Glossary
administered objects
Administered objects are preconfigured JMS (or C#) objects that a Broker administrator creates for use with client programs. Administered objects are stored in a standardized namespace called the Java Naming and Directory Interface (JNDI), and can be managed with administrative tools or programmatically. There are two types of administered objects: connection factories and destinations.
authentication
The process by which the system validates a user's logon information. The credentials (user name and password) are compared to an authorization list. If a match occurs, authorization is granted to the extent available for the user in the permissions list.
Broker
A part of the Broker Server process, providing services such as receiving, queueing, and delivering events. One or more Brokers can exist on a Broker Server. Each Broker can have any number of document types, client groups, and clients associated with it; they also share process and storage space with other Brokers. Brokers can be added to or leave territories. See also territory.
Broker Server
The core product of the webMethods Broker communication system that runs Brokers. Broker Servers are the delivery and administration hubs of document-based computing. Broker Servers can have multiple Brokers that share the same process and storage space.
certificate
The public key of a private/public key pair that has been signed by a Certification Authority. See also Certification Authority.
Certification Authority
An entity that issues certificates, usually with an authentication server. The webMethods Broker uses trusted root certificates so that a live connection to a Certification Authority to verify certificates is unnecessary.
CLASSPATH
The environment variable that tells the Java compiler where to look for the classes it needs. -classpath is an option to the Java interpreter and the Java compiler that tells them (while compiling or running) where to look for a class. -classpath overrides CLASSPATH.
client group
A Broker client group defines certain properties for all clients belonging to that group, including a client's publish and subscribe permissions to specific document types.
cluster
A cluster is a group of Brokers functioning as a single logical Broker. All Brokers in a cluster maintain the same set of document types and client groups.
connection
An active connection from a JMS or C# client to webMethods Broker.
connection factory
An administered object that a JMS or C# client uses to create a connection with webMethods Broker. A connection factory encapsulates the set of configuration parameters defined for a connection.
The type of connection factory determines whether a connection is made to a topic (in a publish-subscribe application) or a queue (in a point-to-point application), and whether messages are available for management by a distributed transaction coordinator on an application server (XATopicConnectionFactory and XAQueueConnectionFactory).
C# clients can only use a generic connection factory (ConnectionFactory) to establish a connection.
container
An entity that provides services such as security, life cycle management, and run-time services to components. Types of containers include servlets, applets, and application clients.
destination
A destination is an administered object that a client uses to specify the target of messages it produces and the source of messages it consumes. Destinations specify the identity of a destination to a JMS or C# API method. There are four types of destinations: queue, topic, temporaryQueue, and temporaryTopic.
distinguished name
A certificate needs a distinguished name to identify the issuer of the certificate. A distinguished name consists of one or more of the following components:
CN, OU, O, EM, L, ST, C
where CN is the common name, OU the organizational unit, O the organization, EM the e-mail address, L the locality, ST the state or province, and C the country from where the certificate was issued.
distributed transaction
In the messaging domain, a distributed transaction is a transaction where resources from other applications are modified as a result of one or more messages being consumed, as part of a single commit operation. For JMS applications managed by an application server, you use XA-based connection factories in the context of a distributed transaction.
DSA
Digital Signature Algorithm (DSA) is part of the Digital Signature Standard (DSS), selected to be the digital authentication standard of the U.S. Government. DSA is intended for authentication only.
durable subscription
A durable subscription allows subscribers to receive all the messages published on a topic, including those published while the subscriber is inactive. Making a subscription durable provides the reliability of queues to the publish/subscribe style of messaging.
event
A generic message exchanged by resources. The generic nature of events makes possible universal tools that operate on all kinds of events.
initial context
An object on the client that provides access to the JNDI provider and connects to the namespace in which the administered objects are stored.
keystore
A storage location for an SSL certificate. A keystore does not store trusted roots; these are kept in a trust store.
Lightweight Directory Access Protocol (LDAP)
A standard protocol for accessing information in a directory. LDAP defines processes by which clients can connect to an X.500-compliant or LDAP-compliant directory service. Provided the clients have sufficient access rights, they can add, delete, modify, or search for information.
local transaction
A transaction that is handled within the context of a session, and includes any sends and receives within the session. This type of transaction cannot include updates to external resources such as databases. A local transaction does not use the XA-based connection factories
message consumer
A message consumer receives messages from a topic or queue to which it has subscribed. Programmatically, a message consumer is an object (created by a session) that is used for receiving messages sent to a destination.
message listener
An asynchronous event handler for messages.
message producer
A JMS or C# client that produces messages. Programmatically, a message producer is an object (created by a session) that is used to send messages to a destination (a topic or a queue).
message selector
Allows a JMS or C# client to filter the messages it wants to receive by use of a SQL expression in the message header. The expression is applied to a property in the message header containing the value to be filtered Only messages whose property values match the selector (that is, evaluate to a Boolean value of true) are received by the message consumer.
nonpersistent message
A message that has no guarantee of being saved if a failure occurs and the session ends.
persistent message
A message that will be saved if the connection is lost.
Point-to-Point (PTP) messaging
One-to-one delivery of messages. Messages are exchanged between clients through named message queues. A message producer sends a message to a named queue. A message receiver, which subscribes to the queue, receives the message.
publish/subscribe messaging
One-to-many delivery of messages. Messages are exchanged between clients through publishing and subscribing to named topics. A message publisher sends messages to a named topic, and every subscriber to the topic can retrieve the messages.
rollback
A way of ending a transaction whereby all the messages composing the transaction are discarded and updates to any resources included in the transaction are reversed. Typically, any messages included in the transaction are sent again after a rollback.
session
A session object is a single-threaded context for producing and consuming messages. A session can create and service multiple message producers and consumers.
shared state
The process of distributing the processing of topics to multiple clients, possibly executing on different hosts. This process provides a basic form of load balancing. Shared state is enabled when multiple JMS client connections to the webMethods Broker used as a JMS provider share the same connection client ID.
subscriber
In the publish-subscribe messaging model, a subscriber is a client that registers interest in receiving a message. There are two types of subscribers:
Durable. These subscribers receive all the messages published on a topic, including those published while the subscriber is inactive
Non-durable. These subscribers receive messages on their chosen topic only if the messages are published while the subscriber is active.
territory
A set of Brokers that share information about their document type definitions and client groups. Brokers within the same territory have knowledge of one another's document type definitions and client groups. Events can travel from clients on one Broker to clients on another Broker in the same territory.
time to live (TTL)
Length of time in milliseconds that the message system retains a produced message.
topic
A specific type of message that is published by a message producer and subscribed to by an interested message subscriber.
transaction
An atomic unit of work that modifies data. Transactions can be local or distributed. Distributed transactions require use of the XA-based interfaces.
trust store
A storage location for the SSL certificates, or trusted roots, of one or more Certification Authorities (CAs). The webMethods Broker uses trusted roots to verify certificates
trusted root
A special certificate issued by a well known and trusted Certification Authority. Trusted roots are used to validate the authenticity of certificates received by a client or server application, and are saved in a special file called a trust store.