[SOLR-11386] Extracting learning to rank features fails when word ordering of EFI argument changed.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Workaround
• Affects Version/s: 6.5.1
• Component/s: contrib - LTR
• Assignee: Unassigned
• Reporter: Michael A. Alcorn
• Created: 21/Sep/17 17:13
• Updated: 08/Jun/19 15:24
• Resolved: 01/Nov/17 18:28

Description

I'm getting some extremely strange behavior when trying to extract features for a learning to rank model. The following query incorrectly says all features have zero values:

http://gss-test-fusion.usersys.redhat.com:8983/solr/access/query?q=added couple of fiber channel&rq={!ltr model=redhat_efi_model reRankDocs=1 efi.case_summary=the efi.case_description=added couple of fiber channel efi.case_issue=the efi.case_environment=the}&fl=id,score,[features]&rows=10

But this query, which simply moves the word "added" from the front of the provided text to the back, properly fills in the feature values:

http://gss-test-fusion.usersys.redhat.com:8983/solr/access/query?q=couple of fiber channel added&rq={!ltr model=redhat_efi_model reRankDocs=1 efi.case_summary=the efi.case_description=couple of fiber channel added efi.case_issue=the efi.case_environment=the}&fl=id,score,[features]&rows=10

The explain output for the failing query can be found here:

https://gist.github.com/manisnesan/18a8f1804f29b1b62ebfae1211f38cc4

and the explain output for the properly functioning query can be found here:

https://gist.github.com/manisnesan/47685a561605e2229434b38aed11cc65