Abstract: Described are methods and systems for managing the connections between a client, an intermediary appliance and a server, so that asynchronous messages can be transmitted over HTTP from the server to a client. When a connection is established between a client and an intermediary, and the intermediary and a server to establish a logical client-server connection, that logical client-server connection is labeled and not maintained, while the connection between the client and the intermediary is maintained. Messages generated by the server and destined for the client are transmitted to the intermediary along with the connection label. The intermediary can then use the connection label to determine which client should receive the message.

Abstract: In a method and appliance for determining responsiveness of a service via a particular protocol, a device intermediary to a plurality of clients and a plurality of services determines response times from each of a plurality of services to respond to requests via a first type of protocol of a plurality of protocols. The device calculates an average response time for the first type of protocol from each of the response times of the plurality of services. The device establishes a predetermined threshold for which a response time of a service for the first type of protocol may deviate from the average response time. The device identifies a service as available responsive to determining that a deviation of the response time of the service from the average response falls within the predetermined threshold.

Abstract: The present application is related methods to monitor a state of one or more components of a remote access server farm by an intermediary to distinguish between operating and functional components and improve farm availability for user application requests. The intermediary may be deployed between a client and the remote access server farm and forwards client requests to functional components of the remote access server farm.

Abstract: The present invention provides a system and a method for global server load balancing of a plurality of sites based on a number of Secure Socket Layer Virtual Private Network (SSL VPN) users. The SSL VPN users may access servers at each of the plurality of sites. A global server load balancing virtual server (GSLB) may receive a request to access a server. The GSLB virtual server may load balance a plurality of sites wherein each of the plurality of sites may further comprising a load balancing virtual server load balancing users accessing the server accessing servers via an SSL VPN session. GSLB may receive from a first load balancing virtual server at a first site, a first number of current SSL VPN users accessing servers from the first site via SSL VPN sessions. The GSLB may also receive from a second load balancing virtual server at a second site, a second number of current SSL VPN users of the users accessing servers from the second site via SSL VPN sessions.

Abstract: The present invention provides systems and methods for maintaining site persistence in a hierarchical Global Server Load Balancing (GSLB) deployment. Via configuration of GSLB services locally and remotely on each of the GSLB appliances and LB appliances at a site, a site appliance identifies and associates requests from the GSLB with the site. Furthermore, the site appliance may receive a GSLB cookie with the client request and confirms the request is from the expected GSLB in the site hierarchy. When the load balancers receives a response from a server, the appliance may include the GSLB cookie with the response back to the client. The appliance may also include an LB cookie to identify the server selected by the LB. When the client sends another request, the request may include the GSLB and LB cookie. With this information, the GSLB and LB appliance may maintain site persistence for the client as well as server persistence at the site.

Abstract: The present solution provides a centralized configuration of a Global Server Load Balancing (GSLB) site hierarchy that may be batched across a plurality of appliances in a multi-site deployment. A single GSLB site hierarchy configuration may be distributed and operated on each appliance at each site. This reduces the configuration maintained for the multi-site deployment. Furthermore, in this manner, each appliance across multiple sites has an understanding of the entire topology of the multi-site deployment. Responsive to this configuration and understanding, each appliance may perform and optimize operations according to the site topology. For example, the appliances may selectively determine which sites to establish connections with in order to share metrics. In another example, appliances may select which remote sites to monitor services according to the topology.

Abstract: In a method and appliance for using a dynamic response time to determine responsiveness of one or more network services on a server, a monitor determines a response time for each of one or more network services. The monitor establishes an average response time based on the determined response time for each of the one or more network services. The monitor associates with the established average response time a predetermined threshold for which the response time of the one or more network services may deviate from the average response time and maintain an indication of responsiveness. The monitor monitors the response time of the one or more network services to one or more requests. The monitor determines that the response time of the one or more network services deviates from the average response time by the predetermined threshold. The monitor indicates that the one or more network services are unavailable.

Abstract: A method for enabling decentralized dynamic load balancing among a plurality of appliances providing access to a plurality of sites, each site comprising a local area network and at least one server includes: determining, by a first appliance, a first number of services currently available for access via a local area network connected to the first appliance; receiving, by the first appliance from a second appliance, a communication indicating a second number of services currently available for access via a local area network connected to the second appliance; receiving, by the first appliance, a plurality of requests to connect to a service; determining, by the first appliance, a weight to be assigned to the second appliance, wherein the determination is responsive to the second number; and forwarding, by the first appliance to the second appliance, a subset of the plurality of requests, wherein the number of requests comprising the subset is determined in response to the determined weight.

Abstract: The present application is related methods to monitor a state of one or more components of a remote access server farm by an intermediary to distinguish between operating and functional components and improve farm availability for user application requests. The intermediary may be deployed between a client and the remote access server farm and forwards client requests to functional components of the remote access server farm.

Abstract: The present invention provides methods and systems for performing load balancing via a plurality of virtual servers upon a failover using metrics from a backup virtual server. The methods and systems described herein provide systems and methods for an appliance detecting that a first virtual server of a plurality of virtual servers having one or more backup virtual servers load balanced by an appliance is not available, identifying at least a first backup virtual server of a one or more backup virtual servers of the first virtual server is available, maintaining a status of the first virtual server as available in response to the identification, obtaining one or more metrics from the first backup virtual server of a one or more backup virtual servers, and determining the load across the plurality of virtual servers using the metrics obtained from the first backup virtual server associated with the first virtual server.

Abstract: The present application is related methods to monitor a state of one or more components of a remote access server farm by an intermediary to distinguish between operating and functional components and improve farm availability for user application requests. The intermediary may be deployed between a client and the remote access server farm and forwards client requests to functional components of the remote access server farm.

Abstract: The present invention provides improvements to load balancing by providing a load balancing solution that distributes a load among a plurality of heterogenous devices, such as different types of local load balancers, using metrics collected from the different devices. The load balancing appliance collects metrics from heterogenous devices using a network management protocol and communication model, such as a Simple Network Management Protocol (SNMP). These heterogenous device metrics are available on the load balancing appliance with appliance determined metrics and metrics obtained by the appliance from homogenous devices using a metric exchange protocol. Via a configuration interface of the appliance, a user can select one or more of these different metrics for global load balancing. As such, the load balancing appliance described herein obtains a multitude of metrics from the different devices under management.

Abstract: The present invention provides improvements to load balancing by providing a load balancing solution that allows a user to select metrics, weights and thresholds from metrics collected or determined by a load balancing appliance as well as metrics obtained from another device, such as a server running the service. The systems and methods described providing a load balancing technique in which load balancing decisions can be made based on metrics known by another device monitoring such metrics. The load balancing appliance uses a network management protocol and communication model, such as a Simple Network Management Protocol (SNMP), to identify and collect metrics from a server, service or other device. These metrics are available on the load balancing appliance with appliance determined metrics. Via a configuration interface of the appliance, a user can select one or more appliance determined metrics and/or the metrics obtained via the network management protocol to determine the load of a service.

Abstract: In a method and appliance for using a dynamic response time to determine responsiveness of one or more network services on a server, a monitor determines a response time for each of one or more network services. The monitor establishes an average response time based on the determined response time for each of the one or more network services. The monitor associates with the established average response time a predetermined threshold for which the response time of the one or more network services may deviate from the average response time and maintain an indication of responsiveness. The monitor monitors the response time of the one or more network services to one or more requests. The monitor determines that the response time of the one or more network services deviates from the average response time by the predetermined threshold. The monitor indicates that the one or more network services are unavailable.

Abstract: A method for enabling decentralized dynamic load balancing among a plurality of appliances providing access to a plurality of sites, each site comprising a local area network and at least one server includes: determining, by a first appliance, a first number of services currently available for access via a local area network connected to the first appliance; receiving, by the first appliance from a second appliance, a communication indicating a second number of services currently available for access via a local area network connected to the second appliance; receiving, by the first appliance, a plurality of requests to connect to a service; determining, by the first appliance, a weight to be assigned to the second appliance, wherein the determination is responsive to the second number; and forwarding, by the first appliance to the second appliance, a subset of the plurality of requests, wherein the number of requests comprising the subset is determined in response to the determined weight.