I'm running DDF 2.26.45 on macOS and configured it to use an external Solr 8.6.1 running locally at:

http://localhost:8983/solr

DDF detects Solr correctly:

solr.client = HttpSolrClient
solr.http.url = http://localhost:8983/solr

I created a Solr core:

./solr create -c alerts -s 1 -rf 1

Solr starts correctly.

Goal

I want to ingest a simple GeoJSON file into the DDF catalog.

File: /tmp/test-location.geojson

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "geometry": {
        "type": "Point",
        "coordinates": [-77.0369, 38.9072]
      },
      "properties": {
        "name": "Test Location"
      }
    }
  ]
}

Command used inside DDF Karaf

catalog:ingest -t geojson /tmp/test-location.geojson

Also tried:

catalog:ingest -t geojson -s catalog /tmp/test-location.geojson

Result

0 file(s) ingested in 0 seconds
1 file(s) failed to be ingested. See the ingest log for more details.

Enabled debug logging:

log:set DEBUG org.codice.ddf.commands.catalog.IngestCommand

ingest_error.log excerpts

2025-12-03T13:28:26,449 | INFO  | location.geojson | ingestLogger | f.commands.catalog.IngestCommand 338 | 455 - catalog-core-commands - 2.26.45 | 0 file(s) ingested in 0 seconds [0 records/sec]
2025-12-03T13:28:26,449 | WARN  | location.geojson | ingestLogger | f.commands.catalog.IngestCommand 351 | 455 - catalog-core-commands - 2.26.45 | 1 file(s) failed to be ingested.
(repeats every attempt)

ddf.log Solr error spam

Error retrieving system alert.
org.codice.ddf.persistence.PersistenceException

Caused by: org.apache.solr.client.solrj.impl.HttpSolrClient$RemoteSolrException:
Error from server at http://localhost:8983/solr/alerts:
can not sort on multivalued field: id_txt of type: text_general

Additional details

GeoJSON transformers appear in service:list:

id = catalog.data.metacard.geojson
id = geojson
displayName = GeoJSON
shortname = geojson

The ingest command always returns:

0 ingested, 1 failed

The DDF admin UI shows:

"Persistent Storage Not Responding. Could Not Retrieve Alerts."

I only created a single Solr core named "alerts". I'm not sure what cores or configsets DDF requires when using external Solr.

Question

Exactly what Solr cores and configsets does DDF 2.26.45 require when using external Solr, and how do I configure them so that:

1. GeoJSON ingestion works
2. The Solr error "cannot sort on multivalued field: id_txt" stops
3. The internal alerts/persistence store initializes properly

If anyone has a working external-Solr setup for DDF 2.26.x, please share the required cores, configsets, and schema.xml examples.