[SOLR-5378] Suggester Version 2

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.7, 6.0
• Component/s: search
• Assignee: Shalin Shekhar Mangar
• Reporter: Areek Zillur
• Created: 23/Oct/13 08:12
• Updated: 09/May/16 18:51
• Resolved: 25/Nov/13 15:30

Description

The idea is to add a new Suggester Component that will eventually replace the Suggester support through the SpellCheck Component.
This will enable Solr to fully utilize the Lucene suggester module (along with supporting most of the existing features) in the following ways:

• Dictionary pluggability (give users the option to choose the dictionary implementation to use for their suggesters to consume)
• Map the suggester options/ suggester result format (e.g. support for payload)
• The new Component will also allow us to have "beefier" Lookup support instead of resorting to collation and such. (Move computation from query time to index time) with more freedom

In addition to this, this suggester version should also have support for distributed support, which was awkward at best with the previous implementation due to SpellCheck requirements.

Config (index time) options:

• name - name of suggester
• sourceLocation - external file location (for file-based suggesters)
• lookupImpl - type of lookup to use [default JaspellLookupFactory]
• dictionaryImpl - type of dictionary to use (lookup input) [default
  (sourceLocation == null ? HighFrequencyDictionaryFactory : FileDictionaryFactory)]
• storeDir - location to store in-memory data structure in disk
• buildOnCommit - command to build suggester for every commit
• buildOnOptimize - command to build suggester for every optimize

Query time options:

• suggest.dictionary - name of suggester to use
• suggest.count - number of suggestions to return
• suggest.q - query to use for lookup
• suggest.build - command to build the suggester
• suggest.reload - command to reload the suggester

Example query:

http://localhost:8983/solr/suggest?suggest.dictionary=mySuggester&suggest=true&suggest.build=true&suggest.q=elec

Distributed query:

http://localhost:7574/solr/suggest?suggest.dictionary=mySuggester&suggest=true&suggest.build=true&suggest.q=elec&shards=localhost:8983/solr,localhost:7574/solr&shards.qt=/suggest

Example Response:

<response>
  <lst name="responseHeader">
    <int name="status">0</int>
    <int name="QTime">28</int>
  </lst>
  <str name="command">build</str>
  <result name="response" numFound="0" start="0" maxScore="0.0"/>
  <lst name="suggest">
    <lst name="suggestions">
      <lst name="e">
        <int name="numFound">2</int>
        <lst name="suggestion">
          <str name="term">electronics and computer1</str>
          <long name="weight">2199</long>
          <str name="payload"/>
        </lst>
        <lst name="suggestion">
          <str name="term">electronics</str>
          <long name="weight">649</long>
          <str name="payload"/>
        </lst>
      </lst>
    </lst>
  </lst>
</response>

Example config file:

• Using DocumentDictionary and FuzzySuggester
  • Suggestion on product_name sorted by popularity with the additional product_id in the payload

  
  <searchComponent class="solr.SuggestComponent" name="suggest">
      <lst name="suggester">
        <str name="name">suggest_fuzzy_doc_dict</str>
        <str name="lookupImpl">FuzzyLookupFactory</str>
        <str name="dictionaryImpl">DocumentDictionaryFactory</str>
        <str name="field">product_name</str>
        <str name="weightField">popularity</str>
        <str name="payloadField">product_id</str>
        <str name="storeDir">suggest_fuzzy_doc_dict_payload</str>
        <str name="suggestAnalyzerFieldType">text</str>
      </lst>
    </searchComponent>

• Using DocumentExpressionDictionary and FuzzySuggester
  • Suggestion on product_name sorted by the expression "((price * 2) + ln(popularity))" (where both price and popularity are fields in the document)

    <searchComponent class="solr.SuggestComponent" name="suggest">
      <lst name="suggester">
        <str name="name">suggest_fuzzy_doc_expr_dict</str>
        <str name="dictionaryImpl">DocumentExpressionDictionaryFactory</str>
        <str name="lookupImpl">FuzzyLookupFactory</str>
        <str name="field">product_name</str>
        <str name="weightExpression">((price * 2) + ln(popularity))</str>
        <str name="sortField">weight</str>
        <str name="sortField">price</str>
        <str name="strtoreDir">suggest_fuzzy_doc_expr_dict</str>
        <str name="suggestAnalyzerFieldType">text</str>
      </lst>
    </searchComponent>

Issue Links

• is related to: SOLR-5631 Add support for FreeTextSuggester in SolrSuggester Component
• is related to: SOLR-5528 Change New Suggester Response and minor cleanups
• is related to: SOLR-5529 Add Support for queries to use multiple suggesters (new Suggester Component)
• relates to: SOLR-5683 Documentation of Suggester V2