[SOLR-6345] collapsingQParserPlugin degraded performance when using tagging

• Type: Bug
• Status: Open
• Priority: Critical
• Resolution: Unresolved
• Affects Version/s: 4.7.2
• Component/s: query parsers
• Labels: collapsingQParserPlugin
• Assignee: Unassigned
• Reporter: David Boychuck
• Created: 08/Aug/14 18:41
• Updated: 11/Jan/18 21:15

Description

I am having a problem with degraded performance when using the collapseQParserPlugin with facet tagging.

An example query would look something like this

http://host:port/solr/index/handler?facet=true&fq={!collapse field=groupid}&facet.query={!ex=Width_numeric}Width_numeric:[10+TO+15]&facet.query={!ex=Width_numeric}Width_numeric:[15+TO+20]&facet.sort=index&start=0&q=36+x+42+shower+base&fq={!tag%3DWidth_numeric}Width_numeric:[35+TO+40]

When I either remove the grouping

fq={!collapse field=groupid}

or remove the tag

&fq={!tag%3DWidth_numeric}Width_numeric:[35+TO+40]

I am getting requests orders of magnitude faster. In my production environment with around 800k documents. I jump from less than 20ms to over 100ms sometimes 200ms using the collapsingQParserPlugin with tagging.

The issue can be observed in the TestCollapseQParserPlugin tests:

params.add("q", "*:*");
    params.add("fq", "{!collapse field=group_s}");
    params.add("defType", "edismax");
    params.add("bf", "field(test_ti)");
    params.add("facet", "true");
    params.add("facet.field", "{!ex=test_ti}test_ti");
    params.add("fq", "{!tag=test_ti}test_ti:10");
    assertQ(req(params), "*[count(//doc)=3]",
                       "//result/doc[1]/float[@name='id'][.='2.0']",
                       "//result/doc[2]/float[@name='id'][.='6.0']"
        );

With this test with the tagging I ran 10 tests and consistently got response times between 23-28ms. When I removed the tag and ran 10 more tests I consistently got results between 15-18ms

In all cases if I don't use the collapseQParserPlugin with tagging by either removing the tag or leaving the tag but removing the collapse I am getting poor performance.