Thank you for the suggestion. We do keep the original data around in an upstream database, so we are also able to reindex the data after the rollback, but I'm curious if there are ways to avoid the need to reindex for some time. We'll eventually start using the new codecs for sure, at which time we'll lose the ability to rollback without reindex anyways, but ideally I'd like to make that a separate step from the Lucene upgrade, and possibly apply the codec upgrade gradually per index.
Best regards, Yixun Xu On Fri, Jun 23, 2023 at 8:19 PM Steven Schlansker < stevenschlans...@gmail.com> wrote: > Hi, > > > On Jun 23, 2023, at 2:34 PM, Yixun Xu <yix...@gmail.com> wrote: > > > > Hello, > > > > I have a service that creates and manages Lucene indices. The service is > > using Lucene 8 and I want to upgrade to Lucene 9, and I would like to be > > able to rollback the upgrade in case I encounter any issues (*). The > > problem is that the older version of the service won't be able to read > the > > segments created after the upgrade because they would be created using > > Lucene 9's codec. > > > > One potential solution is to keep writing new indices using Lucene 8's > > codecs after upgrading to Lucene 9, and only start using Lucene 9's codec > > after some time. However this doesn't seem to be officially supported: > the > > lucene-backward-codecs package provides older codecs, but they are > > read-only. > > > > My questions are: > > 1. I can try copying over the actual codecs from Lucene 8 instead of > using > > lucene-backward-codecs, but is this actually supposed to work, or will > > there be undefined behaviors when the codec is used with Lucene 9? > > 2. Is there an alternative solution to support rollbacks? > > This is probably not the solution you are looking for, but the way we > manage this is to > have a higher level logical version (including Lucene codes, > backwards-incompatible document format changes, etc). > We read all indexing operations off of a Kafka topic, and each index > format version independently keeps Kafka offsets. > So, after upgrading to index format X+1, rolling back to index format X > will also rewind the Kafka consumers and they > will replay any missed indexing operations immediately. > > > > > Any help would be greatly appreciated! > > > > Best regards, > > Yixun Xu > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > For additional commands, e-mail: java-user-h...@lucene.apache.org > >
