Patent Application
20090235353
Increasingly software applications are being hosted on the Internet. Because customers frequently have specific requirements for their applications or need tailored customizations, there is a need to support custom software applications on the Internet. Therefore, Internet infrastructure providers need to be able to host a wide diversity of custom solutions and applications.
Security and performance are two factors that need to be considered by Internet infrastructure providers when hosting software applications. Because many software applications may be hosted on one computer, it is often difficult to ensure the reliability of the applications. One bad software application can contain malicious code that can comprise system security. In addition, a poorly designed software application can degrade system performance and impact other software applications running on the host computer.
The present disclosure relates to a system and methods for hosting software application code on a local server and on remote servers in a secure and scalable manner.
According to one embodiment, a hosting system includes a local server, one or more remote servers, a configuration database and a content database. The local server includes a web front end module that processes client requests over the Internet to host application software on a server computer. The application software is typically customized to a user's business, for example a doctor's office, and uploaded to the local server over the Internet. Each remote server includes a back end module that manages the installation and operation of application software hosted on that server.
The local server uses the resources of the configuration database and the content database to determine on which server the application software should be hosted. The application software may be hosted on the local server or it may be hosted on one of the remote servers. The selection of the hosting server is done in a manner to make the overall hosting solution scalable and secure.
According to another embodiment, a method for hosting application software on a server is provided. When a request is received from a client computer to run application software on a server where the application software is being uploaded from the client to a local computer, the software application is validated. A determination of a performance tier for the software application is made, a determination of a solution type for the software application is made, and a determination of a topology of available host computers is made. Using the performance tier, solution type and topology information along with a load balancing algorithm, a determination is made as to a server, either local or remote, on which the software application should run. The operation of the software application is monitored as it runs on the server.
According to another embodiment, a method for requesting software applications to be hosted on a server is provided. A request is initiated with a local server to host an application program on a server. A software application program is uploaded to the local server where the software application program includes customized features specific to an application solution. A load balancing algorithm is uploaded to the local server, and the load balancing algorithm provides a method for determining the server on which the software application should be hosted. A validation mechanism is uploaded to the local server, and the validation mechanism provides a method of determining whether the software application should be hosted.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present disclosure, and together with the description serve to explain the principles of the disclosure. In the drawings:
The present application is directed to systems and methods for hosting software applications in a scalable and secure manner. Software applications are run on remote hosts that are tiered by solution type and performance. The software applications are run in a sandboxed environment that limits the ability of potentially malicious software from impacting the resources of the host computer and of other software applications running on the host computer.
In an example embodiment, the local servers 104 and remote servers 106 are part of an Internet based collaboration and document management system such as Microsoft Windows SharePoint Services (WSS). In another example embodiment, the local servers 104 and remote servers 106 are part of Microsoft Office. In another example embodiment, a local server 106 is a Microsoft SharePoint server. Other configurations are possible.
In example embodiments, a client 102 can be a personal computing device, such as a desktop or laptop computer, a personal data assistant, or a cellular telephone. A client 102 can include input/output devices, a central processing unit (“CPU”), a data storage device, and a network device. Typical input/output devices include keyboards, mice, displays, microphones, speakers, disk drives, CD-ROM drives, and flash drives. Computer readable media, such as the data storage device, provide for data retention. By way of example, computer readable media can include computer storage media and communication media. Computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. Among the plurality of information stored on the data storage device is a client operating system (“OS”) and client applications. The client OS is a program that manages the hardware and software resources of the client system. The client applications utilize the resources of a client 102 to directly perform tasks specified by the user. Other configurations for the clients 102 are possible.
When local server 202 processes the hosting request it makes a determination of where the software application should be hosted. This determination takes several factors into consideration. In a large scale system, thousands of applications may be hosted. Because many of these applications have the same solution type, it enhances system efficiency if applications with a common solution type are hosted together. It also improves system efficiency if a software application is not hosted on the local server that processes requests from clients. To this end and to improve system scalability, software applications may be hosted on remote servers like remote servers 204 and 206. It will be understood that in a large scale system there may be thousands of remote servers but in the example system of
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The load balancing module 506 uses one or more algorithms to assign software applications to hosts in an efficient and scalable manner. In one example embodiment, a load balancing algorithm is based on the frequency of use of a software application. In this example, the load balancing module 506 keeps track of incoming requests, storing the solution type and where the software application is assigned to be hosted. A calculation is made on frequency of requests for each solution type for a specified number of requests. So, for example, if over the last 10,000 requests, solution type A comprised 60% of these 10,000 requests, if a new request is received for solution type A, the software application for this request is mapped to host computers according to the same distribution of host computers as for the previous requests for solution type A. Thus, the new request is more likely to be directed to a host computer that already hosts other applications using solution type A.
In another example embodiment, a load balancing algorithm assigns software application solutions to performance tiers based on the cost of usage. For example, solutions with the worst performance characteristics, as measured by their previous usage of resources, are routed to the lowest performance tier. Software application solutions are assigned a usage penalty based on performance so that the worst performing solutions become too expensive to run. This “washing out” of poor performing solutions encourages overall system health. In addition, because poor performing solutions share a tier with other poor performing solutions, any disruptions to service (i.e. a solution which is terminated because of poor performance) is isolated to impacting other poor performing solutions.
The load balancing mechanism is extensible. Customers can provide their own load balancing algorithm, based on a generic template that can tailor the load balancing more specifically to their needs.
As an additional means to ensure scaling in the hosting system, solutions are also load balanced using a hashing algorithm. The hashing algorithm identifies solutions and the load balancing module routes them to server computers based on this hash. For example, if a software application to be hosted represents a solution already hosted on a server computer, the hashing algorithm prevents the same solution from being hosted on another server. This reduces the overhead of having the same software application hosted on two different host computers.
The resource monitoring module 604 monitors the resources used by software application solutions and determines whether resource quotas are exceeded. If a resource quota is exceeded, for example, if a solution uses more than its quota of memory, the solution is terminated. The use of resource monitoring in this manner is a proactive way to prevent system problems. For example, if a process goes into an infinite loop so that it continues to run, potentially for hours on end, the use of resource monitoring will terminate the process before overall system performance suffers and before system resources become depleted.
The assembly cache management module 608 manages the installation and running of custom software applications from a client. Assemblies are containers of custom code. In the assembly cache management module 608, a host service process manages the assemblies of custom code and manages how that code should be run on a server computer. The assembly cache management module 608 ensures that an assembly is loaded onto a remote server when needed and unloaded when not needed. In addition, a worker process manages the actual execution of that code.
The back end module 600 is run in a sandboxed environment, using an isolated infrastructure, to ensure that the software applications are run in a secure manner. The worker process is created with a restricted security token that limits access to system resources and to other software applications. In this manner, the system impact of malicious application code is limited.
Once the software application has been validated, the local host makes a determination of which server should host the application software. This is a multi-operation process. First, at operation 706 a performance tier is determined for the software application. From an efficiency standpoint, it is best to host similar performing software applications on the same server. In this way, a poor performing application will not impact a faster running application on the same server. Next, at operation 708 a solution type is determined for the software application. It is also efficient and improves scalability to group similar applications together. In addition, it is important to know if a software application to be hosted is already hosted on the system. One way to make this determination is via a hashing algorithm that determines a unique hash value for each software application. If a request is made to host an application that has already been hosted, the hash numbers will match, informing the local server that this application has already been hosted.
Next, at operation 710 the local server obtains topology information from a configuration database to determine which software applications are hosted on which remote servers. At operation 712, the local server uses the performance tier, solution type and topology information in conjunction with a load balancing algorithm to determine which remote server, should host the software application. The result of this determination is that similar solution types and similar performing applications are grouped together. At operation 714, a remote server is assigned to host the application software based on this determination. It is also possible, based on the determination, that the software application could be hosted on the local server instead of a remote server.
At operation 716, the application software is run, and at operation 718, the application software is monitored. Monitoring the application software comprises determining whether resource quotas assigned to the software are not being exceeded. If it is determined, that a resource quota is being exceeded, the software application is terminated.
Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.
