Maintaining a Pool of Free Virtual Machines on a Server Computer

• US 20080201711A1
• Filed: 02/15/2008
• Published: 08/21/2008
• Est. Priority Date: 02/15/2007
• Status: Active Grant

• Current Assignee: Citrix Systems, Inc. (Cloud Software Group)
• Original Assignee: ClearCube Technology Incorporated
• Inventors: Amir Husain, Syed M.
• Granted Patent: US 8,176,486 B2
• Time in Patent Office: Days
• US Class Current: 718/1
• CPC Class Codes: G06F 11/1484 involving virtual machines
• CPC Class Codes: G06F 11/301 where the computing system is a virtual computing platform, e.g. logically partitioned systems virtual machines G06F9/45533; logical partitioning of resources G06F9/5077
• CPC Class Codes: G06F 2009/4557 Distribution of virtual machine instances; Migration and load balancing
• CPC Class Codes: G06F 2009/45575 Starting, stopping, suspending or resuming virtual machine instances
• CPC Class Codes: G06F 2009/45595 Network integration; Enabling network access in virtual machine instances
• CPC Class Codes: G06F 9/445 Program loading or initiating bootstrapping G06F9/4401; security arrangements for program loading or initiating G06F21/57
• CPC Class Codes: G06F 9/45504 Abstract machines for programme code execution, e.g. Java virtual machine [JVM], interpreters, emulators
• CPC Class Codes: G06F 9/45558 Hypervisor-specific management and integration aspects
• CPC Class Codes: G06F 9/5077 Logical partitioning of resources; Management or configuration of virtualized resources specific details on emulation or internal functioning of virtual machines G06F9/455
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 67/34 involving the movement of software or configuration parameters network booting or remote initial program loading [RIPL] G06F9/4416

Abstract

Various embodiments of a system and method for managing virtual machines on a server computer are described. According to one embodiment of the method, a pool of free virtual machines may be maintained on the server computer, e.g., where the number of virtual machines in the pool is specified by an administrator. In response to receiving a request to assign a virtual machine to a first user, the server computer may assign a first virtual machine from the pool to the first user and add a new virtual machine to the pool to replace the first virtual machine. In some embodiments the server computer may be one of a plurality of server computers in a server computer system. An administrator may be able to configure different pool sizes for different server computers in the system through a central user interface.

Claims

1. A computer-accessible storage medium storing program instructions executable to implement:

adding a group of free virtual machines executing on a first server computer to a pool, wherein each free virtual machine in the pool is available to be assigned to a user;

in response to receiving a first request to assign a virtual machine to a first user;

assigning a first virtual machine from the pool to the first user; and

adding a new free virtual machine to the pool to replace the first virtual machine.

2. The computer-accessible storage medium of claim 1, wherein the program instructions are further executable to implement:

receiving user input specifying a pool size N indicating a number of virtual machines for the pool, wherein N is a number greater than or equal to 1, wherein adding the group of free virtual machines to the pool comprises adding N free virtual machines to the pool.

3. The computer-accessible storage medium of claim 2, wherein the program instructions are further executable to implement:

adding a second virtual machine to the pool in response to de-assigning the second virtual machine from a second user; and

in response to determining that adding the second virtual machine to the pool caused the pool size to become greater than N, hibernating one or more of the virtual machines in the pool to reduce the pool size to N.

4. The computer-accessible storage medium of claim 1, wherein the program instructions are further executable to implement:

receiving information indicating a maximum number of concurrent users that can be assigned to virtual machines on the first server computer;

receiving a second request to assign a virtual machine to a second user;

assigning a second virtual machine from the pool to the second user; and

determining a first difference between the maximum number of concurrent users and a number of users currently assigned to virtual machines on the first server computer; and

determining whether to add a new free virtual machine to the pool to replace the second virtual machine based on the first difference and the pool size N.

5. The computer-accessible storage medium of claim 1,

wherein each free virtual machine in the pool is in an active state of execution.

6. The computer-accessible storage medium of claim 1,

wherein adding the new free virtual machine to the pool comprises creating the new free virtual machine and adding the new free virtual machine to the pool.

7. The computer-accessible storage medium of claim 1,

wherein, before the new free virtual machine is added to the pool, the new free virtual machine is in a state of hibernation;

wherein adding the new free virtual machine to the pool comprises returning the new free virtual machine to an active state of execution and adding the new free virtual machine to the pool.

8. The computer-accessible storage medium of claim 1,

wherein the pool on the first server computer is a first pool, wherein the program instructions are further executable to implement:

receiving first user input specifying a first pool size N indicating a number of virtual machines for the first pool;

receiving second user input specifying a second pool size M indicating a number of virtual machines for a second pool on a second server computer; and

adding a group of M free virtual machines executing on the second server computer to the second pool.

9. The computer-accessible storage medium of claim 8, wherein the program instructions are further executable to implement:

displaying a graphical user interface on a display for managing the first server computer and the second server computer;

wherein the first user input specifying the pool size N for the first pool on the first server computer and the second user input specifying the pool size M for the second pool on the second server computer are received to the graphical user interface displayed on the display.

10. A system comprising:

one or more processors; and

memory storing program instructions;

wherein the program instructions are executable by the one or more processors to implement;

adding a group of free virtual machines to a pool, wherein each free virtual machine in the pool is available to be assigned to a user;

in response to receiving a first request to assign a virtual machine to a first user;

assigning a first virtual machine from the pool to the first user; and

adding a new free virtual machine to the pool to replace the first virtual machine.

11. The system of claim 10, wherein the program instructions are further executable to implement:

receiving user input specifying a pool size N indicating a number of virtual machines for the pool, wherein N is a number greater than or equal to 1, wherein adding the group of free virtual machines to the pool comprises adding N free virtual machines to the pool.

12. The system of claim 11, wherein the program instructions are further executable to implement:

adding a second virtual machine to the pool in response to de-assigning the second virtual machine from a second user; and

in response to determining that adding the second virtual machine to the pool caused the pool size to become greater than N, hibernating one or more of the virtual machines in the pool to reduce the pool size to N.

13. The system of claim 10, wherein the program instructions are further executable to implement:

receiving information indicating a maximum number of concurrent users that can be assigned to virtual machines;

receiving a second request to assign a virtual machine to a second user;

assigning a second virtual machine from the pool to the second user; and

determining a first difference between the maximum number of concurrent users and a number of users currently assigned to virtual machines; and

determining whether to add a new free virtual machine to the pool to replace the second virtual machine based on the first difference and the pool size N.

14. The system of claim 10,

wherein adding the new free virtual machine to the pool comprises creating the new free virtual machine and adding the new free virtual machine to the pool.

15. The system of claim 10,

wherein, before the new free virtual machine is added to the pool, the new free virtual machine is in a state of hibernation;

wherein adding the new free virtual machine to the pool comprises returning the new free virtual machine to an active state of execution and adding the new free virtual machine to the pool.

16. A method comprising:

adding a group of free virtual machines executing on a first server computer to a pool, wherein each free virtual machine in the pool is available to be assigned to a user;

in response to receiving a first request to assign a virtual machine to a first user;

assigning a first virtual machine from the pool to the first user; and

adding a new free virtual machine to the pool to replace the first virtual machine.

17. The method of claim 16, further comprising:

receiving user input specifying a pool size N indicating a number of virtual machines for the pool, wherein N is a number greater than or equal to 1, wherein adding the group of free virtual machines to the pool comprises adding N free virtual machines to the pool.

18. The method of claim 17, further comprising:

adding a second virtual machine to the pool in response to de-assigning the second virtual machine from a second user; and

in response to determining that adding the second virtual machine to the pool caused the pool size to become greater than N, hibernating one or more of the virtual machines in the pool to reduce the pool size to N.

19. The method of claim 16, further comprising:

receiving information indicating a maximum number of concurrent users that can be assigned to virtual machines on the first server computer;

receiving a second request to assign a virtual machine to a second user;

assigning a second virtual machine from the pool to the second user; and

determining a first difference between the maximum number of concurrent users and a number of users currently assigned to virtual machines on the first server computer; and

determining whether to add a new free virtual machine to the pool to replace the second virtual machine based on the first difference and the pool size N.