Methods and Systems For Managing Shared State Within A Distributed System With Varying Consistency And Consenus Semantics

• US 20070260689A1
• Filed: 05/04/2006
• Published: 11/08/2007
• Est. Priority Date: 05/04/2006
• Status: Active Grant

• Current Assignee: GOTO Group Incorporated (LogMeIn, Inc.)
• Original Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Inventors: Chalmers, Robert, Bryan, Todd
• Granted Patent: US 8,769,019 B2
• Time in Patent Office: Days
• US Class Current: 709/205
• CPC Class Codes: G06Q 10/10 Office automation; Time management
• CPC Class Codes: H04L 12/1822 Conducting the conference, e.g. admission, detection, selection or grouping of participants, correlating users to one or more conference sessions, prioritising transmission
• CPC Class Codes: H04L 12/1863 comprising mechanisms for improved reliability, e.g. status reports arrangements for detecting or preventing errors by carrying supervisory signal the return channel H04L1/16

Abstract

Methods and systems for managing shared state within a distributed system with varying consistency and consensus semantics are described. In one configuration, a computing device receives a first plurality of objects representing the state of a first item and a second plurality of objects representing the state of a second item. The computing device generates a composed view of the state of each of the first item and the second item. The resulting composed views are transmitted using a reliable multicast protocol.

Claims

1. A method of generating a composed view of the state of a plurality of items in a distributed computing system having a plurality of computing devices, the method comprising:

(a) receiving a first plurality of objects having the same number of fields, each of the first plurality representing a state of a first item, each field of the first plurality of objects storing information that defines the state of the first item;

(b) operating, by a first composer module, on the first plurality of objects to generate a first composed view object of the state of the first item, the first composed view object having the same number of fields as each of the first plurality of objects;

(c) receiving a second plurality of objects having the same number of fields, each of the second plurality representing a state of a second item, each field of the second plurality of objects storing information that defines the state of the second item;

(d) operating, by a second composer module, on the second plurality of objects to generate a second composed view object of the state of the second item, the second composed view object having the same number of fields as each of the second plurality of objects; and

(e) transmitting the first composed view object and the second composed view object using a reliable multicast protocol to at least some of the plurality of computing devices of the distributed computing system.

2. The method of claim 1 wherein at least one of step (a) and (c) comprises receiving a plurality of objects having the same number fields, each field storing information that defines the state of the object, the information stored in the field comprising one of the following data types:

static state, monotonically increasing state, versioned cyclic state transition, a monotonic set, and non-cyclic state transitions.

3. The method of claim 2 wherein the data type of the at least one of the plurality of fields is different from at least some of the others of the plurality of fields

4. The method of claim 1 wherein operating by one of the first composer and the second composer comprises operating on the plurality of objects to generate a consensus composed view.

5. The method of claim 1 wherein operating by one of the first composer and the second composer comprises operating on the plurality of objects to generate a consistency composed view.

6. The method of claim 1 wherein operating by one of the first composer and the second composer comprises performing an intersection operation on at least one of the plurality of fields of the plurality of objects.

7. The method of claim 1 wherein operating by one of the first composer and the second composer comprises performing an union operation on at least one of the plurality of fields of the plurality of objects.

8. The method of claim 1 wherein operating by one of the first composer and the second composer comprises performing an a maximum value determination on at least one of the plurality of fields of the plurality of objects.

9. The method of claim 1 wherein operating by one of the first composer and the second composer comprises performing an minimum value determination on at least one of the plurality of fields of the plurality of objects.

10. The method of claim 1 wherein operating by one of the first composer and the second composer comprises performing a first operation on at least one of the plurality of fields of the plurality of objects and performing a second operation on another one of the plurality of field of the plurality of objects.

11. A system for generating a composed view of the state of a plurality of items in a distributed computing system having a plurality of computing devices, the system comprising:

a receiver in communication with network using a reliable multi-cast protocol receiving a first plurality of objects having the same number of fields, each of the first plurality representing a state of a first item, each field of the first plurality of objects storing information that defines the state of the first item and a a second plurality of objects having the same number of fields, each of the second plurality representing a state of a second item, each field of the second plurality of objects storing information that defines the state of the second item;

a first composer in communication with the receiver, the first composer operating on the first plurality of objects to generate a first composed view object of the state of the first item, the first composed view object having the same number of fields as each of the first plurality of objects;

a second composer in communication with the receiver, the second composer operating on the second plurality of objects to generate a second composed view object of the state of the second item, the second composed view object having the same number of fields as each of the second plurality of objects; and

a transmitter in communication with the composer and a network using a reliable multi-cast protocol, the transmitter transmitting, using the reliable multi-cast protocol, the first composed view object and the second composed view object to at least some of the plurality of computing devices of the distributed computing system.

12. The system of claim 11 wherein the information stored in the field comprises one of the following data types:

static state, monotonically increasing state, versioned cyclic state transition, a monotonic set, and non-cyclic state transitions.

13. The system of claim 12 wherein the data type of the at least one of the plurality of fields is different from at least some of the others of the plurality of fields

14. The system of claim 11 wherein one of the first composer and the second composer operates on the plurality of objects and generates a consensus composed view.

15. The system of claim 11 wherein one of the first composer and the second composer operates on the plurality of objects and generates a consistency composed view.

16. The system of claim 11 wherein one of the first composer and the second composer performs an intersection operation on at least one of the plurality of fields of the plurality of objects.

17. The system of claim 11 wherein one of the first composer and the second composer performs an union operation on at least one of the plurality of fields of the plurality of objects.