FYI: https://issues.jboss.org/browse/ISPN-2319
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Bela Ban Sent: Monday, September 17, 2012 2:42 AM To: [email protected] Subject: Re: [infinispan-dev] X-Site: Site Unreachable vs. Site Down I agree that there should be a configuration which determines after how many SITE-UNREACHABLE events (combined with a timeout), a site is declared as offline. (The count should be reset when there is a successful RPC to the remote site). Once a site is taken offline, then no RPCs would be sent to it, until it is taken online again (manually, by a sysadmin), and the state transfer has completed. Example: lon={A,B,C}, sfo={X,Y,Z}. - We're in London (lon), sfo acts as the backup site to lon - An RPC in lon includes A,B and SiteMaster(sfo) as targets - Before the RPC hits X, X crashes - JGroups retries X (a few times, timeout < "timeout" configured in <backup site=.../>) - Y takes over - JGroups re-routes the RPC to Y - The caller completes the RPC successfully - Now connectivity to sfo goes down - A caller in lon invokes an RPC on A,C and SiteMaster(sfo) - The call fails after 16s - Another RPC fails after 16s - After N failed RPCs, Infinispan in lon marks sfo as down (offline) - The next RPC has B and C as targets, but not SiteMaster(sfo) anymore, until sfo is brought online (manually) On 9/17/12 3:21 AM, Erik Salter wrote: > Hi all, > > For the X-Site pull request, Bela, Mircea and I had a design review. One of > the items that came up was the ability to mark a site as being "down" - > where a site has been unreachable for a period of time. This mostly applies > to the synchronous replication case where the backup failure policy has been > configured as "FAIL", i.e: > > <namedCache name="importantCache"> > <sites> > <backups> > > <backup site="NYC" strategy="SYNC" backupFailurePolicy="FAIL" timeout="16000 > 0"/> > </backups> > </sites> > </namedCache> > > The current implementation would be to fail all requests until a SA realizes > the site is offline and mark it through a JMX operation (provided in this > release?). Since I cannot afford a 100% failure rate until somebody gets > called, I think we need to take it a step further and add an element to mark > a site as offline after a period of time. (Note, though, a site can only > be brought back online manually.) > > Mircea talked about adding an element in the configuration for a custom > callback implementation. However, I think this is useful enough -- not only > for me -- but for other ISPN/JDG users as well. (Not to mention we can't > add configuration for callbacks) -- Bela Ban, JGroups lead (http://www.jgroups.org) _______________________________________________ infinispan-dev mailing list [email protected] https://lists.jboss.org/mailman/listinfo/infinispan-dev _______________________________________________ infinispan-dev mailing list [email protected] https://lists.jboss.org/mailman/listinfo/infinispan-dev
