EVENT HANDLING IN DISTRIBUTED EVENT HANDLING SYSTEMS

• US 20190012218A1
• Filed: 07/10/2017
• Published: 01/10/2019
• Est. Priority Date: 07/10/2017
• Status: Active Grant

• Current Assignee: Nokia Solutions and Networks OY (Nokia Corporation)
• Original Assignee: Nokia Solutions and Networks OY (Nokia Corporation)
• Inventors: Rimac, Ivica, Akkus, Istemi Ekin, Chen, Ruichuan, Stein, Manuel, Hilt, Volker
• Granted Patent: US 11,385,944 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 2209/548 Queue
• CPC Class Codes: G06F 9/4881 Scheduling strategies for dispatcher, e.g. round robin, multi-level priority queues
• CPC Class Codes: G06F 9/542 Event management; Broadcasting; Multicasting; Notifications
• CPC Class Codes: G06F 9/546 Message passing systems or structures, e.g. queues

Abstract

The present disclosure generally discloses an event handling capability configured to support handling of events. The event handling capability may be configured to support handling of events in a distributed event handling system, which may use distributed queuing of events, distributed processing of events, and so forth. The distributed event handling system may be serverless cloud system or other type of distributed event handling system. The event handling capability may be configured to support handling of events in a distributed event handling system based on use of a message bus for queuing of events and based on use of hosts for queuing and processing of events.

Claims

1. An apparatus configured to support handling of events by a message bus of an event handling system, the apparatus comprising:

a processor and a memory communicatively connected to the processor, the processor configured to;

maintain, by the message bus for an event type, a respective set of event queues for the event type, wherein the event queues for the event type are associated with respective ones of a set of hosts subscribed to the message bus for the event type;

receive, by the message bus for the event type, an event of the event type that is published to the message bus;

store, by the message bus, the event of the event type in one of the event queues for the event type based on respective sets of queue status information associated with the respective event queues; and

send, by the message bus, the event of the event type toward one of the hosts subscribed to the message bus for the event type based on a request from the one of the hosts subscribed to the message bus for the event type.

2. The apparatus of claim 1, wherein the processor is configured to:

instantiate the respective event queues for the event type based on respective requests by the respective hosts to subscribe to the message bus for the event type.

3. The apparatus of claim 1, wherein, for at least one of the event queues, the respective set of queue status information comprises at least one of a queue length of the respective event queue, an event arrival rate of the respective event queue, or an event departure rate of the respective event queue.

4. The apparatus of claim 1, wherein the processor is configured to:

compute, for each of the event queues based on the respective sets of queue status information associated with the respective event queues, a respective queue score for the respective event queue.

5. The apparatus of claim 4, wherein the respective queue scores for the respective event queues are configured to enable selection of a longer one of the event queues over a shorter one of the event queues, for storing events of the event type, based on an indication that a length of the longer one of the event queues and a length of the shorter one of the event queues are changing at different rates.

6. The apparatus of claim 4, wherein the respective queue score of the respective event queue is based on an exponentially weighted moving average of a queue length of the respective event queue and an exponentially weighted moving average of a departure rate of the respective event queue.

7. The apparatus of claim 1, wherein the processor is configured to:

terminate the respective event queues for the event type based on respective requests by the respective hosts to unsubscribe from the message bus for the event type.

8. The apparatus of claim 1, wherein the processor is configured to:

send, toward a function manager configured to support scaling of hosts within the event handling system, the respective queue status information of the respective event queues.

9. The apparatus of claim 1, wherein the processor is configured to:

send, toward a function manager configured to support scaling of hosts within the event handling system, per-host queue status information of the host determined based on the respective queue status information of the respective event queue associated with the host and based on queue status information of a second event queue associated with the host for a second event type.

10. A method for handling of events by a message bus of an event handling system, the method comprising:

maintaining, by the message bus for an event type, a respective set of event queues for the event type, wherein the event queues for the event type are associated with respective ones of a set of hosts subscribed to the message bus for the event type;

receiving, by the message bus for the event type, an event of the event type that is published to the message bus;

storing, by the message bus, the event of the event type in one of the event queues for the event type based on respective sets of queue status information associated with the respective event queues; and

sending, by the message bus, the event of the event type toward one of the hosts subscribed to the message bus for the event type based on a request from the one of the hosts subscribed to the message bus for the event type.

11. An apparatus, comprising:

a processor and a memory communicatively connected to the processor, the processor and the memory configured to support a message bus of an event handling system, the message bus comprising;

a set of event queues for an event type supported by the event handling system, wherein the event queues for the event type are configured to store events for respective ones of a set of hosts subscribed to the message bus for the event type;

a queue monitoring element configured to monitor the event queues and to determine, for each of the event queues, respective queue status information associated with the respective event queue; and

an event dispatch element configured to receive an event of the event type that is published to the message bus and to dispatch the event of the event type to one of the event queues for the event type based on the respective queue status information associated with the respective event queues;

wherein the message bus is configured to send the event of the event type toward one of the hosts subscribed to the message bus for the event type based on a request from the one of the hosts subscribed to the message bus for the event type.

12. An apparatus configured to support handling of events by a host of an event handling system, the apparatus comprising:

a processor and a memory communicatively connected to the processor, the processor configured to;

subscribe, by the host, to a first event queue of a message bus, the first event queue of the message bus configured to store events of a first event type to be processed by a first event processing function of the host;

subscribe, by the host, to a second event queue of the message bus, the second event queue configured to store events of a second event type to be processed by a second event processing function of the host;

maintain, by the host, a local buffer configured to store events received from the first event queue of the message bus and events received from the second event queue of the message bus; and

retrieve, by the host based on a local queuing policy of the host and a local event retrieval condition detected at the host, a retrieved event comprising a first event from the first event queue of the message bus or a second event from the second event queue of the message bus.

13. The apparatus of claim 12, wherein the processor is configured to subscribe to the first event queue of the message bus based on a determination that the host supports the first event processing function.

14. The apparatus of claim 12, wherein the processor is configured to subscribe to the second event queue of the message bus based on a determination that the host supports the second event processing function.

15. The apparatus of claim 12, wherein the processor is configured receive scaling requests from a function manager, wherein the processor is configured to subscribe to the first event queue of the message bus based on a first request from the function manager and to subscribe to the second event queue of the message bus based on a second request from the function manager.

16. The apparatus of claim 12, wherein the local buffer of the host comprises a first host event queue configured to store events received from the first event queue of the message bus and a second host event queue configured to store events received from the second event queue of the message bus.

17. The apparatus of claim 12, wherein the local buffer of the host comprises a first-in-first-out buffer configured to store events received from the first event queue of the message bus and events received from the second event queue of the message bus.

18. The apparatus of claim 12, wherein the processor is configured to:

select, by the host from the local buffer configured to store events received from the first event queue of the message bus and events received from the second event queue of the message bus based on a local event selection condition detected at the host, a selected event; and

process the selected event.

19. The apparatus of claim 18, wherein the selected event is an event of the first event type, wherein the selected event is processed by the host using the first event processing function of the host.

20. The apparatus of claim 18, wherein the selected event is an event of the second event type, wherein the selected event is processed by the host using the second event processing function of the host.

21. The apparatus of claim 12, wherein the processor is configured to:

detect a request for the host to stop handling events of the first event type;

unsubscribe from the first event queue of the message bus based on the request for the host to stop handling events of the first event type;

process, by the host using the first event processing function of the host, any events of the local buffer of the host of the first event type; and

initiate removal of the first event processing function from the host.

22. The apparatus of claim 12, wherein the processor is configured to:

detect a request for the host to stop handling events of the second event type;

unsubscribe from the second event queue of the message bus based on the request for the host to stop handling events of the second event type;

process, by the host using the second event processing function of the host, any events of the local buffer of the host of the second event type; and

initiate removal of the second event processing function from the host.

23. A method to support handling of events by a host of an event handling system, the method comprising:

subscribing, by the host, to a first event queue of a message bus, the first event queue of the message bus configured to store events of a first event type to be processed by a first event processing function of the host;

subscribing, by the host, to a second event queue of the message bus, the second event queue configured to store events of a second event type to be processed by a second event processing function of the host;

maintaining, by the host, a local buffer configured to store events received from the first event queue of the message bus and events received from the second event queue of the message bus; and

retrieving, by the host based on a local queuing policy of the host and a local event retrieval condition detected at the host, a retrieved event comprising a first event from the first event queue of the message bus or a second event from the second event queue of the message bus.