Easiest way is just to copy the entire directory that contains core.properties to the second Solr's SOLR_HOME directory (I'd have the Solr instanced down). The core discovery Shawn mentioned just recursively descends from SOLR_HOME and whenever it encounters a core.properties figures out that this is a core and loads it. So you have some directory like blah/core1 that has core.properties in it. Just move core1 to SOLR_HOME for solr2.
But this really seems like an XY problem. What do you hope to gain by this? Why not just create a new core on Solr2 and start using that? Or do you have a lot of cores on this machine and are just balancing the number of them? In the latter case, why not just use SolrCloud and ADDREPLICA/DELETEREPLICA to move cores around? Best, Erick On Wed, Sep 13, 2017 at 6:09 AM, Shawn Heisey <apa...@elyograg.org> wrote: > On 9/12/2017 11:27 AM, Shashank Pedamallu wrote: >> I wanted to know how does Solr pick up cores on startup. Basically, what I >> would like to try is Read cores created from one Solr instance from another >> Solr instance. i.e., >> >> * I will have 2 Solr Instances SOLR1, SOLR2. Only SOLR1 is started. >> * I’m creating a core (Core1) using SOLR1. >> * After filling it to some capacity, I unload this core without deleting >> the data. >> * I would now start SOLR2 and would like to point SOLR2 to Core1. >> Can someone please share me the details on how I can achieve this? > > In Solr 4.4, the core discovery process became usable. In 4.x versions > starting with 4.4, core discovery was optional, but recommended. > > https://wiki.apache.org/solr/Core%20Discovery%20%284.4%20and%20beyond%29 > > In Solr 5.0, the old solr.xml way of specifying cores was removed, and > now Solr only supports core discovery. > > Through the CoreAdmin API, you can add Solr cores that are positioned > anywhere on the filesystem, but if you want them to be found on startup, > they must all be located in one place, typically underneath the solr > home directory. You can use filesystem tricks like symlinks to have the > true locations be variable. > > It would be a very bad idea to try and have two Solr instances pointing > at the same solr home, unless you could be absolutely certain that they > would never run at the same time. Instead, you should move or copy a > core from one instance's solr home to that of another instance to > transfer it. > > Thanks, > Shawn >
