Method for bridging publish/subscribe brokers for guaranteed low-latency delivery

• US 10,637,960 B2
• Filed: 10/21/2016
• Issued: 04/28/2020
• Est. Priority Date: 10/21/2016
• Status: Active Grant

• Current Assignee: infiswift Technologies, Inc.
• Original Assignee: infiswift Technologies, Inc.
• Inventors: Srinivasan, Jayendran, Selvaraj, Venkatesa Prasannaa, Thulasingam, Saravanan
• Primary Examiner(s): Whipple, Brian
• Assistant Examiner(s): Fan, John
• Application Number:
  US15/331,680
• Publication Number:
  US 20180115616A1
• Time in Patent Office: 1,285 Days
• Field of Search: 709223
• CPC Class Codes: H04L 67/141 Setup of application sessions admission control or resource allocation in data switching networks H04L47/70
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching
• CPC Class Codes: H04L 67/60 Scheduling or organising the servicing of application requests, e.g. requests for application data transmissions using the analysis and optimisation of the required network resources admission control or resource allocation H04L47/70

Abstract

Methods for bridging computers functioning as Publish/Subscribe brokers are provided to build a distributed cluster for scalability by enabling publishers to connect to one broker and subscribers to that publisher to connect to a different broker. In one aspect, a method includes listening to an internal bridge port on one broker for receiving bridge connections from other brokers in the cluster, and in parallel, connecting to the internal bridge ports of each of the other brokers in the cluster, waiting for all such incoming and outgoing bridge connections to be completed, and then opening up the external port for serving actual clients. The method also includes creating separate bridges for each direction of traffic to make the broker code completely symmetric and also supporting the creation of an arbitrary number of bridge connections between each pair of brokers for each direction to reduce latency.

Claims

1. In a publish-subscribe cluster comprising at least a first broker and a second broker, wherein at least a subscriber receives at least a message for a given topic published by at least a publisher connected to one of said first broker and second broker, a computer-implemented method comprising:

at least said first broker accepting one or more inbound network connections from said second broker for the purpose of acting as a first bridge to send messages intended for one or more subscribers that are connected to said second broker;

at least said first broker initiating one or more outbound network connections to said second broker for the purpose of acting as a second bridge to receive messages intended for one or more subscribers that are connected to said first broker;

sending one or more messages on said first bridge intended for the one or more subscribers that are connected to atleast a subscriber on said second broker;

receiving one or more messages on said second bridge intended for one or more subscribers that are connected to the first broker.

2. The method of claim 1 further comprising said first broker having access to information about a state of said second broker by validating that said second broker is listed as active in an active broker table.

3. The method of claim 2 further comprising using said active broker table to determine to which brokers to initiate said one or more outbound network connections.

4. The method of claim 2 further comprising using said active broker table to determine from which brokers to expect said one or more inbound network connections.

5. The method of claim 2 further comprising using said active broker table to validate a source address of said one or more inbound network connections before accepting them.

6. The method of claim 2 further comprising waiting for all of said one or more inbound and outbound network connections from brokers to be established before allowing publishers and subscribers to connect to brokers upon starting up one of said brokers.

7. The method of claim 1 wherein a first port on said first broker is used for accepting the one or more inbound network connections from at least an additional broker, and a second external port on said first broker is used for accepting connections from at least one publisher.

8. The method of claim 1 further comprising monitoring a status of one or more established outbound network connections from said first broker to at least an additional broker;

and reinitiating at least an outbound network connection using one or more same connections in if said one or more established outbound network connections have previously been terminated.

9. The method of claim 1 further comprising monitoring a status of one or more accepted inbound network connections to said first broker from at least an additional broker;

and storing pending messages destined for said additional broker during periods when said one or more accepted inbound network connections from said additional broker is broken, and transmitting said pending messages in a correct order when said one or more accepted inbound network connections have been restored.

10. A system for reducing latency between and among bridging brokers of a publish-subscribe cluster using a MQTT protocol comprised of at least a plurality of brokers within a single cluster, the system in each broker comprising:

at least memory comprising instructions;

at least a processor configured to execute instructions to;

accept on at least a first broker, one or more inbound network connections directly from at least a second broker from one or more additional brokers, each of said one or more inbound network connections acting as at least a first direct one-way bridge that receives one or more first messages intended for one or more first subscribers that are connected to said first broker, where said first direct one-way bridge is used only to receive said one or more first messages directly from said second broker without routing the one or more first messages through any intermediate brokers;

initiating on said first broker, one or more outbound network connections directly to said second broker, each of said one or more outbound network connections acting as a second direct one-way bridge that sends one or more second messages intended for one or more second subscribers that are connected to said second broker, where said second direct one-way bridge is used only to send said one or more second messages from said first broker to said second broker without routing the one or more second messages through any intermediate brokers;

receiving at said first broker, one or more messages on said first direct one-way bridge directly from said second broker without routing the one or more messages through any intermediate brokers, the one or more first messages intended for at least the one or more first subscribers a connected to said first broker wherein said one or more first messages are received directly from said second broker without routing the one or more first messages through any intermediate brokers; and

sending one or more second messages on said second direct one-way bridge directly from said first broker to said second broker without routing the one or more second messages through any intermediate brokers, the one or more second messages intended for at least the one or more second subscribers connected to said second broker wherein said one or more second messages are sent directly from said first broker to said second broker without routing the one or more second messages through any intermediate brokers.

11. The system of claim 10, wherein at least a processor on said first broker is further configured to execute instructions to access information about a state of said one or more additional brokers connected to said first broker, including validating that said second broker is listed as active in an active broker table;

use said active broker table to determine to which of said additional brokers outbound network connections should be initiated;

use said active broker table to determine which of said additional brokers to expect the one or more inbound network connections from; and

use said active broker table to validate a source address of said one or more inbound network connections before accepting them.

12. The system of claim 10, wherein said processor is further configured to execute instructions to wait for all inbound and outbound network connections to said first broker to be established before allowing publishers and subscribers to connect to said first broker upon starting up of said first broker.

13. The system of claim 10, wherein said one or more inbound and outbound network connections use a first port on said first broker to connect said first broker with at least an additional broker, and a second port for accepting connections from at least one publisher.

14. The system of claim 10, wherein said processor in said first broker is further configured to:

execute instructions to monitor a status of said one or more outbound network connections from said first broker to said second broker

reinitiating at least the one or more outbound network connections if said one or more outbound network connections have previously been terminated;

monitoring a status of one or more accepted inbound network connections to said first broker from said second broker; and

storing pending messages destined for said first broker during periods when said one or more inbound network connections are broken, and transmitting said pending messages in a correct order when said one or more inbound network connections have been restored.

15. The system of claim 10, wherein said processor of said first broker is further configured to execute instructions to monitor a status of one or more accepted inbound network connections from at least an additional broker;

and to store pending messages destined for said additional broker during a period when said one or more accepted inbound network connections from said one or more additional brokers are broken.

16. A non-transitory machine-readable storage medium comprising machine-readable instructions for reducing latency by causing a processor to execute a method for bridging brokers using a MQTT protocol, the method comprising:

accepting on a first broker one or more inbound network connections directly from at least a second broker from one or more additional brokers for a purpose of establishing a first direct one-way bridge to receive one or more first messages intended for one or more first subscribers that are connected to said first broker, where said first direct one-way bridge is used only to receive messages directly from said second broker without routing the one or more first messages through any intermediate brokers;

initiating one or more outbound network connections directly from said first broker to said second broker for a purpose of acting as a second direct one-way bridge to receive one or more second messages intended for one or more of second subscribers directly connected to said second broker, where said second direct one-way bridge is used only to send messages directly from said first broker to said second broker directly without routing the one or more second messages through any intermediate brokers;

receiving the one or more first messages on said first direct one-way bridge intended for the one or more first subscribers connected said first broker without routing the one or more first messages through any intermediate brokers;

send the one or more second messages on said second direct one-way bridge intended for the one or more second subscribers connected to said first second broker wherein said one or more second messages are sent directly from said first broker to said second broker without routing the one or more second messages through any intermediate brokers.

17. The non-transitory machine-readable storage medium of claim 16 further comprising:

having access to information about a state of said additional brokers connected to said first broker;

using said information to determine which brokers to initiate the one or more outbound network connections to, including validating that said one or more additional brokers are listed as active in an active broker table;

using said information to determine to which of said one or more additional brokers the one or more outbound network connections should be initiated; and

using said information to validate a source address of said one or more inbound network connections before accepting them.

18. The non-transitory machine-readable storage medium of claim 16 further comprising, upon starting said first broker, waiting for the one or more inbound and outbound network connections to be established before allowing publishers and subscribers to connect to said first broker.

19. The non-transitory machine-readable storage medium of claim 16 wherein said one or more inbound and outbound network connections use a first port on said first broker to connect said first broker with at least an additional broker, and a second port for accepting connections from at least one publisher.

20. The non-transitory machine-readable storage medium of claim 16 further comprising monitoring the a status of one or more established outbound network connections to one or more remote brokers;

and reinitiating the one or more established outbound network connections.

21. The non-transitory machine-readable storage medium of claim 16 wherein said first broker monitors a the status of one or more accepted inbound network connections from said one or more additional brokers;

and stores pending messages destined for said one or more additional brokers when said one or more inbound network connections to said one or more additional brokers are broken, and transmitting said pending messages in a correct order when said one or more inbound network connections have been restored.