VIRTUAL UPGRADE LAYER-BASED APPLICATION UPGRADE

1 . A system comprising:

a plurality of application hosts with each application host executing an application; and

a management node coupled to the plurality of application hosts via a network, wherein the management node comprises an application upgrade unit to:

install an upgrade agent in each application host requiring an upgrade of the application; and

execute the upgrade agent to:

create a virtual upgrade layer in a non-volatile storage device of each application host;

copy an application upgrade package and application data associated with the application to the virtual upgrade layer;

upgrade the application in the virtual upgrade layer of each application host using the application upgrade package and the application data; and

in response to receiving a go-live command, commit the upgraded application from the virtual upgrade layer to the non-volatile storage device of each application host.

2 . The system of claim 1 , wherein the application upgrade unit is to:

push the application upgrade package to each application host requiring the upgrade for storing in the non-volatile storage device of each application host, wherein the upgrade agent, when executed, is to copy the application upgrade package from the non-volatile storage device to the virtual upgrade layer of each application host.

3 . The system of claim 1 , wherein, in response to receiving the go-live command, the upgrade agent is to:

halt the application running in a volatile storage device of each application host;

uninstall the application from the non-volatile storage device;

move the upgraded application from the virtual upgrade layer to the non-volatile storage device; and

start running the upgraded application in the volatile storage device of each application host.

4 . The system of claim 1 , wherein, upon committing the upgraded application from the virtual upgrade layer to the non-volatile storage device, the upgrade agent is to:

output a prompt seeking user confirmation to determine a working status of the upgraded application;

when the upgraded application is working:

move the upgraded application from the virtual upgrade layer to the non-volatile storage device; and

delete the virtual upgrade layer from the non-volatile storage device.

5 . The system of claim 4 , wherein the application upgrade unit is to:

generate a pre-upgrade snapshot of the application in each application host prior to installing the upgrade agent, wherein when the upgraded application is not working, the upgrade agent is to:

revert each application host to the pre-upgrade snapshot of the application.

6 . The system of claim 1 , wherein the upgrade agent is to:

copy the application data associated with the application requiring the upgrade, residing in the non-volatile storage device and the volatile storage device, to the virtual upgrade layer of each application host.

7 . The system of claim 1 , wherein the upgrade agent is to:

upgrade the application in the virtual upgrade layer of each application host as a background process while the application is running in each application host.

8 . The system of claim 1 , wherein each application host comprises a physical host computing device or a virtual machine.

9 . A method comprising:

creating a virtual upgrade layer in a non-volatile storage device of an application host requiring an application upgrade;

copying application data associated with an application requiring the application upgrade, residing in the non-volatile storage device and a volatile storage device, to the virtual upgrade layer;

copying the application upgrade package to the virtual upgrade layer;

upgrading the application in the virtual upgrade layer using the application upgrade package and the application data; and

in response to receiving a go-live command, committing code corresponding to the upgraded application from the virtual upgrade layer to the non-volatile storage device of the application host.

10 . The method of claim 9 , wherein copying the application upgrade package to the virtual upgrade layer comprises:

receiving the application upgrade package to upgrade the application from a server;

storing the application upgrade package in the non-volatile storage device; and

upon creating the virtual upgrade layer, copying the application upgrade package from the non-volatile storage device to the virtual upgrade layer.

11 . The method of claim 9 , wherein committing the code corresponding to the upgraded application from the virtual upgrade layer to the non-volatile storage device comprises:

halting the application running in a volatile storage device of the application host;

uninstalling the application from the non-volatile storage device;

moving the upgraded application from the virtual upgrade layer to the non-volatile storage device; and

executing the upgraded application in the volatile storage device.

12 . The method of claim 9 , further comprising:

outputting a prompt seeking user confirmation to determine a working status of the upgraded application; and

when the upgraded application is working, deleting the virtual upgrade layer from the non-volatile storage device.

13 . The method of claim 9 , further comprising:

generating a pre-upgrade snapshot of the application in the application host prior to creating the virtual upgrade layer, wherein when the upgraded application is not working:

reverting the application host to the pre-upgrade snapshot of the application.

14 . The method of claim 9 , wherein the application host comprises a physical host computing device or a virtual machine running on the physical host computing device.

15 . The method of claim 9 , wherein upgrading the application in the virtual upgrade layer comprises:

upgrading the application in the virtual upgrade layer of the application host as a background process while the application is running in the application host.

16 . A non-transitory computer-readable storage medium storing instructions executable by a processor of a management node to:

create a virtual upgrade layer in a non-volatile storage device of each application host requiring an application upgrade;

copy an application requiring the application upgrade, residing in the non-volatile storage device and a volatile storage device, to the virtual upgrade layer of each application host;

copy the application upgrade package to the virtual upgrade layer of each application host;

upgrade the application in the virtual upgrade layer of each application host using the application upgrade package and the application data; and

schedule to commit the upgraded application from the virtual upgrade layer to the non-volatile storage device of each application host.

17 . The non-transitory computer-readable storage medium of claim 16 , further comprising instructions to:

commit the upgraded application from the virtual upgrade layer to the non-volatile storage device of each application host in accordance with the schedule.

18 . The non-transitory computer-readable storage medium of claim 16 , wherein instructions to commit the upgraded application from the virtual upgrade layer to the non-volatile storage device comprise instructions to:

halt the application running in a volatile storage device of the application host;

uninstall the application from the non-volatile storage device;

move the upgraded application from the virtual upgrade layer to the non-volatile storage device; and

execute the upgraded application in the volatile storage device.

19 . The non-transitory computer-readable storage medium of claim 16 , wherein instructions to upgrade the application in the virtual upgrade layer comprising instructions to:

isolate the upgrading of the application to the virtual upgrade layer of each application host while the application is running in each application host.

20 . The non-transitory computer-readable storage medium of claim 16 , further comprising instructions to:

when upgrading of the application is successful, delete the virtual upgrade layer from the non-volatile storage device upon committing the upgraded application from the virtual upgrade layer to the non-volatile storage device; and

when upgrading of the application is not successful, revert each application host to a pre-upgrade snapshot of the application.