Image cache collaboration between clients in remote desktop environments

1. A method for providing image cache collaboration between multiple client devices in a remote desktop environment, the method comprising:

detecting, by a virtual desktop agent executing on a host server, an update to at least a portion of a graphical user interface (GUI) of a virtual desktop executed on the host server for a first client device;

transmitting an image hash key of the update from the virtual desktop agent executing on the host server to a central cache manager executing on a connection server, wherein the connection server is a separate device from the host server and is configured to establish virtual desktop connection sessions for each of the client devices;

determining, by the central cache manager, that an image cache on a second client device currently contains image data needed to update the GUI of the virtual desktop for the first client device, wherein the central cache manager knows the contents of all image caches of each of the client devices that are connected to the connection server by using an agreed upon caching algorithm between the central cache manager and the client devices, wherein the agreed upon caching algorithm enables the central cache manager to determine, at the time of transmitting the image data to the client devices, whether the image data will be cached by the client devices; and

transmitting a message, from the central cache manager executing on the connection server to the first client device identifying the second client device that contains the image data, wherein the first client device requests the image data from the second client device in response to receiving said message.

2. The method of claim 1 , further comprising:

maintaining a table storing entries associating image hash keys with client devices, wherein each image hash key corresponds to a set of image data for a portion of the GUI, the set of image data stored on a client device identified by the corresponding entry in the table.

3. The method of claim 1 , wherein the first client device and the second client device reside within a first local area network (LAN) and wherein the server resides in a second LAN that is separate and distinct from the first LAN, and wherein the first client device and the second client device connect to the server over a wide area network (WAN) connections.

4. The method of claim 1 , wherein the second client device is configured to listen on a specified port designated for sending image cache data, and wherein:

in response to receiving the message, the first client obtains the internet protocol (IP) address of the second client and establishes a transfer control protocol (TCP) connection with the second client at the specified port.

5. The method of claim 4 , wherein the first client requests the image data from the second client using the connection and the second client transmits the image data from the image cache of the second client to the first client.

6. The method of claim 1 , wherein the virtual desktop is executed on a virtual machine managed by a hypervisor executed on the server, the virtual machine associated with a user of the first client device.

7. The method of claim 1 , wherein the central manager includes a table of image cache entries representing content in all image caches of every client device connected to the connection server.

8. A non-transitory computer readable storage medium comprising one or more sequences of instructions, the instructions when executed by one or more processors causing the one or more processors to execute the operations of:

detecting, by a virtual desktop agent executing on a host server, an update to at least a portion of a graphical user interface (GUI) of a virtual desktop executed on the host server for a first client device;

transmitting an image hash key of the update from the virtual desktop agent executing on the host server to a central cache manager executing on a connection server, wherein the connection server is a separate device from the host server and is configured to establish virtual desktop connection sessions for each of the client devices;

determining, by the central cache manager, that an image cache on a second client device currently contains image data needed to update the GUI of the virtual desktop for the first client device, wherein the central cache manager knows the contents of all image caches of each of the client devices that are connected to the connection server by using an agreed upon caching algorithm between the central cache manager and the client devices, wherein the agreed upon caching algorithm enables the central cache manager to determine, at the time of transmitting the image data to the client devices, whether the image data will be cached by the client devices; and

transmitting a message, from the central cache manager executing on the connection server to the first client device identifying the second client device that contains the image data, wherein the first client device requests the image data from the second client device in response to receiving said message.

9. The non-transitory computer readable storage medium of claim 8 , further comprising instructions to cause the one or more processors to:

maintain a table storing entries associating image hash keys with client devices, wherein each image hash key corresponds to a set of image data for a portion of the GUI, the set of image data stored on a client device identified by the corresponding entry in the table.

10. The non-transitory computer readable storage medium of claim 8 , wherein the first client device and the second client device reside within a first local area network (LAN) and wherein the server resides in a second LAN that is separate and distinct from the first LAN, and wherein the first client device and the second client device connect to the server over a wide area network (WAN) connections.

11. The non-transitory computer readable storage medium of claim 8 , wherein the second client device is configured to listen on a specified port designated for sending image cache data, and wherein:

in response to receiving the message, the first client obtains the internet protocol (IP) address of the second client and establishes a transfer control protocol (TCP) connection with the second client at the specified port.

12. The non-transitory computer readable storage medium of claim 11 , wherein the first client requests the image data from the second client using the connection and the second client transmits the image data from the image cache of the second client to the first client.

13. The non-transitory computer readable storage medium of claim 8 , wherein the virtual desktop is executed on a virtual machine managed by a hypervisor executed on the server, the virtual machine associated with a user of the first client device.

14. The non-transitory computer readable storage medium of claim 8 , wherein the central manager includes a table of image cache entries representing content in all image caches of every client device connected to the connection server.

15. A computing system, comprising:

one or more processors; and

memory including instructions that when executed by the one or more processors, cause the computing system to:

detect, by a virtual desktop agent executing on a host server, an update to at least a portion of a graphical user interface (GUI) of a virtual desktop executed on the host server for a first client device;

transmit an image hash key of the update from the virtual desktop agent executing on the host server to a central cache manager executing on a connection server, wherein the connection server is a separate device from the host server and is configured to establish virtual desktop connection sessions for each of the client devices;

determine, by the central cache manager, that an image cache on a second client device currently contains image data needed to update the GUI of the virtual desktop for the first client device, wherein the central cache manager knows the contents of all image caches of each of the client devices that are connected to the connection server by using an agreed upon caching algorithm between the central cache manager and the client devices, wherein the agreed upon caching algorithm enables the central cache manager to determine, at the time of transmitting the image data to the client devices, whether the image data will be cached by the client devices; and

transmit a message, from the central cache manager executing on the connection server to the first client device identifying the second client device that contains the image data, wherein the first client device requests the image data from the second client device in response to receiving said message.

16. The computing system of claim 15 , wherein the memory further includes instructions that cause the computing system to:

maintain a table storing entries associating image hash keys with client devices, wherein each image hash key corresponds to a set of image data for a portion of the GUI, the set of image data stored on a client device identified by the corresponding entry in the table.

17. The computing system of claim 15 , wherein the first client device and the second client device reside within a first local area network (LAN) and wherein the computing device resides in a second LAN that is separate and distinct from the first LAN, and wherein the first client device and the second client device connect to the computing device over wide area network (WAN) connections.

18. The computing system of claim 15 , wherein the second client device is configured to listen on a specified port designated for sending image cache data, and wherein:

in response to receiving the message, the first client obtains the internet protocol (IP) address of the second client and establishes a transfer control protocol (TCP) connection with the second client at the specified port.

19. The computing system of claim 18 , wherein the first client requests the image data from the second client using the connection and the second client transmits the image data from the image cache of the second client to the first client.

20. The computing system of claim 15 , wherein the virtual desktop is executed on a virtual machine managed by a hypervisor executed on the computing device, the virtual machine associated with a user of the first client device.