Re: A way to initialize existing core

[Shawn Heisey <ap...@elyograg.org>]

On 3/28/2020 8:02 AM, Marius Ghita wrote:
> I'm running Solr inside a VM and I'm mounting the core folder when the VM
> boots up. However, if I destroy the VM and reinstall Solr, it won't
> recognize the previously created core. How can I tell Solr in an automated
> way to register the core?

When Solr starts, it navigates the entire solr home and tries to 
activate any cores that it locates there.  This is a process called 
"Core Discovery."

If Solr is running in cloud mode (with zookeeper), it compares the cores 
that it finds with the information in zookeeper.  If ZK database doesn't 
contain a collection referencing a core, the core will be deleted.  See 
this issue:

https://issues.apache.org/jira/browse/SOLR-13396

If you're not running in cloud mode, then there's no zookeeper and no 
central database to compare to, so Solr should not delete anything.

Thanks,
Shawn