Hi, I am trying to work with multi-threaded faceting on SolrCloud and in the process i was hit by some issues.
I am currently running the below upstream test on different SolrCloud configurations and i am getting a different result set per configuration. https://github.com/apache/lucene-solr/blob/trunk/solr/core/src/test/org/apache/solr/request/TestFaceting.java#L654 Setup: ** Indexed 50 docs into SolrCloud.* ** If the SolrCloud has only 1 shard, the facet field query has the below output (which matches with the expected upstream test output - # facet fields ~ 50 <https://github.com/apache/lucene-solr/blob/trunk/solr/core/src/test/org/apache/solr/request/TestFaceting.java#L716>).* > $ curl " > http://localhost:8983/solr/collection1/select?facet=true&fl=id&indent=true&q=id%3A*&facet.limit=-1&facet.threads=1000&facet.field=f0_ws&facet.field=f0_ws&facet.field=f0_ws&facet.field=f0_ws&facet.field=f0_ws&facet.field=f1_ws&facet.field=f1_ws&facet.field=f1_ws&facet.field=f1_ws&facet.field=f1_ws&facet.field=f2_ws&facet.field=f2_ws&facet.field=f2_ws&facet.field=f2_ws&facet.field=f2_ws&facet.field=f3_ws&facet.field=f3_ws&facet.field=f3_ws&facet.field=f3_ws&facet.field=f3_ws&facet.field=f4_ws&facet.field=f4_ws&facet.field=f4_ws&facet.field=f4_ws&facet.field=f4_ws&facet.field=f5_ws&facet.field=f5_ws&facet.field=f5_ws&facet.field=f5_ws&facet.field=f5_ws&facet.field=f6_ws&facet.field=f6_ws&facet.field=f6_ws&facet.field=f6_ws&facet.field=f6_ws&facet.field=f7_ws&facet.field=f7_ws&facet.field=f7_ws&facet.field=f7_ws&facet.field=f7_ws&facet.field=f8_ws&facet.field=f8_ws&facet.field=f8_ws&facet.field=f8_ws&facet.field=f8_ws&facet.field=f9_ws&facet.field=f9_ws&facet.field=f9_ws&facet.field=f9_ws&facet.field=f9_ws&rows=1&wt=xml > " > > <?xml version="1.0" encoding="UTF-8"?> > <response> > <lst name="responseHeader"> > <int name="status">0</int> > <int name="QTime">21</int> > <lst name="params"> > <str name="facet">true</str> > <str name="fl">id</str> > <str name="indent">true</str> > <str name="q">id:*</str> > <str name="facet.limit">-1</str> > <str name="facet.threads">1000</str> > <arr name="facet.field"> <str>f0_ws</str> > <str>f0_ws</str> > <str>f0_ws</str> > <str>f0_ws</str> > <str>f0_ws</str> > <str>f1_ws</str> > <str>f1_ws</str> > <str>f1_ws</str> > <str>f1_ws</str> > <str>f1_ws</str> > <str>f2_ws</str> > <str>f2_ws</str> > <str>f2_ws</str> > <str>f2_ws</str> > <str>f2_ws</str> > <str>f3_ws</str> > <str>f3_ws</str> > <str>f3_ws</str> > <str>f3_ws</str> > <str>f3_ws</str> > <str>f4_ws</str> > <str>f4_ws</str> > <str>f4_ws</str> > <str>f4_ws</str> > <str>f4_ws</str> > <str>f5_ws</str> > <str>f5_ws</str> > <str>f5_ws</str> > <str>f5_ws</str> > <str>f5_ws</str> > <str>f6_ws</str> > <str>f6_ws</str> > <str>f6_ws</str> > <str>f6_ws</str> > <str>f6_ws</str> > <str>f7_ws</str> > <str>f7_ws</str> <str>f7_ws</str> > <str>f7_ws</str> > <str>f7_ws</str> > <str>f8_ws</str> > <str>f8_ws</str> > <str>f8_ws</str> > <str>f8_ws</str> > <str>f8_ws</str> > <str>f9_ws</str> > <str>f9_ws</str> > <str>f9_ws</str> > <str>f9_ws</str> > <str>f9_ws</str> > </arr> > <str name="wt">xml</str> > <str name="rows">1</str> > </lst> > </lst> > <result name="response" numFound="50" start="0"> > <doc> > <float name="id">0.0</float></doc> > </result> > <lst name="facet_counts"> > <lst name="facet_queries"/> > <lst name="facet_fields"> > <lst name="f0_ws"> > <int name="zero_1">25</int> > <int name="zero_2">25</int> > </lst> > <lst name="f0_ws"> > <int name="zero_1">25</int> > <int name="zero_2">25</int> > </lst> > <lst name="f0_ws"> > <int name="zero_1">25</int> > <int name="zero_2">25</int> > </lst> > <lst name="f0_ws"> > <int name="zero_1">25</int> > <int name="zero_2">25</int> > </lst> > <lst name="f0_ws"> > <int name="zero_1">25</int> > <int name="zero_2">25</int> > </lst> > <lst name="f1_ws"> > <int name="one_1">33</int> > <int name="one_3">17</int> > </lst> > <lst name="f1_ws"> > <int name="one_1">33</int> > <int name="one_3">17</int> > </lst> > <lst name="f1_ws"> > <int name="one_1">33</int> > <int name="one_3">17</int> > </lst> > <lst name="f1_ws"> > <int name="one_1">33</int> > <int name="one_3">17</int> > </lst> > <lst name="f1_ws"> > <int name="one_1">33</int> > <int name="one_3">17</int> > </lst> > <lst name="f2_ws"> > <int name="two_1">37</int> > <int name="two_4">13</int> > </lst> > <lst name="f2_ws"> > <int name="two_1">37</int> > <int name="two_4">13</int> > </lst> > <lst name="f2_ws"> > <int name="two_1">37</int> > <int name="two_4">13</int> > </lst> > <lst name="f2_ws"> > <int name="two_1">37</int> > <int name="two_4">13</int> > </lst> > <lst name="f2_ws"> > <int name="two_1">37</int> > <int name="two_4">13</int> > </lst> > <lst name="f3_ws"> > <int name="three_1">40</int> > <int name="three_5">10</int> > </lst> > <lst name="f3_ws"> > <int name="three_1">40</int> > <int name="three_5">10</int> > </lst> > <lst name="f3_ws"> > <int name="three_1">40</int> > <int name="three_5">10</int> > </lst> > <lst name="f3_ws"> > <int name="three_1">40</int> > <int name="three_5">10</int> > </lst> > <lst name="f3_ws"> > <int name="three_1">40</int> > <int name="three_5">10</int> > </lst> > <lst name="f4_ws"> > <int name="four_1">41</int> > <int name="four_6">9</int> > </lst> > <lst name="f4_ws"> > <int name="four_1">41</int> > <int name="four_6">9</int> > </lst> > <lst name="f4_ws"> > <int name="four_1">41</int> > <int name="four_6">9</int> > </lst> > <lst name="f4_ws"> > <int name="four_1">41</int> > <int name="four_6">9</int> > </lst> > <lst name="f4_ws"> > <int name="four_1">41</int> > <int name="four_6">9</int> > </lst> > <lst name="f5_ws"> > <int name="five_1">42</int> > <int name="five_7">8</int> > </lst> > <lst name="f5_ws"> > <int name="five_1">42</int> > <int name="five_7">8</int> > </lst> > <lst name="f5_ws"> > <int name="five_1">42</int> > <int name="five_7">8</int> > </lst> > <lst name="f5_ws"> > <int name="five_1">42</int> > <int name="five_7">8</int> > </lst> > <lst name="f5_ws"> > <int name="five_1">42</int> > <int name="five_7">8</int> > </lst> > <lst name="f6_ws"> > <int name="six_1">43</int> > <int name="six_8">7</int> > </lst> > <lst name="f6_ws"> > <int name="six_1">43</int> > <int name="six_8">7</int> > </lst> > <lst name="f6_ws"> > <int name="six_1">43</int> > <int name="six_8">7</int> > </lst> > <lst name="f6_ws"> > <int name="six_1">43</int> > <int name="six_8">7</int> > </lst> > <lst name="f6_ws"> > <int name="six_1">43</int> > <int name="six_8">7</int> > </lst> > <lst name="f7_ws"> > <int name="seven_1">44</int> > <int name="seven_9">6</int> > </lst> > <lst name="f7_ws"> > <int name="seven_1">44</int> > <int name="seven_9">6</int> > </lst> > <lst name="f7_ws"> > <int name="seven_1">44</int> > <int name="seven_9">6</int> > </lst> > <lst name="f7_ws"> > <int name="seven_1">44</int> > <int name="seven_9">6</int> > </lst> > <lst name="f7_ws"> > <int name="seven_1">44</int> > <int name="seven_9">6</int> > </lst> > <lst name="f8_ws"> > <int name="eight_1">45</int> > <int name="eight_10">5</int> > </lst> > <lst name="f8_ws"> > <int name="eight_1">45</int> > <int name="eight_10">5</int> > </lst> > <lst name="f8_ws"> > <int name="eight_1">45</int> > <int name="eight_10">5</int> > </lst> > <lst name="f8_ws"> > <int name="eight_1">45</int> > <int name="eight_10">5</int> > </lst> > <lst name="f8_ws"> > <int name="eight_1">45</int> > <int name="eight_10">5</int> > </lst> > <lst name="f9_ws"> > <int name="nine_1">45</int> > <int name="nine_11">5</int> > </lst> > <lst name="f9_ws"> > <int name="nine_1">45</int> > <int name="nine_11">5</int> > </lst> > <lst name="f9_ws"> > <int name="nine_1">45</int> > <int name="nine_11">5</int> > </lst> > <lst name="f9_ws"> > <int name="nine_1">45</int> > <int name="nine_11">5</int> > </lst> > <lst name="f9_ws"> > <int name="nine_1">45</int> > <int name="nine_11">5</int> > </lst> > </lst> > <lst name="facet_dates"/> > <lst name="facet_ranges"/> > </lst> > </response> ** Now, if a create a new collection with 2 shards (>1 shard SolrCloud), the same above query results in a different output. (# facet fields ~ 10 ; Expected 50)* > $ curl " > http://localhost:8983/solr/collection1/select?facet=true&fl=id&indent=true&q=id%3A*&facet.limit=-1&facet.threads=1000&facet.field=f0_ws&facet.field=f0_ws&facet.field=f0_ws&facet.field=f0_ws&facet.field=f0_ws&facet.field=f1_ws&facet.field=f1_ws&facet.field=f1_ws&facet.field=f1_ws&facet.field=f1_ws&facet.field=f2_ws&facet.field=f2_ws&facet.field=f2_ws&facet.field=f2_ws&facet.field=f2_ws&facet.field=f3_ws&facet.field=f3_ws&facet.field=f3_ws&facet.field=f3_ws&facet.field=f3_ws&facet.field=f4_ws&facet.field=f4_ws&facet.field=f4_ws&facet.field=f4_ws&facet.field=f4_ws&facet.field=f5_ws&facet.field=f5_ws&facet.field=f5_ws&facet.field=f5_ws&facet.field=f5_ws&facet.field=f6_ws&facet.field=f6_ws&facet.field=f6_ws&facet.field=f6_ws&facet.field=f6_ws&facet.field=f7_ws&facet.field=f7_ws&facet.field=f7_ws&facet.field=f7_ws&facet.field=f7_ws&facet.field=f8_ws&facet.field=f8_ws&facet.field=f8_ws&facet.field=f8_ws&facet.field=f8_ws&facet.field=f9_ws&facet.field=f9_ws&facet.field=f9_ws&facet.field=f9_ws&facet.field=f9_ws&rows=1&wt=xml > " > <?xml version="1.0" encoding="UTF-8"?> > <response> > <lst name="responseHeader"> > <int name="status">0</int> > <int name="QTime">31</int> > <lst name="params"> > <str name="facet">true</str> > <str name="fl">id</str> > <str name="indent">true</str> > <str name="q">id:*</str> > <str name="facet.limit">-1</str> > <str name="facet.threads">1000</str> > <arr name="facet.field"> > <str>f0_ws</str> > <str>f0_ws</str> > <str>f0_ws</str> > <str>f0_ws</str> > <str>f0_ws</str> > <str>f1_ws</str> > <str>f1_ws</str> > <str>f1_ws</str> > <str>f1_ws</str> > <str>f1_ws</str> > <str>f2_ws</str> > <str>f2_ws</str> > <str>f2_ws</str> > <str>f2_ws</str> > <str>f2_ws</str> > <str>f3_ws</str> > <str>f3_ws</str> > <str>f3_ws</str> > <str>f3_ws</str> > <str>f3_ws</str> > <str>f4_ws</str> > <str>f4_ws</str> > <str>f4_ws</str> > <str>f4_ws</str> > <str>f4_ws</str> > <str>f5_ws</str> > <str>f5_ws</str> > <str>f5_ws</str> > <str>f5_ws</str> > <str>f5_ws</str> > <str>f6_ws</str> > <str>f6_ws</str> > <str>f6_ws</str> > <str>f6_ws</str> > <str>f6_ws</str> > <str>f7_ws</str> > <str>f7_ws</str> > <str>f7_ws</str> > <str>f7_ws</str> > <str>f7_ws</str> > <str>f8_ws</str> > <str>f8_ws</str> > <str>f8_ws</str> > <str>f8_ws</str> > <str>f8_ws</str> > <str>f9_ws</str> > <str>f9_ws</str> > <str>f9_ws</str> > <str>f9_ws</str> > <str>f9_ws</str> > </arr> > <str name="wt">xml</str> > <str name="rows">1</str> > </lst> > </lst> > <result name="response" numFound="50" start="0" maxScore="1.0"> > <doc> > <float name="id">2.0</float></doc> > </result> > <lst name="facet_counts"> > <lst name="facet_queries"/> > <lst name="facet_fields"> > <lst name="f0_ws"> > <int name="zero_1">25</int> > <int name="zero_2">25</int> > </lst> > <lst name="f1_ws"> > <int name="one_1">33</int> > <int name="one_3">17</int> > </lst> > <lst name="f2_ws"> > <int name="two_1">37</int> > <int name="two_4">13</int> > </lst> > <lst name="f3_ws"> > <int name="three_1">40</int> > <int name="three_5">10</int> > </lst> > <lst name="f4_ws"> > <int name="four_1">41</int> > <int name="four_6">9</int> > </lst> > <lst name="f5_ws"> > <int name="five_1">42</int> > <int name="five_7">8</int> > </lst> > <lst name="f6_ws"> > <int name="six_1">43</int> > <int name="six_8">7</int> > </lst> > <lst name="f7_ws"> > <int name="seven_1">44</int> > <int name="seven_9">6</int> > </lst> > <lst name="f8_ws"> > <int name="eight_1">45</int> > <int name="eight_10">5</int> > </lst> > <lst name="f9_ws"> > <int name="nine_1">45</int> > <int name="nine_11">5</int> > </lst> > </lst> > <lst name="facet_dates"/> > <lst name="facet_ranges"/> > </lst> > </response> I actually feel this behavior is quite strange as it is being dependent on the number of shards in SolrCloud. I would really appreciate if someone can explain this behavior. If it is indeed a bug, i will file a Solr Jira. Thanks, Vamsee