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Chapter 4 Adapter Service Options : Overview

Overview
TIBCO ActiveMatrix Adapter for Tuxedo supports publication, subscription, request-response, and request-response invocation services.
After configuring an adapter instance, select the adapter instance, then click Adapter Services. Add one or more services to the adapter instance by dragging and dropping a Publication Service, Subscription Service, Request-Response Service or Request-Response Invocation Service icon from the palette panel to the design palette.
Message Transports
The transport type (Rendezvous or JMS) you select for the runtime adapter determines which quality of service, delivery mode, connection factory type, and wire format the service can use.
Quality of Service
This is the level of service that determines how messages are sent.
Possible values are:
(TIBCO Rendezvous transport type only) Reliable message delivery. Ensures that each multicast or broadcast message is received as long as the physical network and packet recipients are working, and that the loss of a message is detected. This choice can compensate for brief network failures because it can retransmit a message on request if the first attempt failed. This choice is appropriate when message delivery is expected but some loss can be tolerated. Messages are received without explicit confirmation.
(TIBCO Rendezvous transport type only) Certified message delivery. Offers stronger assurances of message receipt, along with tighter control, greater flexibility and fine-grained reporting. Guarantees that every certified message reaches its intended recipient in the order sent. The message can be sent across network boundaries, and if a network fails, delivery attempts continue until delivery succeeds or until the message's time limit expires.
If certified message delivery is used, data is stored in a ledger file. The size of the ledger depends on several factors, the most important of which is the retention rate of stored data. That is, the ledger grows fastest in response to the cumulative length of undeliverable messages. You must ensure that sufficient disk space is available for the expected size of the ledger.
(TIBCO Rendezvous transport type only) A distributed queue is a group of cooperating transport objects, each in a separate process. To obtain load balancing among servers, the adapter uses distributed queues for one-of-n delivery of messages to a group of servers. Each member of a distributed queue listens for the same subject using the TIBCO Rendezvous Distributed Queue listener objects. Even though many members listen for each inbound message (or task), only one member processes the message. For details on distributed queues, see TIBCO Rendezvous Concepts.
This option is no longer supported. The option is only included for backward compatibility.
Delivery Mode
(JMS transport type only) The method of delivery for a JMS message. The semantics for these fields are somewhat more complex than the explanation given here. See TIBCO Enterprise Message Service User’s Guide for more information.
In general, a message marked persistent will be available to a JMS client even if the TIBCO Enterprise Message Service server goes down. Persistent messages are held in secondary storage in the server and have guaranteed delivery when sent to a topic that has durable subscribers. (If a topic has no durable subscribers, there are no subscribers that need messages resent in the event of a server failure and therefore messages do not need to be saved.) Performance is improved because disk I/O is not required.
(JMS transport type only) A message marked non persistent will not be available to a JMS client if the TIBCO Enterprise Message Service server goes down. These messages are never written to persistent storage.
Indicates that the service is registered with the EMS server. Messages sent to a durable Subscription Service are held by the EMS server until they are consumed by the service. The service can be down and expect to receive its messages when it comes back up.
Indicates that the service is not registered with the EMS server. Messages sent to a non-durable Subscription Service are not held by the EMS server. If the service is down, it will not receive the messages that arrived at the EMS server while the service was down.
Connection Factory Type
(JMS transport type only) The JMS mode of transport supports the following messaging protocols (TIBCO Enterprise Message Service must be installed to use the JMS transport):
A message published to a topic is broadcast to one or more subscribers. All messages published to the topic are received by all services that have subscribed to the topic. This type of message protocol is also known as broadcast messaging because messages are sent over the network and received by all interested subscribers. This messaging model is known as publish-subscribe.
A message sent to a queue is consumed by one receiver. Each message has only one receiver though multiple receivers may connect to the queue. The first receiver to access the queue receives the message and the other receivers do not. A queue retains all messages sent until a certain time the messages are consumed or expired. This message protocol is known as point-to-point.
Wire Formats
Services must use the same wire format to exchange data.
A self-describing wire format used by TIBCO Rendezvous applications. Control information for validation is not sent in the message. If you use this format, the adapter is compatible with adapters not developed with TIBCO Adapter SDK.
The XML Message wire format conforms to specifically constructed and fully compliant XML Schema (XSD) based on the existing definition of the TIBCO ActiveEnterprise schema.
An externally-described XML wire format supported by the TIBCO Adapter SDK. Control information for validation is sent in the message. If no control information is included, an exception is returned to the subscriber. TIBCO ActiveEnterprise standard wire format provides class information and packing rules for the TIBCO Adapter SDK set of data types. This format allows TIBCO ActiveEnterprise components to perform extra validation on messages sent or received.
See the TIBCO Adapter SDK Programmer’s Guide for details about the control information generated and sent with TIBCO ActiveEnterprise messages.

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