Notification Service 1

Notification Service

Outline Notification Service Event Service vs Notification Service Example

Notification Service 2

Shortcomings of Event Services

No filtering: all notifications sent to an event channel will be forwarded to all consumers

No Concept of QoS: client cannot configure channels for their specific requirements

No information about required or supplied notifications: consumer doesn’t know about existing suppliers and the types of events they offer; vice versa

Unstructured event data: event data is wrapped into instances of the generic type Any

Notification Service 3

Notification Service Architecture

Text book: figure 11.7

Notification Service 4

Notification Service vs Event Service

Event types Notification Service supports typed, any, structured and sequence of structured

events Event service only supports typed and any type event

Admin interface Notification service allows multiple consumer admin interface and supplier

admin interface Event service only support single admin interface (ConsumerAdmin,

SupplierAdmin)

Channel creation Notification service defines a standard factory interface for event channels to

allow clients to retrieve channels Event service does not have the factory interface

Notification Service 5

Structured Event

domain_name

type_name

event_name

name value

name value

name value

name value

name value

…

…

remainder_of_body

Event Header

Event Body

Fixed Header

Variable Header

Filterable BodyFields

Remaining Body

Notification Service 6

QoS Properties

EventReliability and ConnectionReliability 0: best effort 1: persistent, retransmit after recover

Priority Default 0, could be positive, or negtive

StartTime, StopTime, Timeout MaxEventsPerConsumer OrderPrority DiscardPolicy MaximumBatchSize PacingInterval Text book Figure 11.9

Notification Service 7

Filters

CosNotifyFilter::Filter Decide when to forward the event consumer

CosNotifyFilter::MappingFilter Affact how the QoS values are treated Priority Lifetime For consumer only (ConsumerAdmin, or SupplierProxy)

Notification Service 8

CosNotifyChannelAdmin:Event Channel

interface EventChannel : CosNotification::QoSAdmin, CosNotification::AdminPropertiesAdmin, CosEventChannelAdmin::EventChannel

{readonly attribute EventChannelFactory MyFactory;readonly attribute ConsumerAdmin default_consumer_admin;readonly attribute SupplierAdmin default_supplier_admin;readonly attribute CosNotifyFilter::FilterFactory default_filter_factory;

ConsumerAdmin new_for_consumers( in InterFilterGroupOperator op, out AdminID id );

SupplierAdmin new_for_suppliers( in InterFilterGroupOperator op, out AdminID id );

ConsumerAdmin get_consumeradmin ( in AdminID id ) raises (AdminNotFound);

SupplierAdmin get_supplieradmin ( in AdminID id ) raises (AdminNotFound);

AdminIDSeq get_all_consumeradmins();

AdminIDSeq get_all_supplieradmins();

}; // EventChannel

Notification Service 9

CosNotifyChannelAdmin:ConsumerAdmin

interface ConsumerAdmin : CosNotification::QoSAdmin, CosNotifyComm::NotifySubscribe, CosNotifyFilter::FilterAdmin, CosEventChannelAdmin::ConsumerAdmin { readonly attribute AdminID MyID;

readonly attribute EventChannel MyChannel;readonly attribute InterFilterGroupOperator MyOperator;attribute CosNotifyFilter::MappingFilter priority_filter;attribute CosNotifyFilter::MappingFilter lifetime_filter;readonly attribute ProxyIDSeq pull_suppliers;readonly attribute ProxyIDSeq push_suppliers;

ProxySupplier get_proxy_supplier ( in ProxyID proxy_id ) raises ( ProxyNotFound );

ProxySupplier obtain_notification_pull_supplier ( in ClientType ctype, out ProxyID proxy_id) raises ( AdminLimitExceeded );

ProxySupplier obtain_notification_push_supplier ( in ClientType ctype, out ProxyID proxy_id) raises ( AdminLimitExceeded );

void destroy(); }; // ConsumerAdmin

Notification Service 10

CosNotifyChannelAdmin:SupplierAdmin

interface SupplierAdmin : CosNotification::QoSAdmin, CosNotifyComm::NotifyPublish, CosNotifyFilter::FilterAdmin, CosEventChannelAdmin::SupplierAdmin {

readonly attribute AdminID MyID;readonly attribute EventChannel MyChannel;readonly attribute InterFilterGroupOperator MyOperator;readonly attribute ProxyIDSeq pull_consumers;readonly attribute ProxyIDSeq push_consumers;

ProxyConsumer get_proxy_consumer ( in ProxyID proxy_id ) raises ( ProxyNotFound );

ProxyConsumer obtain_notification_pull_consumer ( in ClientType ctype, out ProxyID proxy_id) raises ( AdminLimitExceeded );

ProxyConsumer obtain_notification_push_consumer ( in ClientType ctype, out ProxyID proxy_id) raises ( AdminLimitExceeded );

void destroy();

}; // SupplierAdmin

Notification Service 11

CosNotifyChannelAdmin:Event Channel Factory

interface EventChannelFactory {

EventChannel create_channel ( in CosNotification::QoSProperties initial_qos, in CosNotification::AdminProperties initial_admin, out ChannelID id) raises(CosNotification::UnsupportedQoS,

CosNotification::UnsupportedAdmin );

ChannelIDSeq get_all_channels();

EventChannel get_event_channel ( in ChannelID id ) raises (ChannelNotFound);

}; // EventChannelFactory

Notification Service 12

CosNotifyFilter:FilterAdmin interface FilterAdmin {

FilterID add_filter ( in Filter new_filter );

void remove_filter ( in FilterID filter ) raises ( FilterNotFound );

Filter get_filter ( in FilterID filter ) raises ( FilterNotFound );

FilterIDSeq get_all_filters();

void remove_all_filters();

}; // FilterAdmin

Notification Service 13

CosNotifyFilter:Filter interface Filter {

readonly attribute string constraint_grammar;

ConstraintInfoSeq add_constraints ( in ConstraintExpSeq constraint_list) raises (InvalidConstraint);

void modify_constraints ( in ConstraintIDSeq del_list, in ConstraintInfoSeq modify_list) raises (InvalidConstraint, ConstraintNotFound);

ConstraintInfoSeq get_constraints( in ConstraintIDSeq id_list) raises (ConstraintNotFound);

ConstraintInfoSeq get_all_constraints();void remove_all_constraints();void destroy();boolean match ( in any filterable_data ) raises (UnsupportedFilterableData);boolean match_structured ( in CosNotification::StructuredEvent filterable_data )

raises (UnsupportedFilterableData);boolean match_typed ( in CosNotification::PropertySeq filterable_data )

raises (UnsupportedFilterableData);CallbackID attach_callback ( in CosNotifyComm::NotifySubscribe callback);void detach_callback ( in CallbackID callback) raises ( CallbackNotFound );CallbackIDSeq get_callbacks();

}; // Filter

Notification Service 14

CosNotifyFilter:FilterFactory interface FilterFactory {

Filter create_filter ( in string constraint_grammar) raises (InvalidGrammar);

MappingFilter create_mapping_filter ( in string constraint_grammar, in any default_value)

raises(InvalidGrammar);

}; // FilterFactory

Notification Service 15

CosNotificationmodule CosNotification { typedef string Istring; typedef Istring PropertyName; typedef any PropertyValue;

struct Property { PropertyName name; PropertyValue value; }; typedef sequence<Property> PropertySeq; typedef PropertySeq OptionalHeaderFields; typedef PropertySeq FilterableEventBody; typedef PropertySeq QoSProperties; typedef PropertySeq AdminProperties;

struct EventType{ string domain_name; string type_name; }; typedef sequence<EventType> EventTypeSeq;};

Notification Service 16

CosNotificationmodule CosNotification {

struct FixedEventHeader { EventType event_type; string event_name; };

struct EventHeader { FixedEventHeader fixed_header; OptionalHeaderFields variable_header; };

struct StructuredEvent { EventHeader header; FilterableEventBody filterable_data; any remainder_of_body;

};

typedef sequence<StructuredEvent> EventBatch;

};

Notification Service 17

QoS Adminmodule CosNotification { interface QoSAdmin { QoSProperties get_qos(); void set_qos ( in QoSProperties qos) raises ( UnsupportedQoS ); void validate_qos (

in QoSProperties required_qos, out NamedPropertyRangeSeq available_qos )

raises ( UnsupportedQoS ); }; // QosAdmin

const string MaxQueueLength = "MaxQueueLength"; const string MaxConsumers = "MaxConsumers"; const string MaxSuppliers = "MaxSuppliers"; const string RejectNewEvents = "RejectNewEvents";};

Notification Service 18

AdminPropertiesAdminmodule CosNotification { interface AdminPropertiesAdmin {

AdminProperties get_admin();void set_admin (in AdminProperties admin) raises ( UnsupportedAdmin ); };

}; // CosNotification

Notification Service 19

Notification Interface

module CosNotifyComm {exception InvalidEventType { CosNotification::EventType type; };interface NotifyPublish { void offer_change (

in CosNotification::EventTypeSeq added, in CosNotification::EventTypeSeq removed )

raises ( InvalidEventType ); }; // NotifyPublishinterface NotifySubscribe { void subscription_change(

in CosNotification::EventTypeSeq added, in CosNotification::EventTypeSeq removed )

raises ( InvalidEventType ); }; // NotifySubscribe};

Notification Service 20

Consumer and Supplier

module CosNotifyComm {interface PushConsumer : NotifyPublish, CosEventComm::PushConsumer

{ }; // PushConsumer

interface PullConsumer : NotifyPublish, CosEventComm::PullConsumer { }; // PullConsumer

interface PullSupplier : NotifySubscribe, CosEventComm::PullSupplier { }; // PullSupplier

interface PushSupplier : NotifySubscribe, CosEventComm::PushSupplier { };};

Notification Service 21

Structured Consumer

module CosNotifyComm {interface StructuredPushConsumer : NotifyPublish { void push_structured_event( in CosNotification::StructuredEvent notification) raises(CosEventComm::Disconnected);

void disconnect_structured_push_consumer(); }; // StructuredPushConsumer

interface StructuredPullConsumer : NotifyPublish { void disconnect_structured_pull_consumer(); }; // StructuredPullConsumer};

Notification Service 22

Structured Supplier

module CosNotifyComm {interface StructuredPullSupplier : NotifySubscribe { CosNotification::StructuredEvent pull_structured_event() raises(CosEventComm::Disconnected); CosNotification::StructuredEvent try_pull_structured_event(

out boolean has_event) raises(CosEventComm::Disconnected); void disconnect_structured_pull_supplier(); }; // StructuredPullSupplier

interface StructuredPushSupplier : NotifySubscribe { void disconnect_structured_push_supplier();}; // StructuredPushSupplier

};

Notification Service 23

Sequence Consumer

module CosNotifyComm {interface SequencePushConsumer : NotifyPublish { void push_structured_events(

in CosNotification::EventBatch notifications) raises(CosEventComm::Disconnected); void disconnect_sequence_push_consumer(); }; // SequencePushConsumer

interface SequencePullConsumer : NotifyPublish { void disconnect_sequence_pull_consumer(); }; // SequencePullConsumer};

Notification Service 24

Sequence Supplier

module CosNotifyComm {interface SequencePullSupplier : NotifySubscribe {

CosNotification::EventBatch pull_structured_events( in long max_number ) raises(CosEventComm::Disconnected); CosNotification::EventBatch try_pull_structured_events(

in long max_number, out boolean has_event) raises(CosEventComm::Disconnected); void disconnect_sequence_pull_supplier(); }; // SequencePullSupplier

interface SequencePushSupplier : NotifySubscribe {void disconnect_sequence_push_supplier();

}; // SequencePushSupplier

};