# Patent

## Title
Application state backup and restoration across multiple devices

## Abstract

Technology for a method for backing up and restoring application state across multiple devices is disclosed herein. The method includes running an instance of a computer application at a first electronic device, determining a backup event that occurs in the first electronic device, wherein the backup event suggests a backup of application state data and the application state data represent an application state of the computer application at the backup event, and transmitting the application state data of the computer application to a remote storage service, in response to the backup event. A second electronic device can retrieve the application state data from the remote storage service and restore the application state.

## Background
PRIORITY CLAIM
This application claims to the benefit of U.S. Provisional Patent Application No. 61/708,794, entitled “CLOUD COMPUTING INTEGRATED OPERATING SYSTEM”, which was filed on Oct. 2, 2012, which is incorporated by reference herein in its entirety.
This application is also a continuation-in-part of U.S. patent application Ser. No. 13/772,163, entitled “APPLICATION STATE SYNCHRONIZATION ACROSS MULTIPLE DEVICES”, which was filed on Feb. 20, 2013, which is incorporated by reference herein in its entirety.


FIELD OF THE INVENTION
At least one embodiment of the present invention pertains to cloud computing, and more particularly, to automatic backup and restoration of application states across multiple devices using cloud storage.
BACKGROUND
Application state data are data used to record the running status of a computer application. One example of application state data is a game save for a game application. A game save is a piece of digitally stored information about the progress of a user operating the game application. The game save can be reloaded later, so that the user can continue where he stopped. The user instructs the game application to generate a game save (i.e. save the game) to prevent the loss of progress in the game, especially when he is interrupted or ending a game session.
Sharing and backing up game saves among users have been common for many years. Originally by swapping memory cards with game saves, users could help each other to unlock features in a game application. With the growing popularity of the Internet, users start to upload their game saves from their devices to Internet servers. By downloading a game save from an Internet server, a user can continue the progress of the game on the device on which he played the game or another device such as a computer, game console, or smart phone. However, to achieve the goal of continuing the progress on another device, the user needs to deliberately instruct the device to save the game progress (i.e. game save) and to upload the game save to a server or a memory card. Then the user needs to download the game from the server or the memory card to the other device, and then instructs the other device to load the game save. The whole process is tedious and requires many user interventions. Furthermore, the process only works for game applications that are specifically designed with game saving functionalities.
SUMMARY
Techniques introduced here provide an automatic mechanism for backing up and restoring application state across multiple devices. In accordance with the techniques introduced here, a method includes running an instance of a computer application at a first electronic device, and determining a backup event that occurs in the first electronic device. The backup event suggests a backup of application state data and the application state data represent an application state of the computer application at the backup event. The method further includes transmitting the application state data of the computer application to a remote storage service, in response to the backup event. Another electronic device can retrieve the application state data of the computer application from the remote storage service, and restore the computer application to the application state using the application state data.
The backup proceeds automatically on the background of the operating system of the device and is transparent to the user as well as the application. The user can restore the application state of the application running on the same device or on another device at where the state of the application has been backed up. The application state backup and restore can be achieved at the operating system level of the devices. There is no special treatment or design needed for the computer application itself. Any computer application capable of running on such an operating system can take advantage of the application state backup and restore functionality.
Other aspects of the technology introduced here will be apparent from the accompanying figures and from the detailed description which follows.



BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features and characteristics of the present invention will become more apparent to those skilled in the art from a study of the following detailed description in conjunction with the appended claims and drawings, all of which form a part of this specification. In the drawings:
FIG. 1 illustrates an example system for application state synchronization between electronic devices.
FIG. 2 illustrates an example of an application states synchronization process across multiple electronic devices.
FIG. 3 illustrates an example operating system of an electronic device.
FIG. 4 illustrates an example of an application state data of a computer application collected by an operating system.
FIG. 5 illustrates an example of an application state synchronization process based on a user defined synchronization scheme.
FIG. 6 illustrates an example of an application state backup and restoration process.
FIG. 7 is a high-level block diagram showing an example of the architecture of a computer server, which may represent any computer running the database management system described herein.



DETAILED DESCRIPTION
References in this specification to “an embodiment,” “one embodiment,” or the like, mean that the particular feature, structure, or characteristic being described is included in at least one embodiment of the present invention. Occurrences of such phrases in this specification do not all necessarily refer to the same embodiment, however.
A method of application state synchronization across devices is described herein. For example, a user plays a game on his smart phone, and stops playing and turns off the screen of his smart phone. The state of the game application is synchronized between his smart phone and other electronic devices via a cloud system. He can pick up his tablet computer and continue to play the game from where he left off. The synchronization is not necessarily directly triggered by a user intervention. For instance, the synchronization can be automatically triggered when the screen of the smart phone is turned off, or the user closes the game on his smart phone. The synchronization proceeds automatically on the background and is transparent to the user. Furthermore, the cloud system can analyze various information, including device profile, user profile and user history, to determine state of which application is to be synchronized and which device the state is synchronized to.
FIG. 1 illustrates an example system for application state synchronization between electronic devices. The system includes a cloud storage service 110 configured to store state data for applications. In one embodiment, the cloud storage service 110 can be a storage cluster having computer nodes interconnected with each other by a network. The storage cluster can communicate with other electronic devices via the Internet. The cloud storage service 110 contains storage nodes 112. Each of the storage nodes 112 contains one or more processors 114 and storage devices 116. The storage devices can include optical disk storage, RAM, ROM, EEPROM, flash memory, phase change memory, magnetic cassettes, magnetic tapes, magnetic disk storage or any other computer storage medium which can be used to store the desired information.
A cloud synchronization interface 120 can also be included to receive data to be stored in the cloud storage service. The cloud synchronization interface 120 can include network communication hardware and network connection logic to receive the information from electronic devices. The network can be a local area network (LAN), wide area network (WAN) or the Internet. The cloud synchronization interface 120 may include a queuing mechanism to organize the received synchronization data to be stored in the cloud storage service 110. The cloud synchronization interface 120 can communicate with the cloud storage service 110 to send requests to the cloud storage service 110 for storing application state data and retrieving data.
An electronic device 130 includes an operating system 132 to manage the hardware resources of the electronic device 130 and provide services for running computer applications 134. The computer application 134 stored in the electronic device 130 require the operating system 132 to properly run on the device 130. The electronic device 130 can backup application states of the computer applications 134 to the cloud storage service 110. The electronic device 130 includes at least one local storage device 138 to store the computer applications, application data, and user data. The electronic device 130 can synchronize the application state data with the cloud storage service 110 via the cloud synchronization interface 120. The electronic device 130 or 140 can be a desktop computer, a laptop computer, a tablet computer, an automobile computer, a game console, a smart phone, a personal digital assistant, or other electronic devices capable of running computer applications, as contemplated by a person having ordinary skill in the art.
The computer applications 134 stored in the electronic device 130 can include applications for general productivity and information retrieval, including email, calendar, contacts, and stock market and weather information. The computer applications 134 can also include applications in other categories, such as mobile games, factory automation, GPS and location-based services, banking, order-tracking, ticket purchases or any other categories as contemplated by a person having ordinary skill in the art.
The operating system 132 of the electronic device 130 includes a state synchronization module 136 to backup application state information from the local storage. The state synchronization module 136 can operate to keep the application state data from the electronic device 130 in synchronization with the cloud storage service 110 and other devices.
Similarly, another electronic device 140 can also synchronize the application state with the cloud storage service 110. The electronic devices 130 and 140 can synchronize the application states between each other via the cloud storage service 110. For instance, the electronic device 130 can synchronize the application state of a computer application to the cloud storage service 110. The cloud storage service 110 communicates with the electronic device 140 to know that the electronic device 140 also contain this computer application and the application state of this computer application is not updated on the electronic device 140. In turn, the cloud storage service 110 sends the application state data to the electronic device 140. Thus, the application state of this computer application is synchronized between the electronic devices 130 and 140.
In one embodiment, the synchronization for backups from the electronic devices 130 and 140 to the cloud storage service 110 may take place on a configurable periodic basis, such as an hour or a day. In other words, the synchronization is scheduled to take place on a periodic basis. The scheduled synchronization can also check for updates that can be sent from the cloud storage service 110 to the electronic devices 130 and 140.
Another type of synchronization can be a triggered when an event occurs on the electronic device 130 or 140, and then the state synchronization module can initialize the application state data synchronization with the cloud storage service 110. The triggered synchronization does not need the intervention from the user. For instance, a user turns off the screen of the electronic device 130. The screen turning off event can trigger an application state data synchronization with the cloud storage service 110 as well as other electronic devices. However, the user does not need to specifically instruct the device to synchronize; the user does not even need to realize that the synchronization occurs.
In one embodiment, the backup event can be any of the following events: the screen of the electronic device being turned off, the instance of the computer application being closed, the instance of the computer application being paused, the instance of the computer application having been run continuously for a preconfigured period of time, the instance of the computer application being switched by another application, the instance of the computer application being switched from the foreground to a background of the operating system, a battery level of the electronic device being below a preconfigured value, the electronic device turning off, the electronic device switching to standby mode, a clock of the electronic device reaching a preconfigured time of day, and the electronic device being in a preconfigured location
In one embodiment, the synchronization can be a delta synchronization where the electronic device 130 or 140 detects a change (i.e. delta) of application state data and only the changed data or difference are synchronized to the cloud storage device 110.
Any electronic device running an operating system having the state synchronization module can initialize the application state synchronization. In addition, the cloud storage service 110 can also initialize the application state synchronization. In one embodiment, the cloud storage service 110 may analyze the electronic devices to determine which device is to be synchronized and state data of which application are to be synchronized.
FIG. 2 illustrates an example of an application states synchronization process across multiple electronic devices. At step 205, a cloud storage system identifies a plurality of electronic devices capable of synchronizing application state data with the cloud storage system. The electronic devices may be capable of communicating with the cloud storage system via a network, such as the Internet, a WiFi Network, or a cellular phone network. At step 210, one of the identified electronic devices runs an application.
At step 215, a backup event is determined to occur at the electronic device. The operating system of the electronic device automatically determines the backup event, without the intervention from the user. The user does not specifically instruct the backup event. The user does not even need to realize the backup event. There is no need for a sync button, a sync gesture, a sync menu item, or a sync command. In other words, the operating system of the device makes the determination of a backup event. For instance, the operating system may recognize an event of the screen being turned off as a backup event. The operating system may also recognize an event of a running application being closed or being switched by another application as a backup event. The operating system may further recognize an event of a system standby as a backup event. The operating system of the device can determine other types of backup events, as contemplated by a person having ordinary skill in the art.
Once the operating detects a backup event, the operating system of the electronic device uploads the application state data of the computer application onto the cloud storage system at step 220. The operating system of the device may decide to immediately start uploading the application state data after the backup event, or start the upload a certain amount of time after the backup event. For instance, if the electronic device detects that there is another electronic device of the same user in a very close proximity, the operating system of the device may decide to start the upload immediately because of a high possibility that the user will start using the other device soon. In another embodiment, the electronic device may decide to start the upload at a certain time of day or at certain location. For instance, the electronic device may decide to start the upload at midnight 12 AM and at the user's home (determined by GPS location or WiFi location), so that the upload of the application state data does not intervene with normal operation of the device.
In one embodiment, the developer of the computer application does not need to specifically write any implementation for uploading the application state data. For example, there are no API calls embedded in the computer application for the application state data. The state synchronization module of the operating system is responsible for monitoring, collecting and uploading the application state data. In some embodiments, the state synchronization module compares the current application state on the device and the application state already stored in the cloud storage service. If the current application state is newer than the application state stored in the cloud storage service, the state synchronization module determines a difference (i.e. delta) between the current application state data and the application state data stored in the cloud storage service. In this way, the state synchronization module only needs to upload the difference to the cloud storage service. The cloud storage service is responsible for incorporating the difference into the application state data already stored.
At step 225, the cloud storage system performs an analysis on the device profile, user profile and user history, to determine which device the state is synchronized to. For instance, in one embodiment, the cloud storage system determines the devices that the same user is using (e.g. the devices which have established the user's user account). In another embodiment, the analysis is based on usage pattern. For example, the cloud storage service can determine to synchronize the application state to devices that the user has been frequently used during a specific time period, e.g. a week. Or the cloud storage service can determine to synchronize the application state to devices on which the user has been running that computer application. In yet another embodiment, the analysis is based on a proximity algorithm. For example, the cloud storage service can determine to synchronize the application state to devices that are physically close to the device in step 210. The proximity may be determined by GPS locations, WiFi network locations, cellular networking locations or the combination thereof. In still another embodiment, the analysis is based on the types of applications installed on the devices. For example, the cloud storage service can determine to synchronize the application state to devices that have instances of that application installed, or devices that have similar applications installed. Furthermore, the analysis can be determined by a combination of the above techniques, as well as any other device or user information as contemplated by a person having ordinary skill in the art.
The same types of analysis disclosed in the previous paragraph are used in determining the priority of synchronization. For instance, if there are application state data for multiple applications in the cloud storage service to be synchronized. The cloud storage service may determine to synchronize the state data for one application because the user has been frequently using that application during a recent time period, e.g. a week. In one embodiment, the cloud storage service decides a priority list including a reference to the application state data for the computer application, wherein the priority list regulates the order of transmitting the application state data for the computer application and data for other applications based on the analyzing of the user profile and the hardware profiles of electronic devices.
In some embodiments, the analysis is performed after the cloud storage system receives application state data from a device. In some other embodiments, the analysis can be performed before the cloud storage system receives any application state data or before the backup event occurs.
At step 230, the cloud storage system sends the application state data to one or more devices that are identified by the analysis. The identified devices receive the application state data. Therefore, the instances of the application running on the devices are synchronized with the most up-to-date state. A user can run an instance of the application on any of these devices and the instance of the application resumes from the most up-to-date state. In one embodiment, the cloud storage system further sends an instruction to each of the identified devices to run an instance of the computer application by resuming the application state at the backup event at step 235.
In one embodiment, the application state data of a computer application may include application memory data, application local storage data, hardware configuration data, and user account configuration data. The state synchronization module of the operating system is capable of collecting these data and uploading the data as included in the application state data to the cloud storage service. Based on the application state data, an operating system of another electronic device can recreate the same environment and status of the application on the other electronic device.
In some embodiments, the electronic devices are capable of synchronizing application state data between each other via a network, such as a WiFi network, Bluetooth network, or a cellular phone network. Each of the electronic devices contains a network component configured to directly synchronize the application state data with another electronic device.
FIG. 3 illustrates an example operating system of an electronic device, according to one embodiment. The operating system 300 includes a kernel 304. The kernel 304 provides interfaces to hardware of the electronic device for the computer applications running on top of the kernel 304, and supervises and controls the computer applications. The kernel 304 isolates the computer applications from the hardware. The kernel 304 may include one or more intervening sources that can affect execution of a computer application. In one embodiment, the kernel 304 includes a network I/O module 306, a file I/O module 308, multi-threading module 310, user input 314, system interrupts 316, and shared memory access 318.
A state synchronization module 330 runs on top of the kernel 304. The state synchronization module 330 monitors the information from the intervening sources of the kernel 304 and records state data according the information. In the example of FIG. 3, a computer application 340 includes a binary executable code 342 that can run on top of the operating system 300. The computer application 340 can further include static and dynamic libraries 344 that are referenced by the binary executable code 342 during application running. In one embodiment, the state synchronization module 330 runs in a user space file system (e.g. FUSE) on top of a Linux kernel. In another embodiment, the state synchronization module 330 runs in a kernel file system.
FIG. 4 illustrates an example of an application state data of a computer application collected by an operating system according to one embodiment. The application state data 400 of a computer application may include application memory data 402, application local storage data 404, hardware configuration data 406, and user account configuration data 408. In some other embodiments, the application state data can be all of or any combination of some of the fields 402, 404, 406 and 408. When the computer application is running, the state information in memory section (i.e. the application memory data 402) allocated for the application is being updated by the running application. The state synchronization module of the operating system monitors the application memory data 402, and uploads the data to a cloud storage service in response to the backup event. Furthermore, the computer application can update certain data on a local storage of the electronic device. The state synchronization module of the operating system can include the application local storage data 404 into the application state data 400. In some embodiments, the electronic device includes a memory device, e.g. flash memory, as both the memory and the local storage. Therefore, the application memory data 402 and application local storage data 404 can be one section of data that exists on the memory device of the electronic device.
The application state data 400 may further include hardware configuration data 406. For instance, the state synchronization module may record the current device sound volume level and the screen brightness level when the application is running. These device sound volume level and the screen brightness level are recorded as part of the hardware configuration data 405 and will be uploaded to the cloud storage service. Therefore, after another device is synchronized with the application state data and starts to resume running the application, the other device automatically adjusts the sound volume level and screen brightness level as on the previous device. Moreover, the application state data 400 may include user account configuration data 408. The user account configuration data 408 may include the user's preferences and choices regarding the computer application and the operating system environment for running the computer application. For instance, the user account configuration data 408 may include information about the user's language preference. Assuming the computer application is a game supporting both English and Chinese languages for user interface in the game, the user has selected the English language as the preferred language. The state synchronization module records the user's language preference as a part of the user account configuration data 408. The user account configuration data 408 is synchronized to another device via the cloud storage service. When the other device starts to resume running the application, the application will use the English language for the game interface, as indicated by the user account configuration data 408.
In some embodiments, a user can define a synchronization scheme to control the way how and when the synchronization process performs. FIG. 5 illustrates an example of an application state synchronization process based on a user defined synchronization scheme. At step 505, a cloud storage service receives an instruction of a synchronization scheme from a user. The synchronization scheme includes rules of how and when the synchronization process performs. For example, in one embodiment, the synchronization scheme can define a synchronization rule between two electronic devices, a smart phone and a tablet computer, for application state of a game application. The synchronization rule specifies that one of the electronic devices start attempting to synchronize application state to the other device, as soon as the game application is closed or the screen of the device being turned off.
Assuming the smart phone is the current device running the game application, at step 510, the operating system of the smart phone checks whether the game application is closed by the user. If the game application is closed, the process continues to step 520. Otherwise, at step 515 the operating system of the smart phone continues to check whether the screen of the smart phone is turned off. If the screen is turned off, the process continues to step 520. Otherwise, the process goes back to check the status as in steps 510 and 520 in a predetermined time period.
At step 520, the smart phone uploads application state data of the game application to the cloud storage system. The schedule of the uploading can depend on a type and a speed of a connection between the smart phone and the could storage system. For instance the schedule can be determined so that the uploading is delayed to use a WiFi connection, to avoid the uploading using a cellular data connection (e.g. 3G or LTE). At step 525, the cloud storage system reads the synchronization scheme defined by the user. At step 530, the cloud storage system checks whether the other device, i.e. the tablet computer, is currently being connected with the cloud storage system. If the tablet computer is connected with the cloud storage system, the system sends the application state data to the tablet computer according to the synchronization scheme at 535. Otherwise, the cloud storage system continues to check the connection with the tablet computer on a periodic basis.
At step 540, when the user starts to use the tablet computer, the tablet computer starts to run an instance of the game application by resuming the application state recorded in the synchronized application state data.
In some embodiments, an electronic device can automatically back up the application state data to a cloud storage service and restore the application state be retrieving the application state data from the cloud storage service. FIG. 6 illustrates an example of an application backup and restore process. At step 605, an first electronic device runs an instance of a computer application. At step 610, the first electronic device determines a backup event that occurs in the first electronic device. The backup event suggests a backup of application state data and the application state data represent an application state of the computer application at the backup event. The backup event can be automatic and does not need to be instructed by a user who is operating the instance of the computer application.
At step 615, the first electronic device transmits the application state data of the computer application to a remote storage service, in response to the backup event. The remote storage service can be a cloud computing service. Alternatively, the remote storage service can belong to a cloud storage service cluster. The first electronic device is capable of transmitting the application state data to the remote storage service via a network, which can include the Internet, a WiFi network, or a cellular phone network. In one embodiment, the first electronic device can immediately transmit the application state data of the computer application to a remote storage service in real time without substantial delay, in response to the backup event.
The application state data of the computer application can be transmitted to the remote storage service at a preconfigured time of day or when the first electronic device is at a preconfigured location, in response to the backup event. Alternatively, the application state data of the computer application can be transmitted to the remote storage service at a schedule depending on a type and a speed of a connection between the first electronic device and the remote storage service, in response to the backup event. The schedule can be determined so that the transmitting is delayed to use a WiFi connection, to avoid the transmitting using a cellular data connection. The backup can be incremental. For instance, a difference between the application state data of the computer application and previously transmitted application state data can be transmitted to a remote storage service, in response to the backup event.
In some embodiments, the first electronic device may further determine a restore event that occurs in the electronic device, wherein the restore event suggests a restore of the application state of the computer application at the second electronic device; and instructs the remote storage service to transmit the application state data of the computer application to the second electronic, in response to the restore event.
Alternatively, a second electronic device can perform the process of restoring the application state. At step 620, the second electronic device determines a restore event that occurs in a second electronic device. The restore event suggests a restore of the application state of the computer application at the second electronic device. At step 625, the second electronic device can further instruct the remote storage service to transmit the application state data of the computer application to the second electronic device, in response to the restore event. At step 630, the second electronic device restores the computer application to the application state using the application state data.
FIG. 7 is a high-level block diagram showing an example of the architecture of a computer, which may represent any electronic device or any server within a cloud storage service as described herein. The server 700 includes one or more processors 710 and memory 720 coupled to an interconnect 730. The interconnect 730 shown in FIG. 7 is an abstraction that represents any one or more separate physical buses, point to point connections, or both connected by appropriate bridges, adapters, or controllers. The interconnect 730, therefore, may include, for example, a system bus, a Peripheral Component Interconnect (PCI) bus or PCI-Express bus, a HyperTransport or industry standard architecture (ISA) bus, a small computer system interface (SCSI) bus, a universal serial bus (USB), IIC (I2C) bus, or an Institute of Electrical and Electronics Engineers (IEEE) standard 1394 bus, also called “Firewire”.
The processor(s) 710 is/are the central processing unit (CPU) of the server 700 and, thus, control the overall operation of the server 700. In certain embodiments, the processor(s) 710 accomplish this by executing software or firmware stored in memory 720. The processor(s) 710 may be, or may include, one or more programmable general-purpose or special-purpose microprocessors, digital signal processors (DSPs), programmable controllers, application specific integrated circuits (ASICs), programmable logic devices (PLDs), trusted platform modules (TPMs), or the like, or a combination of such devices.
The memory 720 is or includes the main memory of the server 700. The memory 720 represents any form of random access memory (RAM), read-only memory (ROM), flash memory, or the like, or a combination of such devices. In use, the memory 720 may contain a code 770 containing instructions according to the techniques disclosed herein.
Also connected to the processor(s) 710 through the interconnect 730 are a network adapter 740 and a storage adapter 750. The network adapter 740 provides the server 700 with the ability to communicate with remote devices, over a network and may be, for example, an Ethernet adapter or Fibre Channel adapter. The network adapter 740 may also provide the server 700 with the ability to communicate with other computers. The storage adapter 750 allows the server 700 to access a persistent storage, and may be, for example, a Fibre Channel adapter or SCSI adapter.
The code 770 stored in memory 720 may be implemented as software and/or firmware to program the processor(s) 710 to carry out actions described above. In certain embodiments, such software or firmware may be initially provided to the server 700 by downloading it from a remote system through the server 700 (e.g., via network adapter 740).
The techniques introduced herein can be implemented by, for example, programmable circuitry (e.g., one or more microprocessors) programmed with software and/or firmware, or entirely in special-purpose hardwired circuitry, or in a combination of such forms. Special-purpose hardwired circuitry may be in the form of, for example, one or more application-specific integrated circuits (ASICs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), etc.
Software or firmware for use in implementing the techniques introduced here may be stored on a machine-readable storage medium and may be executed by one or more general-purpose or special-purpose programmable microprocessors. A “machine-readable storage medium”, as the term is used herein, includes any mechanism that can store information in a form accessible by a machine (a machine may be, for example, a computer, network device, cellular phone, personal digital assistant (PDA), manufacturing tool, any device with one or more processors, etc.). For example, a machine-accessible storage medium includes recordable/non-recordable media (e.g., read-only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media; flash memory devices; etc.), etc.
The term “logic”, as used herein, can include, for example, programmable circuitry programmed with specific software and/or firmware, special-purpose hardwired circuitry, or a combination thereof.
In addition to the above mentioned examples, various other modifications and alterations of the invention may be made without departing from the invention. Accordingly, the above disclosure is not to be considered as limiting and the appended claims are to be interpreted as encompassing the true spirit and the entire scope of the invention.

## Claims

1. A computer-implemented method comprising:
running an instance of a computer application at a first electronic device;
determining a backup event that occurs in the first electronic device, wherein the backup event suggests a backup of application state data and the application state data represents an application state of the computer application at the backup event;
transmitting the application state data of the computer application to a remote storage service, in response to the backup event;
determining a restore event that occurs in a second electronic device, wherein the restore event suggests a restore of the application state of the computer application at the second electronic device; and
instructing the remote storage service to transmit the application state data of the computer application to the second electronic device, in response to the restore event, so that the second electronic device restores the computer application to the application state using the application state data,
wherein the step of transmitting includes transmitting the application state data of the computer application to a remote storage service at a schedule depending on a type and a speed of a connection between the first electronic device and the remote storage service, in response to the backup event.

2. The computer-implemented method of claim 1, wherein the first electronic device executes the transmitting the application state data at a background of an operating system of the first electronic device without user intervention.

3. The computer-implemented method of claim 1, further comprising
determining a restore event that occurs in the first electronic device, wherein the restore event suggests a restore of the application state of the computer application at the first electronic device; and
retrieving the application state data of the computer application from the remote storage service, in response to the restore event, so that the first electronic device can restore the computer application to the application state using the application state data.

4. The computer-implemented method of claim 1, further comprising:
receiving a confirmation that the computer application has been restored to the application state using the application state data.

5. The computer-implemented method of claim 1, wherein the remote storage service is a cloud computing service or the remote storage service belongs to a cloud storage service cluster.

6. The computer-implemented method of claim 1, wherein the backup event is not instructed by a user who is operating the instance of the computer application.

7. The computer-implemented method of claim 1, wherein the sync event is an event of the screen of the first electronic device being turned off.

8. The computer-implemented method of claim 1, wherein the first electronic device is capable of transmitting the application state data to the remote storage service via a network.

9. The computer-implemented method of claim 7, wherein the network includes the Internet, a WiFi network, or a cellular phone network.

10. The computer-implemented method of claim 1, wherein the step of transmitting includes:
immediately transmitting the application state data of the computer application to a remote storage service, in response to the backup event.

11. The computer-implemented method of claim 1, wherein the step of transmitting includes:
transmitting the application state data of the computer application to a remote storage service at a preconfigured time of day or when the first electronic device is at a preconfigured location, in response to the backup event.

12. The computer-implemented method of claim 1, wherein the backup event is an event from events including:
the instance of the computer application being closed,
the instance of the computer application being paused,
the instance of the computer application has been continuously running for a preconfigured period of time,
the instance of the computer application being switched by another application,
a battery level of the first electronic device being below a preconfigured value,
the first electronic device turning off,
the first electronic device switching to standby mode,
a clock of the first electronic device reaching a preconfigured time of day, or
the first electronic device being at a preconfigured location.

13. The computer-implemented method of claim 11, wherein the schedule is determined so that the transmitting is delayed to use a WiFi connection, to avoid the transmitting using a cellular data connection.

14. The computer-implemented method of claim 1, wherein the step of transmitting includes:
transmitting a difference between the application state data of the computer application and previously transmitted application state data to a remote storage service, in response to the backup event.

15. An electronic device comprising:
a processor;
a memory storing instructions which, when executed by the processor, cause the electronic device to perform a process including:
running an instance of a computer application at the electronic device,
determining a backup event that occurs in the electronic device, wherein the backup event suggests a backup of application state data and the application state data represents an application state of the computer application at the backup event, and
transmitting the application state data of the computer application to a storage server, in response to the backup event,
wherein the application state data is used by another electronic device to restore the computer application to the application state on the other electronic device,
wherein transmitting the application state data includes transmitting the application state data of the computer application to a remote storage service at a schedule depending on a type and a speed of a connection between the first electronic device and the remote storage service, in response to the backup event.

16. The electronic device of claim 15, wherein the process further includes:
determining a restore event that occurs in the electronic device, wherein the restore event suggests a restore of the application state of the computer application at the electronic device; and
retrieving application state data of the computer application from the storage server, in response to the restore event.

17. The electronic device of claim 16, wherein the process further includes:
restoring the computer application to the application state at the electronic device using the application state data.

18. The electronic device of claim 15, wherein the application state data includes application memory data, application local storage data, hardware configuration data, or user account configuration data.

19. The electronic device of claim 15, wherein the computer application is a game application and the application state data includes game save data for the game application.

20. A computer-implemented method comprising:
receiving application state data from a first electronic device, wherein the application state data represents an application state at a backup event of a computer application running at the first electronic device;
determining a user identity for a user who runs the computer application at the first electronic device;
receiving a notice of a restore event including the user identity;
identifying the application state data associated with the user identity; and
transmitting the application state data to a second electronic device, wherein the application state data is utilized by the computer application to resume the application state at the restore event at the second electronic device,
wherein the step of transmitting includes transmitting the application state data of the computer application to a remote storage service at a schedule depending on a type and a speed of a connection between the first electronic device and the remote storage service, in response to the backup event.

21. A cloud based server comprising:
a processor;
a memory storing instructions which, when executed by the processor, cause the cloud based server to perform a process including:
receiving a notice of a backup event from a first electronic device, wherein the backup event suggests a backup of application state data and the application state data represent an application state of a computer application running at the first electronic device at the backup event;
receiving a notice of a restore event from a second electronic device, wherein the restore event suggests a restore of the application state of the computer application at the second electronic device;
receiving the application state data of the computer application from the first electronic device in response to the backup event; and
transmitting the application state data to the second electronic device in response to the notice of the restore event from the second electronic device,
wherein a transmission of the application state data from the first electronic device, in response to the backup event, to the cloud based server, is at a schedule depending on a type and a speed of a connection between the first electronic device and the cloud based server.

22. The cloud based server of claim 21, wherein the cloud based server receives the application state data from the first electronic device in such a manner that the first electronic device processes the application state data at a background of an operating system of the first electronic device without user intervention.

23. The cloud based server of claim 21, wherein the process further includes:
determining a priority list including a reference to the application state data, wherein the priority list regulates the order of transmitting the application state data for the computer application and data for other applications based on an analysis of a user profile and a hardware profile of at least the first electronic device.

24. An electronic device comprising:
a processor;
a non-transitory computer-readable medium storing instructions which, when executed by the processor, cause the electronic device to perform operations including:
executing a computer application;
generating application state data that represent an application state of the computer application at a background of an operating system of the electronic device without user intervention;
sending out the application state data to a cloud service, the sending of the application state data to the cloud service being triggered by a backup event, wherein the sending of the application state data to the cloud service is at a schedule depending on a type and a speed of a connection between the electronic device and the cloud service; and
instructing another electronic device to retrieve the application state data from the cloud service to restore the application state of the computer application on the other electronic device.

25. The electronic device of claim 24, wherein the application state data can be generated at any moment during the execution of the computer application, or continuously generated during the execution of the computer application.

26. The electronic device of claim 24, wherein the operating system of the electronic device sends the application state data according to a synchronization scheme defined by a user on how and when to transmit.

27. The electronic device of claim 24, wherein the operating system includes a state module responsible for monitoring, collecting and transmitting the application state data.