Jini Discovery Utilities
JGDMS v3.0.0 Release Notes

Description

• net.jini.discovery.DiscoveryManagement
• net.jini.discovery.DiscoveryGroupManagement
• net.jini.discovery.DiscoveryLocatorManagement

The discovery utilities also include a set of standard helper utility classes that implement one or more of the discovery management interfaces. The helper utility classes are:

• net.jini.discovery.LookupDiscovery
• net.jini.discovery.LookupLocatorDiscovery
• net.jini.discovery.LookupDiscoveryManager

Additional classes and packages:

• net.jini.discovery.ConstrainableLookupLocator
• org.apache.river.discovery

The Jini Discovery Utilities Specification is available in html.

Changes since the v2.2.0 release

Changes since the v2.1.1 release

Changes since the v2.0.1 release

API additions and changes

Changes to the net.jini.discovery package.

• Parsing of the input URL and host name arguments in the corresponding ConstrainableLookupLocator and LookupLocator constructors has been made stricter; this may generate new MalformedURLExceptions. Note that the implementation does not conform to the DJ 3.0 specification, which requires parsing according to RFC 2396. The implementation is more permissive and allows characters such as '_' in host names to minimize backward incompatibility issues and anticipate compliance with RFC 3986 (which obsoletes RFC 2396).
• ConstrainableLookupLocator handles ConnectionAbsoluteTime and ConnectionRelativeTime constraints, enabling the specification of timeouts on unicast discovery connection attempts.
• LookupLocatorDiscovery handles any ConnectionRelativeTime and ConnectionAbsoluteTime constraints that may be set on the LookupLocators passed into its constructors.
• The LookupDiscovery, LookupLocator, ConstrainableLookupLocator, and LookupLocatorDiscovery classes now try all the IP addresses that a given host name may resolve to, instead of just the first one. This is as per the recommendations in RFC 1123.

Changes to the org.apache.river.discovery package.

• The Discovery class now enables constraint checking to be optionally delayed. With this change, constraint checks need not be performed as part of multicast announcement or request decoding. Discovery providers that support delayed constraint checking must implement the new MulticastAnnouncementDecoder and MulticastRequestDecoder interfaces.
• The DiscoveryConstraints class supports processing of ConnectionRelativeTime and ConnectionAbsoluteTime constraints. Note that the processed constraints will no longer return ConnectionRelativeTime and ConnectionAbsoluteTime ConnectionRelativeTime and ConnectionAbsoluteTime constraints. Note that the processed constraints will no longer return ConnectionRelativeTime and ConnectionAbsoluteTime as unfulfilled constraints.

Configuration

The current implementation of the LookupDiscovery utility now allows ConnectionRelativeTime and ConnectionAbsoluteTime as part of its discovery constraints.

Changes since the 1.1 release

The net.jini.discovery.LookupDiscovery and net.jini.discovery.LookupLocatorDiscovery utilities are now more multithreaded (BugID# 4346091 and 4397364)

Although the LookupDiscovery and the LookupLocatorDiscovery utilities primarily perform raw socket communication with the appropriate socket timeouts, the implementation of each utility previously employed a single thread to retrieve and unmarshal the lookup service proxies that were discovered. Furthermore, enhancements made to the LookupDiscovery utility for the 1.1 release of the Jini Technology Starter Kit (starter kit) resulted in additional remote calls being made in that utility's single thread of execution. Because there is no timeout control on network classloading, and because remote calls can take a very long time to complete (or even appear to hang), performing such calls in a single thread can greatly hinder the reliability and performance of either utility. As a result of this threat to reliability, and since it is not necessary for the remote calls to be performed sequentially in either the LookupDiscovery or the LookupLocatorDiscovery utility, the implementation of each utility was changed to employ multiple threads that perform the appropriate remote operations in parallel.

The net.jini.discovery.LookupDiscovery and net.jini.discovery.LookupDiscoveryManager utilities now provide multicast support for systems with multiple Network Interface Cards (BugID# 4425446)

Previously, when an entity employed either the LookupDiscovery or the LookupDiscoveryManager helper utility to participate in the multicast (group) discovery process, only a single name or IP address could be used to configure the system to send and receive multicast packets through the network interface card associated with the given name or address. Now, a list of names and/or addresses can be used to configure the system to send and receive multicast packets through any (or all) of the interfaces in the system.