[hibernate-dev] Data encoding change for Hibernate OGM / Infinispan Embedded

To fix the sequence generation consistency issue on Infinispan Embedded [OGM-1212] I will need to change how sequences are encoded within the datagrid. This means OGM 5.2 will be able to read data as encoded by previous versions, but it will write data using a new format. This has some implications, such as people upgrading temporarily to OGM 5.2 can't go back to previous versions (without restoring a backup of the data). I will document this limitation. There's a second aspect: OGM will now include some code to be able to read pre-5.1 data, but eventually we'll want to remote this. How should we handle that? I'm thinking that people hitting this problem (in some future) will simply need to fetch OGM 5.2 and use that as an intermediate step; however OGM will only upgrade the data encoding "lazily" as it goes along: when something happens to be read, and happens to be re-written, it will re-encode it. But some data might never be rolled over to the new format. So I think we'll eventually need a data migration tool which performs all data-encoding aspects eagerly, so that it can report a point in time for which it's done and safe to move on to a future version. I don't wish to create such a tool now for OGM version 5.2 but I we should agree on a plan already. I also wonder if this should mark the following issue "out of date": - https://hibernate.atlassian.net/browse/OGM-1148 Thanks, Sanne