Hi Gus, given that OP said "...I copied the entire core over, conf and data directories." I assume he has a standalone solr instance.
On Thu, Sep 28, 2023 at 6:09 PM Gus Heck <gus.h...@gmail.com> wrote: > Scanned this thread, apologies if I missed something, but here's a few > thoughts: > > To get better advice make it clear if you are running Solr in Cloud mode > (a.k.a. self managed) or Legacy (a.k.a user managed). Some ways to know > which quickly: > > 1. Is there an associated Zookeeper cluster? If yes, then you are in > cloud mode if not then *probably* legacy (there's a way to run zookeeper > embedded, but that's not the normal setup). > 2. In the admin UI do you see the word 'Cloud' in the left navigation > bar? If yes, cloud, if no, legacy > > *Key concept: Solr is (normally) just a server providing access to an index > of your data. It allows you to find a link, or id for a "document" but does > not (normally) serve as a repository for your data.* > > This has some implications: > > 1. Solr is typically paired with one or more data repositories > (database, file system, sharepoint, etc) > 2. Solr normally cannot reindex data all by itself. Re-indexing is the > process of re-reading the repository, and creating a fresh index. > 3. Solr is just an index, and does not manage the process of reading the > data from sources (Exceptions like Data import handler[DIH] and > streaming > expressions exist, but DIH went away in 9.x and these are exceptions not > the rule) > 4. Typically *something* outside of solr sends documents to solr. > Re-indexing is normally the process of re-triggering something to send > the > documents again. > 5. This is unlike a database which contains both the data (the table) > and an index (PK/FK/index) of the data. > 6. Versus a database, Solr's benefit is that it is an index of the > *words* in the text of the document rather than entire string values. > > Thus (exceptional cases excluded) things you do to or in solr don't > "trigger reindexing". > > I have implied that sometimes solr can be the store for your data, which is > technically true. Unfortunately, this is tricky to get right, may > negatively impact performance, and results in long term data loss if done > wrong, so it's rarely recommended. I hope you haven't inherited this type > of problem! > > Upgrading Solr across a single minor version is often simple, but > occasionally requires work. Always read release notes and test the result > before going live. Upgrading across major versions is always work. Lucene > (and therefore solr) requires that you reindex data with each major > version. There are stopgap tools to allow an upgrade of an existing index, > but that is a temporary measure that only works for N to N+1 and you are > expected to re-index before N+2. > > - Gus > > -- > http://www.needhamsoftware.com (work) > https://a.co/d/b2sZLD9 (my fantasy fiction book) > -- Vincenzo D'Amore
