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The Oracle Tuxedo CORBA Notification Service supports two application programming interfaces. One is based on the CORBA-based Notification Service as defined by the CORBAservices: Common Object Services Specification. This interface is referred to in this document as the CosNotification Service interface. The other interface, called the Oracle Simple Events interface, is an Oracle proprietary interface designed as an easier to use alternative.To determine the persistence of the subscription and whether or not events delivery is retried following a failed delivery, subscribers specify a Quality of Service (QoS). There are two Quality of Service settings: persistent and transient Quality of Service (QoS). The QoS is a property of the subscription.The subscription is in effect until a failed event delivery is detected. On detection of a failed delivery, the subscription is terminated. Normally, the Notification Service, for performance reasons, does not check whether it successfully delivered an event to a transient subscriber. However, occasionally, when the Notification Service delivers an event to a transient subscriber, it checks whether or not the event was successfully delivered. If it was not successfully delivered and the CORBA::TRANSIENT exception is not returned, the Notification Service assumes that the subscription has gone away and cancels the subscription. If the Notification Service receives the CORBA::TRANSIENT exception when an attempt to deliver fails, it assumes that the subscriber is busy and discards the event, but it does not cancel the subscription.Notification Service applications use the Bootstrap object to obtain an object reference to the event channel factory. This is done by using the Tobj_Bootstrap::resolve_initial_references operation. The Bootstrap object supports two service IDs for Notification Service applications, NotificationService and Tobj_SimpleEventsService. The NotificationService object is used in applications that use the CosNotification Service API. The Tobj_SimpleEventsService object is used in applications that use the Oracle SimpleEvents API.
type_name=””
event_name=””
variable_header=empty
Filterable_data=(content of the FML buffer)The subscription_name must not exceed 128 characters in length.Same parameter as the domain_type field in the Fixed Header portion of a structured event, as defined by the CORBA-based Notification Service specification. This field is a string that is used to identify a particular vertical industry domain in which the event type is defined, for example, “Telecommunications”, “Finance”, and “Health Care”. Because this parameter is a regular expression, you can also use it to set domain patterns on which to filter. For example, to subscribe to all domains that begin with the letter F, set the domain to “F.*”. For information on how to construct regular expressions, see the recomp command in the Oracle Tuxedo ATMI C Function Reference.Same parameter as the type_name field in the Fixed Header portion of a structure event, as defined in the CORBA-based Notification Service specification. It is a string that categorizes the type of event, uniquely within the domain, for example, Comm_alarm, StockQuote, and VitalSigns. Because this parameter is a regular expression, you can also use it to set event type patterns on which to filter. For example, to subscribe to all event types that begin with the letter F, you would set the type to “F.*”. For information on how to construct regular expressions, see the recomp command in the Oracle Tuxedo ATMI C Function Reference.This parameter defines the data that the subscription must match in Boolean expressions. The following data types are supported: short, long, char, float, double, and string. Table 2‑2 lists the Boolean expression operators that are supported.
{
void push_structured_event(
in CosNotification::StructuredEvent event);For a description of the parameters supported by this operation, see “Parameters Used When Creating Subscriptions” on page -11.Indicates one of the following problems:
Tobj_Events::SUB_INVALID_FILTER_EXPRESSION
Tobj_Events::SUB_UNSUPPORTED_QOS_VALUEIndicates one of the following problems:
Tobj_Events::SUB_DOMAIN_BEGINS_WITH_SYSEV
{
interface Filter {
ConstraintInfoSeq add_constraints (
in ConstraintExpSeq constraint)
raises (InvalidConstraint);Indicates the following problem: Tobj_Events::SUB_INVALID_FILTER_EXPRESSION.
{
interface FilterFactory {
Filter create_filter (
in string constraint_grammar)
raises (InvalidGrammar);
destroy();
};
}; //CosNotifyFilterIndicates the constraint_grammar is not supported.Used in the subscriber application to create a new filter object. This filter is used to determine which events are delivered to a subscription. The subscriber must set up the filter and add it to the proxy within five minutes; otherwise, the filter will be destroyed. The filter grammar must be set to Tobj_Notification::Constraint_grammar; otherwise, the InvalidGrammar exception is raised.
in CosNotifyComm::StructuredPushConsumer push_consumer)
raises(CosEventChannelAdmin::AlreadyConnected,
CosEventChannelAdmin::TypeError );
};
// The following operations are inherited.
void set_qos(in QoSProperties qos)
raises (UnsupportedQoS);
FilterID add_filter (in Filter new_filter );
Filter get_filter( in FilterID filter )
raises ( FilterNotFound);
void disconnect_structured_push_supplier();
readonly attribute ProxyType MyType;
};
}; //CosNotifyChannelAdminvoid connect_structured_push_consumer (
in CosNotifyComm::StructuredPushConsumer push_consumer)
raises(CosEventChannelAdmin::AlreadyConnected,
CosEventChannelAdmin::TypeError );Indicates that the connect_structured_push_consumer operation has already been invoked.
in CosNotifyComm::StructuredPushSupplier push_supplier)
raises(CosEventChannelAdmin::AlreadyConnected);
// The following operations are inherited.
readonly attribute MyType;
void push_structured_event(
in CosNotification::StructuredEvent notification )
raises( CosEventComm::Disconnected );
void disconnect_structured_push_consumer();
};
}; \\StructuredProxyPushConsumervoid connect_structured_push_supplier (
in CosNotifyComm::StructuredPushSupplier push_supplier)
raises(CosEventChannelAdmin::AlreadyConnected);
a. The Priority in the variable header section of the event, if specified, must be short value in the range of 1 to 100.
b. If event filterable data filtering (versus filtering on domain and type only) is required, or if events are to be received by an Oracle Tuxedo subscriber, then additional restrictions apply. See “Structured Event Fields, Types, and Filters” on page -5 and “Interoperability with Oracle Tuxedo Applications” on page -9.
{
interface ConsumerAdmin :ProxySupplier obtain_notification_push_supplier (
in ClientType ctype,
out ProxyID proxy_id)
raises ( AdminLimitExceeded )};
}; //CosNotifyChannelAdminProxySupplier obtain_notification_push_supplier (
in ClientType ctype,
out ProxyID proxy_id)
raises ( AdminLimitExceeded )Used when subscribing. This operation is used in subscriber applications to create proxy push supplier objects. Only structured events are supported (that is, ANY_EVENT and SEQUENCE_EVENT ClientTypes are not supported). Therefore, the ClientType input parameter must be set to CosNotifyComm::STRUCTURED_EVENT. If you shut down and restart the subscriber and subscription survives more than one run of your program, the ProxyID returned by this operation should be durably stored. The subscriber must narrow the proxy supplier to CosNotifyChannelAdmin::StructuredProxyPushSupplier. All required operations must be completed in five minutes.
{
interface SupplierAdmin :
CosNotification::QoSAdmin,
CosNotifyComm::NotifyPublish,
CosNotifyFilter::FilterAdmin,
CosEventChannelAdmin::SupplierAdmin {ProxyConsumer obtain_notification_push_consumer (
in ClientType ctype,
out ProxyID proxy_id)
raises ( AdminLimitExceeded );
};
}; //SupplierAdminProxyConsumer obtain_notification_push_consumer (
in ClientType ctype,
out ProxyID proxy_id)
raises ( AdminLimitExceeded );Used when posting events. This operation is used in poster applications to create proxy push consumer objects. ClientType must be set to “CosNotifyChannelAdmin::STRUCTURED_EVENT”. The ProxyID returned should be ignored. The Proxy Consumer must be narrowed the proxy supplier to CosNotifyChannelAdmin::StructuredProxyPushConsumer.
{
interface EventChannel :
CosNotification::QoSAdmin,
CosNotification::AdminPropertiesAdmin,
CosEventChannelAdmin::EventChannel {readonly attribute ConsumerAdmin default_consumer_admin;
readonly attribute SupplierAdmin default_supplier_admin;
readonly attribute CosNotifyFilter::FilterFactory
default_filter_factory;
};
}; //CosNotifyChannelAdmin
{
interface EventChannelFactory {
EventChannel get_event_channel ( in ChannelID id )
raises (ChannelNotFound);
};
}; //CosNotifyChannelAdminUsed when subscribing, unsubscribing, and posting events. This operation is used in applications to get the EventChannel object. When subscribing, the EventChannel object is used to get the filter factory object and the ConsumerAdmin object. When unsubscribing, the EventChannel object is used to get the ConsumerAdmin object.When posting an event, the EventChannel object is used to get the SupplierAdmin object. The ChannelID parameter that is passed in must be set to Tobj_Notification::DEFAULT_CHANNEL; otherwise, the ChannelNotFound exception is raised.
{
interface StructuredPushConsumer : NotifyPublish {void push_structured_event(
in CosNotification::StructuredEvent event)
raises(CosEventComm::Disconnected);
void disconnect_structured_push_consumer:
//The following operations are inherited.
void offer_change(
in CosNotification::EventTypeSeq added,
in CosNotification::EventTypeSeq removed )
raises ( InvalidEventType );
};
}; //CosNotifyCommvoid push_structured_event(
in CosNotification::StructuredEvent event)
raises(CosEventComm::Disconnected);CosEventComm::Disconnected
push_structured_event
DEFAULT_CHANNEL.
SUBSCRIPTION_TYPE.
TRANSIENT_SUBSCRIPTION or Tobj_SimpleEvents::
PERSISTENT_SUBSCRIPTION.
SUBSCRIPTION_TYPE and the value is Tobj_Notification::
TRANSIENT_SUBSCRIPTION or Tobj_Notification::
PERSISTENT_SUBSCRIPTION.
consumer can raise this exception since a user can create the proxy, then use the ntsadmin utility to delete the subscription, and then call connect_structured_push_
consumer on the proxy.
