>> 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>
