Despite deleting all the docs, what I suspect is that you still have segments that have no live docs in them, but still preserve the 6x marker.
That said, what’s the point of the 7.7.2 step? Why not just index once into a pristine 8.4.1 cluster? You could even do this on a few machines, serving no traffic, and when you were satisfied repurpose your current machines by installing Solr 8.4.1 on them and using ADDREPLICA to build out your cluster. Oh, and I strongly recommend that you do _not_ simply change the LuceneMatchVersion and reuse your current config. Please start with a new configset and port just the changes from your 6x config to them. Best, Erick > On Feb 27, 2020, at 8:02 AM, Pavel Polivka <ppoli...@idc.com> wrote: > > Hello, > > I am doing upgrade of SolrCloud cluster from 6.5.0 to 8.4.1. > > My process is: > > Upgrade to 7.7.2. > Reconfigure my solrconfig to have > <luceneMatchVersion>7.7.2</luceneMatchVersion>, reload collections. > Delete all docs in all collections and index them again. > > Upgrade to 8.4.1. > This step always fails for me with message in logs saying that the index > format is probably created by 6.x version. > My thinking is that the reindex I do in 7.7.2 is not enough. > > Is there a way to check in what format my index is? > > Any ideas if I am doing anything wrong? > > > Thanks. > > > Pavel Polivka
