Status hub used by autonomic application servers

Abstract

A method for serving applications including receiving a component status publication and acquiring a client request. The component status publication can specify a usage level for an application component. A server response for the client request can be selected from among a multitude of possible server responses based at least in part upon the component status publication. Each possible server response can differentially utilize application components. The client request can be response to by conveying the selected server response.

1 . An autonomic system for serving applications comprising:
 one or more computer systems having a plurality of application components, each application component automatically generating and conveying component usage messages after a predetermined time interval to a centralized location, receiving from said centralized location at least one component status publication generated based upon said component usage messages, each component usage message generated by a corresponding one of the plurality of application components and specifying activity information about the corresponding application component, said activity information specifying at least one of a number of users accessing the corresponding application component, a number of requests received by the corresponding application component within the predetermined time interval, and a rate at which resources of the corresponding application component are used, wherein said component status publication specifies a state of said at least one application component, wherein said centralized location determines the state based upon at least one of said component usage messages, wherein responsive to an overload condition, said centralized location adjusts the specified state of said application component in said component status publication from a steady-state to an overload-state, and wherein responsive to an end of said overload condition, said centralized location adjusts the specified state from the overload-state to the steady-state;   at least one application server configured to receive client requests for executing one or more computing tasks and select server responses to said client requests, wherein said computing tasks include at least one among a data processing task and a data management task, wherein the at least one application server is further configured to select server responses by
 determining that a server response to execute said computing tasks can be provided using either one of said external components or one of said local components, 
 comparing an usage level of said external component specified in said component status publication with a predetermined usage threshold value, and 
 if said usage threshold value is exceeded, using said local component to provide said server response for executing said computing tasks, otherwise using said external component to provide said server response for executing said computing tasks; and 
   a status hub configured to receive said component usage messages from at least one of said application components communicatively linked to said status hub and to responsively publish at least one component status publication to the at least application server, wherein each of said component status publications specifies a usage level for an associated one of said application components.   
   
   
       2 . The system of  claim 1 , wherein one of said usage levels indicates an overload state, and wherein said status hub is configured to provide at least one overload message whenever completion of said client request requires an application component that is in said overload state, and wherein said server response comprises-said overload message. 
   
   
       3  The system of  claim 1 , further comprising:
 an application component monitor configured to transmit component usage messages for an associated application component.   
   
   
       4 . The system of  claim 1 , wherein said application server is a multilayered application server configured to differentially provide said server responses to said client requests based at least in part upon said component status publications. 
   
   
       5 . The system of  claim 4 , wherein said multilayered application server comprises:
 an application layer containing a plurality of data methods, wherein at least a portion of said data methods utilize said application components.   
   
   
       6 . The system of  claim 4 , wherein said multilayered application server further comprises:
 a control layer configured to perform at least one action selected from the group comprising parsing parameters, checking input, fetching data objects, and calling methods.   
   
   
       7 . The system of  claim 4 , wherein said multilayered application server further comprises:
 a interface layer configured generate and format at least one electronic document containing said server response.   
   
   
       8 . A system for serving applications, the system comprising:
 one or more computer systems having:   means for receiving from a centralized location at least one component status publication generated based upon activity information specified in at least one component usage messages generated by at least one application component, each said component status publication specifying a usage level for the application component, wherein each said component usage message is generated after a predetermined period of time and is automatically delivered to the centralized location, wherein said component message specifies the activity information for the application component, and wherein the activity information specifies at least among a number of users accessing the corresponding application component, a number of requests received by the corresponding application component within the predetermined time interval, and a rate at which resources of the corresponding application component are used;   means for acquiring a client request to execute one or more computing tasks, wherein said computing tasks include at least one among a data processing task and a data management task;   means for selecting a server response for said client request from among a plurality of possible server responses to execute said computing tasks based at least in part upon said component status publications, wherein each possible server response differentially utilizes application components to execute said computing tasks, wherein means for selecting further comprise:
 means for determining that a server response to execute said computing tasks can be provided using either one of said external components or one of said local components; 
 means for comparing an usage level of said external component specified in said component status publication with a predetermined usage threshold value; and 
 if said usage threshold value is exceeded, using said local component to provide said server response for executing said computing tasks, otherwise using said external component to provide said server response for executing said computing tasks; and 
   means for responding to said client request with said selected server response;   wherein said component status publication specifies a state of said at least one application component, wherein said centralized location determines the state based upon at least one of said component usage messages, wherein responsive to an overload condition, said centralized location adjusts the specified state of said application component in said component status publication from a steady-state to an overload-state, and wherein responsive to an end of said overload condition, said centralized location adjusts the specified state from the overload-state to the steady-state.   
   
   
       9 . A machine-readable storage having stored thereon, a computer program having a plurality of code sections, said code sections executable by a machine for causing the machine to perform the steps of:
 receiving from a centralized location at least one component status publication generated based upon activity information specified in at least one component usage messages generated by at least one application component, each said component status publication specifying a usage level for the application component, wherein each said component usage message is generated after a predetermined period of time and is automatically delivered to the centralized location, wherein said component message specifies the activity information for the application component, and wherein the activity information specifies at least one among a number of users accessing the corresponding application component, a number of requests received by the corresponding application component within the predetermined time interval, and a rate at which resources of the corresponding application component are used, wherein said component status publication specifies a state of said at least one application component, wherein said centralized location determines the state based upon at least one of said component usage messages, wherein responsive to an overload condition, said centralized location adjusts the specified state of said application component in said component status publication from a steady-state to an overload-state, and wherein responsive to an end of said overload condition, said centralized location adjusts the specified state from the overload-state to the steady-state;   acquiring a client request to execute one or more computing tasks, wherein said computing tasks include at least one among a data processing task and a data management task;   selecting a server response for said client request from among a plurality of possible server responses to execute said computing tasks based at least in part upon said component status publications, wherein each possible server response differentially utilizes application components to execute said computing tasks, and wherein said selecting further comprises:
 determining that a server response to execute said computing tasks can be provided using either one of said external components or one of said local components; 
 comparing an usage level of said external component specified in said component status publication with a predetermined usage threshold value; and 
 if said usage threshold value is exceeded, using said local component to provide said server response for executing said computing tasks, otherwise using said external component to provide said server response for executing said computing tasks; and 
   responding to said client request with said selected server response.   
   
   
       10 . The machine-readable storage of  claim 9 , further comprising the step of registering each of said application components with the centralized location that publishes said component status publications. 
   
   
       11 . The machine-readable storage of  claim 9 , further comprising code sections executable by the machine for conveying said client request from a client browser through a proxy server. 
   
   
       12 . The machine-readable storage of  claim 11 , further comprising code sections executable by said machine for:
 receiving said client request and said at least one component status publication in a control layer;   calling from within said control layer a data method contained within an application layer; and,   activating at least one of said application components responsive to said calling step.   
   
   
       13 . The machine-readable storage of  claim 9 , said further comprising code sections executable by said machine for:
 identifying said plurality of server responses for said client requests;   for each of said server responses for executing said computing tasks, determining a required utilization for each application component that generates said server response;   comparing said required utilizations with available application component capacity, wherein said available application component capacity is determined at least in part from said component status publications; and,   selecting said server response based at least in part upon said comparing step.   
   
   
       14 . The machine-readable storage of  claim 9 , further comprising code sections executable by said machine for:
 if said application component is in said overload-state, selecting the server response that limits usage of said application components which triggered said overload condition.