I kicked off a separate thread for this as requested. On Tue, Jul 25, 2023 at 9:43 PM Pavel Tupitsyn <ptupit...@apache.org> wrote:
> > If the primary node 'comes back' after the primary node failure would > you expect the new value to propagate to all nodes? > > I don't think so, but I'm not 100% sure - could you ask about this > specific case in a separate thread? > > On Tue, Jul 25, 2023 at 8:50 AM Raymond Wilson <raymond_wil...@trimble.com> > wrote: > >> >> However, if a primary node fails before at least 1 backup >> node receives an update, then the update will be lost, and all nodes will >> have the old value. >> >> Does this imply that it is a good idea to have the FullSync write >> synchronization mode? If the primary node 'comes back' after the primary >> node failure would you expect the new value to propagate to all nodes? >> >> >> On Tue, Jul 25, 2023 at 5:22 PM Pavel Tupitsyn <ptupit...@apache.org> >> wrote: >> >>> > if a hard failure occurs to one of the backup servers in the >>> replicated cache will the server that failed have an inconsistent (old) >>> copy of that element in the replicated cache when it restarts >>> >>> If only a backup server fails and restarts, it will get new data from >>> the primary node, no issue here. >>> However, if a primary node fails before at least 1 backup node receives >>> an update, then the update will be lost, and all nodes will have the old >>> value. >>> >>> Related: CacheConfiguration.ReadFromBackup property is true by default, >>> meaning that with PrimarySync it is possible to get old value from a backup >>> node after an update, before backups receive new data. >>> >>> On Mon, Jul 24, 2023 at 11:51 PM Raymond Wilson < >>> raymond_wil...@trimble.com> wrote: >>> >>>> Hi Pavel, >>>> >>>> I understand the differences between the sync modes in terms of when >>>> the write returns. What I want to understand is if there are consistency >>>> risks with the PrimarySync versus FullSync modes. >>>> >>>> For example, if I have 4 nodes participating in the replicated cache >>>> (and am using the default PrimarySync mode), then the write will return >>>> once the primary node in the replicated cache has completed the write. At >>>> that point if a hard failure occurs to one of the backup servers in the >>>> replicated cache will the server that failed have an inconsistent (old) >>>> copy of that element in the replicated cache when it restarts? >>>> >>>> Raymond. >>>> >>>> >> >> -- >> <http://www.trimble.com/> >> Raymond Wilson >> Trimble Distinguished Engineer, Civil Construction Software (CCS) >> 11 Birmingham Drive | Christchurch, New Zealand >> raymond_wil...@trimble.com >> >> >> <https://worksos.trimble.com/?utm_source=Trimble&utm_medium=emailsign&utm_campaign=Launch> >> > -- <http://www.trimble.com/> Raymond Wilson Trimble Distinguished Engineer, Civil Construction Software (CCS) 11 Birmingham Drive | Christchurch, New Zealand raymond_wil...@trimble.com <https://worksos.trimble.com/?utm_source=Trimble&utm_medium=emailsign&utm_campaign=Launch>
