Abstract: A monitoring system for virtual application environments comprising: at least one physical machine executing a first operating system; at least one virtual machine operating on at least one of the at least one physical machines, each such virtual machine operating a second operating system; and an agent program operating on each of the at least one physical machines, where, each agent program is operable to obtain a first set of metrics from the first operating system, such first set of metrics including metrics in respect of each virtual machine as viewed by the first operating system, and operable to connect to the second operating system of each virtual machine hosted on the physical machine the agent program operates on and obtain a second set of metrics in respect of the virtual machine from the second operating system, the agent program further operable to communicate the first and second sets of metrics to a manager program.

Abstract: An improved root-cause approach to problem diagnosis in data networks in the form of a method comprising the steps of: associating each metric in a at least one set of metrics with at least one component and/or network device; obtaining values for each such metric from a monitoring system; determining whether each such metric is indicative of a problem within the data network; and ranking and correlating indicative problems to determine whether a problem may be symptomatic of another problem based on an interconnection and/or interdependency between a physical machine and a virtual machine, between components or between components and network devices.

Abstract: An improved root-cause approach to problem diagnosis in data networks in the form of a method comprising the steps of: associating each metric in a at least one set of metrics with at least one component and/or network device; obtaining values for each such metric from a monitoring system; determining whether each such metric is indicative of a problem within the data network; and ranking and correlating indicative problems to determine whether a problem may be symptomatic of another problem based on an interconnection and/or interdependency between a physical machine and a virtual machine, between components or between components and network devices.

Abstract: A monitoring system for virtual application environments comprising: at least one physical machine executing a first operating system; at least one virtual machine operating on at least one of the at least one physical machines, each such virtual machine operating a second operating system; and an agent program operating on each of the at least one physical machines, where, each agent program is operable to obtain a first set of metrics from the first operating system, such first set of metrics including metrics in respect of each virtual machine as viewed by the first operating system, and operable to connect to the second operating system of each virtual machine hosted on the physical machine the agent program operates on and obtain a second set of metrics in respect of the virtual machine from the second operating system, the agent program further operable to communicate the first and second sets of metrics to a manager program.

Abstract: A data service system includes a server system. The server system includes a request processor that schedules external requests to be serviced by the server system based on classification information contained in a tag of each of the requests. An application system is coupled to the server system. The application system includes an application engine that performs a transaction requested by an external request and provides response to the request to the server system. The application system also includes a business rule engine that stores business rules regarding classification for various transactions. The business rule engine also uses the business rules to analyze the response to the request. A tag generator is provided in the application system that generates the tag based on the analysis of the business rule engine.

Abstract: An adaptive admission control system for a server application system includes a request queue that stores incoming requests. A discard queue is provided to store requests to be discarded. An actuator is coupled to the request queue and the discard queue to determine the input rate of requests during a previous processing cycle. A controller is coupled to the actuator and the request queue to determine a target number of requests to be sent to the request queue during the next processing cycle based on the difference between the actual and desired queue occupancy of the request queue. The controller sends the target number to the actuator. The actuator sends the target number of requests to the request queue either from the listen queue or from the listen queue and the discard queue based on the input rate of requests from the listen queue.

Abstract: A TCP/IP-based application system includes an application module that performs predetermined functions based on external requests received from an external queue. The external queue is external to the application system and stores the external requests before the requests are fetched into the application system. A network interaction module is coupled to the application module and the external queue (1) to fetch the external requests from the external queue into the application system and (2) to determine which, if any, of the fetched requests will not be processed by the application module based on the processing capacity of the application module and the rate of the external requests arriving at the external queue such that when the application module is overloaded, TCP timeouts for requests stored in the external queue are minimized and the chance of those requests stored in the external queue from being dropped is also minimized.

Abstract: An acceptor for admitting incoming requests to a server application includes a session manager that determines the class of an incoming request. The class includes a first class and a second class. A queuing module is provided to store the request if the incoming request is of the second class. A priority control module is provided to ensure that a predetermined number of requests are sent to the server application for service in each cycle. The priority control module allows (1) the predetermined number of the first class requests to be sent to the server application if the first class requests received in a cycle are at least equal to the predetermined number, and (2) a mixture of the first class requests and the second class requests to be sent to the server application if the first class requests received in a cycle are less than the predetermined number. A method of handling incoming requests to the server application is also described.

Abstract: A method of monitoring a data network includes storing topology information that identifies interconnections and interdependencies among network components, as well as links between websites and the components. Each component is also mapped to relevant protocol layers of a hierarchy of protocol layers that are ranked according to dependencies among the protocol layers in implementing functions. Network test measurements are also mapped to the appropriate protocol layers. Based upon the topology information and the various forms of mapping information, a user is able to navigate through a web-based user interface to determine root causes of network problems. Alternatively, an automated correlation process may be used to prioritize alerts of network problems, so that the root cause can be more easily ascertained.

Abstract: A method of monitoring a data network includes storing topology information that identifies interconnections and interdependencies among network components, as well as links between websites and the components. Each component is also mapped to relevant protocol layers of a hierarchy of protocol layers that are ranked according to dependencies among the protocol layers in implementing functions. Network test measurements are also mapped to the appropriate protocol layers. Based upon the topology information and the various forms of mapping information, a user is able to navigate through a web-based user interface to determine root causes of network problems. Alternatively, an automated correlation process may be used to prioritize alerts of network problems, so that the root cause can be more easily ascertained.

Abstract: A method and system of modeling a selected service within a network environment includes forming a service model template that is not specific to the network environment, but identifies anticipated network elements and network services that cooperate to enable the selected service. The service model template includes specifications related to linking the anticipated network elements and network services. When the service model template is combined with discovered instance information that is specific to actual network elements and actual network services, a service model instance is generated for the selected service. The service model instance includes identifications of dependencies among the elements and services. Preferably, the service model instance also includes identification of the “health” of the different elements and services.

Abstract: A method for identifying services, service elements and dependencies among the services and service elements includes executing first and second phases of discovery. In the first phase, the services and service elements are detected, as well as a first set of dependencies. The second phase is based on results of the first phase and is focused upon detecting inter-service dependencies, i.e., conditions in which proper operation of one service relies upon at least one other service. Various techniques may be used in executing the first phase, including accessing information in a domain name service (DNS) of the network to identify dependencies, as well as services and service elements. Discovery within the first phase may also be based upon recognizing naming conventions. Regarding the second phase, one approach to discovering inter-service dependencies is to deploy discovery agents implemented in computer software to access content of configuration files of applications detected in the first phase.

Abstract: A method and system for modeling services available via a network include selecting a core service that is to be modeled, forming a discovery template that is specific to the selected core service, and automatically discovering the elements which cooperate to provide the core service. The discovery template includes instructions for implementing automated techniques for discovering service elements, and preferably services, which are anticipated as being cooperative in executing the core service. The system includes a number of discovery modules for generating outputs indicative of the services and service elements. A discovery engine is responsive to the discovery template to invoke the modules that are identified in the template as being relevant to discovering specified services and service elements. The template also identifies dependencies among the modules, so that the proper sequence of processing can be determined.

Abstract: The dependancies of a computer service are modeled. The modeling hierarchically defines the relationships between the computer service and the hardware and software services which the computer service depends. These relationships may be contained in data structures defining a directed acyclic graph. The model also defines which measurements need to be taken to determine health and performance of the computer service and the health and performance of all the computer services upon which the computer service depends. Software agents that take these measurements may be deployed using the model to determine the measurement locations and functions. Data from measurement agents may be propagated up the model hierarchy. The model may also be visualized by a graphical interface to communicate the dependancies and the health and status of the services upon which the modeled service depends.

Abstract: A scheme of evaluating performance of a network connecting a remote terminal to a data service system is described. The scheme emulates a communication protocol to transfer data reliably and in sequence with congestion control. The communication protocol includes mechanisms for acknowledgment and retransmission and a dynamic window size. The scheme restricts the dynamic window size not to be greater than a predetermined maximum window size, and the amount of data transferred to a predetermined data transfer size, thereby accurately measuring user-perceived network throughput without significantly impacting network performance.

Abstract: A scheme is described for a data service system having a number of modules. Some of the modules are interdependent. To measure the status of an individual module, the scheme first collects measurements from a number of measurement routes that involve the module. Then the scheme analyzes the interdependencies of the measurements to determine the status of the individual module. The scheme may also determine status of the data service system with a minimal number of measurement routes. This is done by determining (1) all possible measurement routes, (2) determining the dependency between the modules and the measurement routes, and (3) analyzing the dependency to select minimal number of the measurement routes. The scheme can diagnose whether a module is a problematic module or not by analyzing a number of measurements that involve the module. If one of the measurements is good, the module is identified as non-problematic.

Abstract: A diagnostic system for a data access networked system (e.g., an Internet/Intranet access networked system) is described. The data access networked system includes a number of data service systems coupled together. Each of the data service systems is independently administrated. The diagnostic system includes a number of diagnostic modules, each running a number of diagnostic tests within one of the data service systems upon receiving a diagnostic request. The diagnostic modules also transmit the diagnostic request and diagnostic results to one another using an open standard communication protocol. The diagnostic system also includes a diagnostic terminal that is coupled to a first diagnostic module of the diagnostic modules to generate the diagnostic request to the first diagnostic module and to display the diagnostic results received from the first diagnostic module. A diagnostic system for a data service system of a data access networked system is also described.

Abstract: A method and system of monitoring throughput of a data access system includes logging each transfer of data from a content server to a remote site, with each log entry including information indicative of transfer size, date, times, source and destination. The method includes accessing the log information in a passive and non-intrusive manner to evaluate the performance of transfers to a selected subset of the remote sites. In another embodiment, the performance evaluation is implemented for system resource allocation planning. In the preferred embodiment, the data access system is a broadband data system and the content servers utilize Internet applications. Also in the preferred embodiment, the data throughput is measured by the transfer rate of useful data, rather than all data including retransmissions.

Abstract: An admission control scheme for real-time traffic requests in communication networks is disclosed. The scheme monitors tile performance of each link and predicts the traffic guarantees that can be offered when certain dummy traffic (pseudo traffic) mimicking the behavior of real-time streams is added to the existing traffic. When an application requests connection to the network, it specifies a Quality of Service (QoS) bound that it desires. A routing subsystem of tile network makes use of the predicted values while attempting to find a path over which tile application's QoS bound requirement will be satisfied. After the route is chosen, connection setup will involve verifying at each node along the route whether sufficient resources exist to support tile new connection. This explicit verification is likely to be necessary because the routing subsystem does not normally have up-to-date global state information.