[SOLR-6299] Facet count on facet queries returns different results if #shards > 1

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Not A Problem
• Affects Version/s: 6.0
• Component/s: SolrCloud
• Labels: faceting
• Assignee: Unassigned
• Reporter: Vamsee K. Yarlagadda
• Created: 29/Jul/14 20:52
• Updated: 02/Oct/19 17:30
• Resolved: 02/Aug/14 01:13

Description

I am trying to run some facet counts on facet queries and looks like i am getting different counts if i use >1 shards in the SolrCloud cluster.

Here is the upstream unit test:
https://github.com/apache/lucene-solr/blob/trunk/solr/core/src/test/org/apache/solr/request/SimpleFacetsTest.java#L173

Setup:

• Ingested 5 solr docs.

  {
    "responseHeader": {
      "status": 0,
      "QTime": 22,
      "params": {
        "indent": "true",
        "q": "*:*",
        "_": "1406346687337",
        "wt": "json"
      }
    },
    "response": {
      "numFound": 5,
      "start": 0,
      "maxScore": 1,
      "docs": [
        {
          "id": 2004,
          "range_facet_l": [
            2004
          ],
          "hotel_s1": "b",
          "airport_s1": "ams",
          "duration_i1": 5,
          "_version_": 1474661321774465000,
          "timestamp": "2014-07-26T03:50:27.975Z",
          "multiDefault": [
            "muLti-Default"
          ],
          "intDefault": 42
        },
        {
          "id": 2000,
          "range_facet_l": [
            2000
          ],
          "hotel_s1": "a",
          "airport_s1": "ams",
          "duration_i1": 5,
          "_version_": 1474661323604230100,
          "timestamp": "2014-07-26T03:50:29.734Z",
          "multiDefault": [
            "muLti-Default"
          ],
          "intDefault": 42
        },
        {
          "id": 2003,
          "range_facet_l": [
            2003
          ],
          "hotel_s1": "b",
          "airport_s1": "ams",
          "duration_i1": 5,
          "_version_": 1474661326312702000,
          "timestamp": "2014-07-26T03:50:32.317Z",
          "multiDefault": [
            "muLti-Default"
          ],
          "intDefault": 42
        },
        {
          "id": 2001,
          "range_facet_l": [
            2001
          ],
          "hotel_s1": "a",
          "airport_s1": "dus",
          "duration_i1": 10,
          "_version_": 1474661326389248000,
          "timestamp": "2014-07-26T03:50:32.375Z",
          "multiDefault": [
            "muLti-Default"
          ],
          "intDefault": 42
        },
        {
          "id": 2002,
          "range_facet_l": [
            2002
          ],
          "hotel_s1": "b",
          "airport_s1": "ams",
          "duration_i1": 10,
          "_version_": 1474661326464745500,
          "timestamp": "2014-07-26T03:50:32.446Z",
          "multiDefault": [
            "muLti-Default"
          ],
          "intDefault": 42
        }
      ]
    }
  }
  

Here is the query being run:

Test code:
    assertQ(
        req(
            "q", "*:*",
            "fq", "id:[2000 TO 2004]",
            "group", "true",
            "group.facet", "true",
            "group.field", "hotel_s1",
            "facet", "true",
            "facet.limit", facetLimit,
            "facet.query", "airport_s1:ams"
        ),
        "//lst[@name='facet_queries']/int[@name='airport_s1:ams'][.='2']"
    );

$ curl  "http://localhost:8983/solr/collection1/select?facet=true&facet.query=airport_s1%3Aams&q=*%3A*&facet.limit=-100&group.field=hotel_s1&group=true&group.facet=true&fq=id%3A%5B2000+TO+2004%5D&indent=true&wt=xml" 

Now, if i issue a query statement - On 1 shard system (Works as expected)

$ curl  "http://localhost:8983/solr/collection1/select?facet=true&facet.query=airport_s1%3Aams&q=*%3A*&facet.limit=-100&group.field=hotel_s1&group=true&group.facet=true&fq=id%3A%5B2000+TO+2004%5D&indent=true&wt=xml" 

<?xml version="1.0" encoding="UTF-8"?>
<response>

<lst name="responseHeader">
  <int name="status">0</int>
  <int name="QTime">17</int>
  <lst name="params">
    <str name="facet">true</str>
    <str name="indent">true</str>
    <str name="facet.query">airport_s1:ams</str>
    <str name="q">*:*</str>
    <str name="facet.limit">-100</str>
    <str name="group.field">hotel_s1</str>
    <str name="group">true</str>
    <str name="wt">xml</str>
    <str name="fq">id:[2000 TO 2004]</str>
    <str name="group.facet">true</str>
  </lst>
</lst>
<lst name="grouped">
  <lst name="hotel_s1">
    <int name="matches">5</int>
    <arr name="groups">
      <lst>
        <str name="groupValue">a</str>
        <result name="doclist" numFound="2" start="0">
          <doc>
            <int name="id">2001</int>
            <arr name="range_facet_l">
              <long>2001</long>
            </arr>
            <str name="hotel_s1">a</str>
            <str name="airport_s1">dus</str>
            <int name="duration_i1">10</int>
            <long name="_version_">1474989437819551744</long>
            <date name="timestamp">2014-07-29T18:45:43.819Z</date>
            <arr name="multiDefault">
              <str>muLti-Default</str>
            </arr>
            <int name="intDefault">42</int></doc>
        </result>
      </lst>
      <lst>
        <str name="groupValue">b</str>
        <result name="doclist" numFound="3" start="0">
          <doc>
            <int name="id">2003</int>
            <arr name="range_facet_l">
              <long>2003</long>
            </arr>
            <str name="hotel_s1">b</str>
            <str name="airport_s1">ams</str>
            <int name="duration_i1">5</int>
            <long name="_version_">1474989439611568128</long>
            <date name="timestamp">2014-07-29T18:45:45.528Z</date>
            <arr name="multiDefault">
              <str>muLti-Default</str>
            </arr>
            <int name="intDefault">42</int></doc>
        </result>
      </lst>
    </arr>
  </lst>
</lst>
<lst name="facet_counts">
  <lst name="facet_queries">
    <int name="airport_s1:ams">2</int>
  </lst>
  <lst name="facet_fields"/>
  <lst name="facet_dates"/>
  <lst name="facet_ranges"/>
</lst>
</response>

Now, if i run the same query on 2 shard system, i see facet count as 3 instead of 2.

Solr result on 2 shard cluster:

[systest@search-testing-c5-1 search]$ curl  "http://localhost:8983/solr/collection1/select?facet=true&facet.query=airport_s1%3Aams&q=*%3A*&facet.limit=-100&group.field=hotel_s1&group=true&group.facet=true&fq=id%3A%5B2000+TO+2004%5D&indent=true&wt=xml" 
<?xml version="1.0" encoding="UTF-8"?>
<response>

<lst name="responseHeader">
  <int name="status">0</int>
  <int name="QTime">69</int>
  <lst name="params">
    <str name="facet">true</str>
    <str name="indent">true</str>
    <str name="facet.query">airport_s1:ams</str>
    <str name="q">*:*</str>
    <str name="facet.limit">-100</str>
    <str name="group.field">hotel_s1</str>
    <str name="group">true</str>
    <str name="wt">xml</str>
    <str name="fq">id:[2000 TO 2004]</str>
    <str name="group.facet">true</str>
  </lst>
</lst>
<lst name="grouped">
  <lst name="hotel_s1">
    <int name="matches">5</int>
    <arr name="groups">
      <lst>
        <str name="groupValue">b</str>
        <result name="doclist" numFound="3" start="0" maxScore="1.0">
          <doc>
            <int name="id">2002</int>
            <arr name="range_facet_l">
              <long>2002</long>
            </arr>
            <str name="hotel_s1">b</str>
            <str name="airport_s1">ams</str>
            <int name="duration_i1">10</int>
            <long name="_version_">1474661326464745472</long>
            <date name="timestamp">2014-07-26T03:50:32.446Z</date>
            <arr name="multiDefault">
              <str>muLti-Default</str>
            </arr>
            <int name="intDefault">42</int></doc>
        </result>
      </lst>
      <lst>
        <str name="groupValue">a</str>
        <result name="doclist" numFound="2" start="0" maxScore="1.0">
          <doc>
            <int name="id">2001</int>
            <arr name="range_facet_l">
              <long>2001</long>
            </arr>
            <str name="hotel_s1">a</str>
            <str name="airport_s1">dus</str>
            <int name="duration_i1">10</int>
            <long name="_version_">1474661326389248000</long>
            <date name="timestamp">2014-07-26T03:50:32.375Z</date>
            <arr name="multiDefault">
              <str>muLti-Default</str>
            </arr>
            <int name="intDefault">42</int></doc>
        </result>
      </lst>
    </arr>
  </lst>
</lst>
<lst name="facet_counts">
  <lst name="facet_queries">
    <int name="airport_s1:ams">3</int>
  </lst>
  <lst name="facet_fields"/>
  <lst name="facet_dates"/>
  <lst name="facet_ranges"/>
</lst>
</response>

In order to replicate this, we can simply run the above test on >1 shard system and the solr response will be different.