SENSE Architecture & Specification: Glossary

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Appendix D: Glossary

This section contains concise definitions of SENSE terminology.

Under construction: the following list is neither complete nor entirely consistent.

APIApplication Programming Interface; commonly used to refer to either the specification or set of library modules used by a Client application to communicate with a Server.
Attention ConditionCondition of a Publication in which the Publication is unable to perform its intended mission until the cause of the alert condition is eliminated.
Attention MessageAn Event Message declaring that the Publication has entered the Attention Condition, or that a new Attention Event has occurred while the Publication is in the Attention Condition.
CancelTerminate subscription to the specified Publications.
CapabilityA specific feature performed by a Server, Publisher or Subscriber; a capability is indicated by the presence of a specific property, the value of which specifies the level of capability. For example, if a Server is able to persistently store Publications, then it would define the property "PersistentPublications" and set the value to "Yes".
ClientAn application consuming the services of a Server.
Client ContextAn API element used within a Client application to manage a single session with a Server.
ConditionThe overall operational status of a Publication, one of a small, finite set of enumerated values. Condition includes several properties, including at least a numeric description, a text description, and a time stamp indicating when the Condition last changed.
Client APIThe API used by all Clients to register with the Server and to perform operations as a Publisher, Subscriber, or Manager.
Client ContextAn API element used within a Client application to manage a single session with a Server.
EditionA specific form of a Publication. Editions may differ because they describe Event information in different data syntaxes or because they include specific subsets of Event information for a Publication.
EntityThe abstract source of Events represented by a Publication.
EventA collection of information submitted by a Publisher on behalf of an associated Publication. A Subscriber receives Events after it has subscribed to the Publication.
Event MessageA message used to convey the occurrence and content of an Event. A Publisher sends Event Messages to a Server on behalf of the associated Publication, whereupon the Server sends the Event Message (with enhancements) to all current Subscribers of the Publication.
Event ProtocolThe format and content of a series of messages that convey event information between two parties; examples might include SNMP, IEEE 1284.1 (TIPSI), CPAP, etc.
Event Protocol GroupA set of event protocols that are related in the name hierarchy in that they share all but the last atom of their names. See Property Group.
Healthy ConditionA condition indicating that the Publication is operationally consistent and able to perform its intended mission.
Idle ConditionA condition in which the Publication is operationally consistent, but currently not performing any useful work in its intended mission.
Info MessageA message containing arbitrary informative data, such as debugging information, etc.
MessageA protocol element exchanged between a Client and a Server.
Message IdAn unsigned 32-bit integer used by the message sender to uniquely identify the message.
Nak MessageA message indicating that the previously sent message can not be processed as desired; the reason for failure is contained in the message.
NameAn string used to denote a specific Value.
NameListAn unordered list of Names.
NegotiationThe mechanism used to resolve registration properties when a Server and a Client may have different desires or policies; a Client submits the desired value, and the Server responds with the value that must be used during the session.
OperatorA person designated to perform certain types of operational tasks for an Entity.
Persistent PublicationA Publication that persists across instantiations of a SENSE Server, for example, across power cycles.
Persistent StateDenotes a state that will not change unless further action is taken.
PropertyAn object attribute represented by a Name/Value pair. In SENSE, both the name and the value are represented as text strings.
Property GroupA set of Properties that are related in the name hierarchy by sharing all but the last atom of their names.
Property ListAn unordered list of Properties.
Property SheetThe complete set of Properties of an object.
PublicationThe representation of an Entity as managed by a Publisher.
Publication IdThe unique Server-assigned identifier for a single Publication.
PublisherThe agent acting on behalf of an Entity to publish Events that occur within the Entity. A Publisher registers with the Server as a Client.
Publisher IdThe unique Server-assigned identifier for a specific Publisher.
RegistrationA formal relationship between a Client and a Server, where the Client requrests access to the Server and supplies identifying information the the Server.
Registration PeriodThe time during which a Client Session is active; once the period expires, the Session is no longer exists and all communications with the Client ceases.
RenewalThe mechanism used by a Client to extend the life of a Session.
Reply MessageA message used to respond to a previously received request. All Reply messages have as a Message Id the same Id specified in the original request message.
ServerThe agent providing SENSE services to Clients.
SessionThe time during which a Client is registered with a Server; a Session commences upon successful registration with the Server, and ends when the Client either deregisters with the Server, or the registration period expires.
SubscribeThe mechanism used by a Subscriber to begin receiving Event Messages from a Publication.
SubscriberA Client interested in Events from a Publication.
SubscriptionThe mechanism used to manage the relationship between one or more Publications and a single Subscriber.
Subscription IdThe unique Server-assigned identifier for a single Subscription.
TechnicianA person assigned certain operational and repair tasks that require a relatively high level of training.
Transient ClientA Client that has not yet registered with a Server. A transient Client is limited by the Server to a few exploratory operations, such as "Enumerate Publications."
Transient ConditionA situation that is very short-lived, one that does not require further action to change.
Unknown ConditionA condition indicating that the current status of an Publication is not currently known.
ValueA string representing context-specific information.
Warning ConditionA condition indicating that the Publication currently has one or more situations which, if not corrected in the relatively near future, will probably cause the Publication to enter the Attention Condition.