Hi Anthony, That's an option but, as you say, the cost in infrastructure is high and there are also other problems to solve like how to do the switch between systems and how to assure the data consistency among them.
I was thinking that in many cases it might be possible to support a rolling downgrade similar to the rolling upgrade given that the rolling upgrade already allows the coexistence of old and new members in a cluster. -Alberto On 23/9/19 15:55, Anthony Baker wrote: > Have you considered using a blue / green deployment approach? It provides > more flexibility for these scenarios though the infrastructure cost is high. > > Anthony > > >> On Sep 23, 2019, at 5:59 AM, Alberto Gomez <alberto.go...@est.tech> wrote: >> >> Hi, >> >> Looking at the Geode documentation I have not found any reference to >> rolling back a Geode upgrade. >> >> Running some tests, I have observed that once a Geode System has been >> upgraded to a later version, it is not possible to rollback the upgrade >> even if no data modifications have been done after the upgrade. >> >> The system protects itself in several places: gfsh does not allow you to >> connect to a newer version of Geode, the Oplog files store the version >> of the server which prevents an older server to start from a file from a >> newer server, the cluster also does not allow older members to join a >> cluster with newer members and there are probably other protections I >> did not hit. >> >> Even if you tamper with some of those protections, you can run into >> trouble due to compatibility issues. I ran into one when I lifted up the >> requirement to have the same gfsh versions using versions 1.8 and 1.10 >> because it seems there is some configuration exchanged in Json format >> whose format has changed between those two versions. >> >> My question is that if it has ever been considered to support rollback >> of Geode upgrades (preferably in rolling mode), at least between systems >> under the same major version. In our experience customers often require >> the rollback of upgrades. >> >> Thanks in advance for your help, >> >> -Alberto G. >>
