Thanks, Shawn. This is very helpful. I will use this solution! On Sun, Nov 20, 2022 at 12:56 PM Shawn Heisey <apa...@elyograg.org> wrote:
> On 11/19/22 21:38, gnandre wrote: > > Thanks, Shawn. I am a bit wary of creating a total core just for this > > health check purpose. > > Isn't it a bit expensive to create a core, considering the caches and so > > many things it registers? Or, is it fine in which case I might just > proceed > > with that solution. > > I'm talking about a completely empty core that you never send queries > to. If it never gets queries, it should not need any significant memory > for caching. > > This is the absolute minimum config and schema I was able to use to make > a new core like what you would need. There are no cache definitions, so > the Solr caches should not even be created. It would probably still > create some Lucene caches, but as those would be empty, they would be > very small. With this definition I don't think you CAN send it any > queries: > > solrconfig.xml: > --- > <?xml version="1.0" encoding="UTF-8" ?> > <config> > <luceneMatchVersion>LATEST</luceneMatchVersion> > <requestHandler name="/your/handler/path" class="YOURCLASSNAME"> > *** ANY CONFIG NEEDED FOR YOUR HANDLER *** > </requestHandler> > </config> > --- > > managed-schema.xml: > --- > <?xml version="1.0" encoding="UTF-8"?> > <schema name="empty" version="1.6"> > <fieldType name="string" class="solr.StrField" omitNorms="true" > sortMissingLast="true" docValues="true"/> > <fieldType name="long" class="solr.LongPointField" > positionIncrementGap="0" docValues="true"/> > <field name="id" type="string" indexed="true" required="true" > stored="true"/> > <field name="_version_" type="long" indexed="false" stored="false"/> > <uniqueKey>id</uniqueKey> > </schema> > --- > > This should result in the absolute minimum memory footprint for a core. > Probably only a few megabytes. And I think there is some work underway > to try and reduce the memory footprint for all cores in some future > version of Solr. That would in theory make the memory requirement for > this core even smaller. > > In the future I hope that we can provide a way for users to register > global handlers and make this empty core nonsense unnecessary. > > Thanks, > Shawn > >
