JavaGroups, the underlying group management and communication protocol of clustering, should be guarding against lost or duplicate messages.
Checkout the docs available at www.javagroups.com XXXXXXXXXXXXXXXX Bill Burke Chief Architect JBoss Group, LLC XXXXXXXXXXXXXXXX > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of David Klimek > Sent: Monday, March 24, 2003 11:55 AM > To: [EMAIL PROTECTED] > Cc: [EMAIL PROTECTED] > Subject: Re: [JBoss-user] time synchronization in cluster (ClusterTimer > Service) > > > Hello, > > thank you all for answering my questions. To achieve something very > close to global cluster clock, I'v decided to implement Clustered Timer > service with the same interface as javax.management.timer.Timer. > > Features: > - each added notification will be distributed on each node running > Clustered Time service > - listeners can register for notification on each node running Clustered > Timer service > - only Clustered master replica can notify listeners, if so all listener > on all cluster nodes will be notified > - Timer service ensures that Notifications Id are unique in cluster > > There is problem how this service should behave when partition merge > occurs. It is possible that before merge both partitions has the same > Notification Id for differend Notifications but some Notifications can > be created before cluster was split into paritions and so they are > identical. So simple merge or concat. of Notifications will result in > either lost or duplicate Notifications. > > Have you got any idea how this can be clearly solved? > > > Thank's > > David > > > > Tom Gardner wrote: > > There is no such thing as global time, only an approximation to > > it seen from one viewpoint. If you depend on their being a > > single global definition of time then your application will, > > sooner or later, have failures due to race conditions. > > > > Your preconditions can be beneficially relaxed by > > - specifying whether "to the nearest h/s/ms/us/ns" > > is sufficiently close > > - ensuring all the operations are independent > > - ensuring opreations' order is not significant. > > > > To clarify your problem, consider what might happen > > if you had two JVMs running on the same CPU. > > > > > >>Hello, > >> > >>I need to be sure that each replica of my clustered application will do > >>specific operation at the same real time (eg at 9:34am). > >> > >>I see two solutions: > >> > >>a) Keep computers clock synchronized > >> >> Does jboss provide such service or is this OS/administrator issue? > >> > >>b) Cluster TickTock service > >>Will run on each cluster node, one node will be master and in required > >>time will call method tickTock() on all nodes > >> >> Is this functionality now available in JBoss? > >> > >>c) Is there other solution? > >> > >>Thank's > >>David > >> > >> > >>-- > >>http://www.sweb.cz/david.klimek > >> > >> > >> > >>------------------------------------------------------- > >>This SF.net email is sponsored by: Tablet PC. > >>Does your code think in ink? You could win a Tablet PC. > >>Get a free Tablet PC hat just for playing. What are you waiting for? > >>http://ads.sourceforge.net/cgi-bin/redirect.pl?micr5043en > >>_______________________________________________ > >>JBoss-user mailing list > >>[EMAIL PROTECTED] > >>https://lists.sourceforge.net/lists/listinfo/jboss-user > >> > > > > > > > > > > ------------------------------------------------------- > > This SF.net email is sponsored by: Tablet PC. > > Does your code think in ink? You could win a Tablet PC. > > Get a free Tablet PC hat just for playing. What are you waiting for? > > http://ads.sourceforge.net/cgi-bin/redirect.pl?micr5043en > > _______________________________________________ > > JBoss-user mailing list > > [EMAIL PROTECTED] > > https://lists.sourceforge.net/lists/listinfo/jboss-user > > > > > > > > -- > http://www.sweb.cz/david.klimek > > > > ------------------------------------------------------- > This sf.net email is sponsored by:ThinkGeek > Welcome to geek heaven. > http://thinkgeek.com/sf > _______________________________________________ > JBoss-user mailing list > [EMAIL PROTECTED] > https://lists.sourceforge.net/lists/listinfo/jboss-user ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf _______________________________________________ JBoss-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/jboss-user
