seconds the worker can run --sleep=SLEEP Seconds to sleep before asking for new messages after no messages were found [default: 1] -b, --bus=BUS Name of the bus to which received messages should be dispatched (if not passed, bus is determine automatically.
34. send receive
35. Failing Messages
36. framework: messenger: ... # default configuration retry_strategy: max_retries: 3 delay: 1000 # delay for first retry multiplier: 2 # multiply delay with each try max_delay: 0 # service: null # id for custom RetryStrategy
37. UnrecoverableMessageHandlingException
38. framework: messenger: failure_transport: 'failed' transports: failed: 'doctrine://default?queue_name=failed' routing: ...
39. bin/console messenger:failed:show bin/console messenger:failed:retry bin/console messenger:failed:remove
41. Middleware
42. add_bus_name_stamp_middleware dispatch_after_current_bus send_message handle_message failed_message_processing_middleware
43. add_bus_name_stamp_middleware dispatch_after_current_bus send_message handle_message failed_message_processing_middleware your middleware your middleware your middleware
44. framework: messenger: buses: event_bus: default_middleware: 'allow_no_handlers' middleware: - 'messenger.middleware.validation'
45. ReceivedStamp HandledStamp
49. Messages Buses Handlers & Transports
50. Which messages are sent over which transport? config/packages/messenger.yaml framework : messenger : routing
51. How to limit a transport to a bus? config/packages/messenger.yaml framework : messenger : routing
52. Which Handler processes a message? Service Tag messenger.message_handler
53. Which Handler processes a message? name: 'messenger.message_handler', handles: '*', # which message(s) to handle bus: 'event_bus', # restrict handler to specific bus method: 'handleEvent', # method to be called on handler priority: 1, # prioritize handler over others from_transport: 'async', # handle only received messages
54. Which Handler processes a message?
55. Which bus is injected into a service? config/packages/services.yaml Argument Binding
56. Which bus is injected into a service? framework: messenger: default_bus: 'first_bus' buses: first_bus: middleware: - 'messenger.middleware.validation' second_bus: ...
57. Which bus is injected into a service? services: _defaults: bind: $firstBus: 'first_bus' $secondBus: 'second_bus'
58. Which bus is injected into a service?
60. Usage examples https://github.com/dbrumann/invite-registration https://github.com/dbrumann/messenger-screenshot-demo https://github.com/dbrumann/dpc2019-workshop