JGroups / News: Recent posts

see history.txt for details

Check out the files section for details

JavaGroups provides reliable group communication based on IP multicast and configurable protocol stack. This release includes a number of bug fixes and enhancements.

See http://sourceforge.net/project/shownotes.php?release_id=220870
for details.

Bela, March 1st 2004

The name was changed to JGroups, plus a new version 2.2 was created. The name change was made to avoid potential litigation (the name 'Java' is trademarked by SUN).
Bela Ban

This is just a snapshot for the last version of JavaGroups. The next releases will be under the new name of JGroups

• Aggressive pbcast.STABLE message garbage collection protocol to kick
  off collection when a certain number of bytes have been received (in
  addition to periodic collection)
• New protocol for multicast flow control (FC). Created PerfTest to
  test large number of messages with fc.xml
• New building block: DistributedQueue
• Diagnostics interface
• Various fixes to shun-reconnect sequence
• Added versioning to UDP and TCP. Message with different versions
  will be flagged (warning), but not discarded
• New suite of callRemoteMethods() methods in RpcDispatcher (e.g. using
  JMX style calling)
• New unicasting functionality: connect(null) creates a channel to a
  remote unicast receiver
• Beanshell (www.beanshell.org) protocol. Allows to inject Java code
  dynamically into a running stack
• New encryption protocol (ENCRYPT)
• Number of bug fixes

• Added FLOW_CONTROL protocol to throttle sender when receivers are
  lagging behind.
  (Ananda Jan 20 2003)

• Added ChannelClosedException and ChannelNotConnectedException to
  Channel.getState() and Channel.getStates()
  (bela Jan 20 2003)

• Various fixes related to the connect-disconnect-connect sequence:
  TUNNEL sends a null local address up the stack when disconnected,
  GossipClient provides a new timer and also cleans up the groups map
  when stopped, pbcast.NACKACK cleans up the NakReceiverWindows when
  disconnected and resets the seqno.
  (ovidiuf Jan 16 2003)

• Added capability to stuff additional data into an IpAddress. Use the CONFIG event to
  do this after channel creation but before connecting.
  IpAddress.getAdditionalData()/setAdditionalData() can be used to manage that data.
  This is useful e.g. when we want logical addresses rather than IpAddresses
  (bela Jan 14 2003)... read more

• Fixed serious Queue bug (affects RpcDispatcher, DistributedHashtable and other building blocks)
• ConnectionTable changes
• MessageDispatcher changes
• Other bug fixes

The Xerces JARs shipped with JavaGroups have been upgraded from 2.0.0 to 2.1.0. The reason is thet with JDK 1.3.X and xerces 2.0.0 there were segmentation faults. This wasn't a problem with JDK 1.4. With Xerces 2.1.0, both JDK 1.3 and 1.4 work okay.

• SMACK is a simple reliable multicast protocol, which does not require any group membership information
• FD_SIMPLE is a simple failure detection protocol. Can be used with SMACK
• smack.xml defines a protocol stack which uses SMACK, UNICAST and FD_SIMPLE for a lightweight reliable unicast and multicast protocol stack
• All files are available in the CVS only

• Stable version
• Features XML support for protocol stack definition
• Numerous bug fixed
• Performance enhancements
• Memory reduction

The JavaGroups website has a new look: point your browser to www.javagroups.com to check it out.
Thanks to the jakarta-site2 and Velocity folks for their great stuff !

AUTOCONF senses the network configuration and configures a protocol stack accordingly. This leads to fewer protocol stack misconfigurations.
Currently available only in the head CVS.

• Very useful replicated structure
• Tree-like structure, each node has a hashtable
• Every change is replicated to all members
• Building block: org.javagroups.blocks.ReplicatedTree
• Demo: org.javagroups.demos.ReplicatedTreeDemo

• New package structure, method names. Classes have been moved to the correct package
• Improved performance, some bug fixes
• For those who don't want to fetch the code from the CVS
• Some demos and tests won't work yet
• Existing applications have to be modified to compile (should be straightforward though)

The new User's Guide (Postscript, PDF and HTML) and the Javadoc documentation for JavaGroups-2.0 are now available at http://www.javagroups.com.
The next item will be the Programmer's Guide. Stay put....

Hey everybody,

I am pleased to announce that initial commit of Total order protocol
implementation based on "The Total Single-Ring Ordering and Membership
Protocol" http://citeseer.nj.nec.com/amir95totem.html is in cvs.

New classes are:

org.javagroups.protocols.TOTAL_TOKEN
org.javagroups.protocols.ring.*
org.javagroups.demos.TotalTokenDemo

Do please check it out , grind it etc etc

Thanks,
Vladimir & Mariya

First draft is available as Postscript and HTML at http://www.javaggroups.com

A first draft of the reorganization of JavaGroups has been submitted to the CVS. Changes include:
- New package and directory structure
- Changed all method names to start with lowercase
- Classes moved to correct package
==> Client code has to be changed to work with JavaGroups 2.0

Stable release of JavaGroups, a toolkit for reliable group communication. Finally contains the MERGE(2) protocol. Have fun and report bugs via the bug tracker.
Bela Ban

This is a quick-fix release for the severe NAKACK bug in 0.9.9.9. The best bet is to skip 0.9.9.9 and download 0.9.9.9.1 directly.

Contains additions, bug fixes and performance improvements since 0.9.9.5.

This version is contains a number of additions, bug fixes and performance improvements since version 0.9.9.5.

• Lots of bug fixes
• Performance improvement
• See history.txt for details

0.9.9.6:
- Added PERF/LOOPBACK protocols

0.9.9.7:
- New TOTAL protocol (by John Georgiadis)
- MERGE protocol (Gianluca Collot)

0.9.9.8:
- Added Trace module (by Jim Menard)
- Added PBCAST protocol
- Added FD_PID protocol (for PID-based failure detection)... read more

• Mostly bug fixes (converted all Thread.stop()/suspend()/resume() occurrences)
• Bug fixes for PBCAST
• New PARTITIONER protocol to simulate network partitions
• New NotificationBus class for publish/subscribe type notifications

Snapshot containing the PBCAST protocols (./protocols/pbcast) which makes JavaGroups more efficient and scalable in WANs. This code is experimental. If you want to use PBCAST, just change the protocol stack specification (see example in ./Demos/Draw.java).
There is some minimal documentation in ./Protocols/pbcast/{README, DESIGN}.