Data communication coordination with sequence numbers

• US 8,316,129 B2
• Filed: 07/15/2005
• Issued: 11/20/2012
• Est. Priority Date: 05/25/2005
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Kruse, David, Mohamed, Ahmed, Raman, Balan Sethu
• Primary Examiner(s): Salad, Abdullahi
• Assistant Examiner(s): Keehn, Richard G
• Application Number:
  US11/182,989
• Publication Number:
  US 20060271692A1
• Time in Patent Office: 2,685 Days
• Field of Search: 709/226
• US Class Current: 709/226
• CPC Class Codes: G06F 16/182 Distributed file systems
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 63/10 for controlling access to devices or network resources
• CPC Class Codes: H04L 63/123 received data contents, e.g. message integrity
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 67/147 Signalling methods or messages providing extensions to protocols defined by standardisation
• CPC Class Codes: H04L 69/02 Protocol performance
• CPC Class Codes: H04L 69/14 Multichannel or multilink protocols
• CPC Class Codes: H04L 69/18 Multiprotocol handlers, e.g. single devices capable of handling multiple protocols
• CPC Class Codes: H04L 69/24 Negotiation of communication capabilities
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

Described are sequence numbers for client-server communication, to control a client'"'"'s use of server resources. A server grants the client credits, and the client consumes a credit for sending each command to the server. Each credit corresponds to a sequence number, with the set of sequence numbers forming a valid command window. The server enforces that for each received command, the command includes a sequence number that is within the valid command window and that the sequence number has not been used with another command. The server may also maintain a maximum window size, such that clients with credits cannot send a command with a sequence number that beyond a maximum sequence number. When incorporated into a data communication protocol, quality of service, combating denial of service, detection of message loss, division of server resources, secure message signing, and other numerous benefits result.

Claims

1. In a network computing environment having a client and server, a method comprising:

establishing, by a server computing device, a session for receiving file system commands from a client;

establishing, by the server computing device, a valid command window comprising at least one sequence number, wherein the valid command window is adjusted to include an additional unused sequence number in response to the client being granted an additional credit, wherein the additional credit enables the client to consume server resources using the file system commands;

receiving, at the server computing device, a file system command that consumes at least one server resource, the file system command including an associated sequence number;

determining whether the associated sequence number is within the valid command window;

determining whether the associated sequence number has not been previously included in another file system command;

allowing the file system command upon determining the associated sequence number is within the valid command window and has not been previously included in another file system command sent during the session; and

granting to the client a first additional credit and adjusting the valid command window to include a first additional unused sequence number.

2. The method of claim 1 further comprising, allowing the command upon determining that the associated sequence number is not beyond a maximum sequence number.

3. The method of claim 1 further comprising, in response to the received command, granting to the client a second additional credit and adjusting the valid command window to include a second additional unused sequence number.

4. The method of claim 1 wherein, allowing the file system command consumes one credit granted to the client.

5. The method of claim 1 further comprising:

granting the client one or more blocking operation credits; and

allowing a blocking operation to be performed by the server in response to receiving a blocking command sent from the client wherein the blocking command has not exceeded a maximum number of blocking operation credits.

6. The method of claim 5 further comprising:

returning data indicating the blocking operation'"'"'s progress; and

returning an identifier for the blocking operation.

7. The method of claim 6 further comprising, granting to the client an additional credit and adjusting the valid command window in response to receiving the blocking operation command.

8. The method of claim 1 further comprising, processing a received request for an additional credit from the client.

9. The method of claim 1 further comprising, revoking at least one credit previously granted to the client.

10. At least one computer-storage medium not consisting of a propagated data signal having computer executable instructions, which when executed perform steps, comprising:

establishing a session for receiving file system commands from a client;

establishing a valid command window comprising at least one sequence number, wherein the valid command window is adjusted to include an additional unused sequence number in response to the client being granted an additional credit, wherein the additional credit enables the client to consume server resources using the file system commands;

receiving a file system command to consume at least one server resource, the file system command including an associated sequence number;

determining whether the associated sequence number is within the valid command window;

determining whether the associated sequence number has not been included in another file system command;

allowing the file system command upon determining the associated sequence number is within the valid command window and has not been included in another file system command during the session, otherwise denying the file system command; and

granting to the client a first additional credit and adjusting the valid command window to include a first additional unused sequence number.

11. The computer-storage medium of claim 10 wherein the step of granting to the client a first additional credit is performed upon determining not to revoke the credits previously granted to the client.

12. The computer-storage medium of claim 10 wherein the step of granting the client a first additional credit is performed when the sequence number in the valid command window does not exceed a maximum window size.

13. The computer-storage medium of claim 10 comprising instructions which when executed perform the step of revoking at least one credit previously granted to the client.

14. The computer-storage medium of claim 10 having further computer executable instructions, comprising:

granting to the client one or more blocking operation credits; and

allowing a blocking operation to be performed by the server in response to receiving a blocking command sent from the client, wherein the blocking command has not exceeded a maximum number of blocking operation credits.

15. In a network computing environment having a client and server, a server-side system comprising:

at least one processor; and

at least one memory with computer executable instructions that when executed by the at least one processor provide;

a server mechanism that establishes a session for receiving file system commands from a client and limits use of server resources by controlling a number of credits granted to the client, the credit enabling the client to consume one or more server resources using a file system command, the mechanism including;

a valid command window, containing unique numbers, one for each credit granted to the client;

an enforcement mechanism that allows the client to consume the one or more server resources for the file system command, provided the unique number associated with the file system command is within the valid command window and has not been included in another file system command during the session; and

an allocation mechanism that controls credits granted to the client and the unique numbers within the valid command window, wherein the valid command window is adjusted to include an additional unique number in response to the client being granted an additional credit.

16. The system of claim 15 wherein the enforcement mechanism includes a server message block protocol driver.

17. The system of claim 15 wherein the server mechanism is configured to revoke at least one credit previously granted to the client.