When is Luke data distributed across Solr cores?

Question

On a Solr installation with 2+ shards, when is the data returned by the LukeRequestHandler distributed across the shards? I ask because I want to be able to detect new (previously unseen) dynamic fields within a short amount of time after they are added.

Example desired sequence of events:

1. Assume dynamic field *_s
2. Query Luke and receive list of dynamic fields
3. Add document with field example_s
4. Query Luke and receive same list as before but with additional example_s in result (this currently doesn't happen)
5. Query collection for example_s:* and match the document added above

I am aware that newly added documents become immediately searchable even before being hard committed, but I am looking for a way to have that info appear in Luke too.

Info on the following would be useful:

• Does Luke query all shards at request time, or just one? It would appear to only query one at random.

• Exactly when does knowledge of previously unseen dynamic fields become distributed across all shards (equivalently, available to Luke)?

• Can I configure the delay/trigger for this supposed Luke propagation in order to minimize the delay between addition of a document with a new dynamic field on an arbitrary shard and the moment it becomes visible in Luke responses on every other shard?

See https://issues.apache.org/jira/browse/SOLR-8127

Answer 1

You need to query each shard directly. This can be done by using the exact core path /solr/collection_shard1_replica1/admin/luke

Answer 2

Never.

As indicated by responses on the linked ticket, the Luke request handler isn't at a high enough level to understand multiple shards. Luke provides information about an index, not a collection, and certainly not a cluster.