[SOLR-5683] Documentation of Suggester V2

• Type: Task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.10, 6.0
• Component/s: SearchComponents - other
• Assignee: Cassandra Targett
• Reporter: Areek Zillur
• Created: 31/Jan/14 03:42
• Updated: 21/Nov/19 00:42
• Resolved: 21/Aug/14 20:26

Description

Place holder for documentation that will eventually end up in the Solr Ref guide.
====
The new Suggester Component allows Solr to fully utilize the Lucene suggesters.
The main features are:

• lookup pluggability (TODO: add description):
  • AnalyzingInfixLookupFactory
  • AnalyzingLookupFactory
  • FuzzyLookupFactory
  • FreeTextLookupFactory
  • FSTLookupFactory
  • WFSTLookupFactory
  • TSTLookupFactory
  • JaspellLookupFactory
• Dictionary pluggability (give users the option to choose the dictionary implementation to use for their suggesters to consume)
  • Input from search index
    • DocumentDictionaryFactory – user can specify suggestion field along with optional weight and payload fields from their search index.
    • DocumentExpressionFactory – same as DocumentDictionaryFactory but allows users to specify arbitrary expression using existing numeric fields.
    • HighFrequencyDictionaryFactory – user can specify a suggestion field and specify a threshold to prune out less frequent terms.
  • Input from external files
    • FileDictionaryFactory – user can specify a file which contains suggest entries, along with optional weights and payloads.

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 (can occur multiple times for batching suggester requests)
• 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
• buildAll – command to build all suggesters in the component
• reloadAll – command to reload all suggesters in the component

Example query:

http://localhost:8983/solr/suggest?suggest.dictionary=suggester1&suggest=true&suggest.build=true&suggest.q=elec

Distributed query:

http://localhost:7574/solr/suggest?suggest.dictionary=suggester2&suggest=true&suggest.build=true&suggest.q=elec&shards=localhost:8983/solr,localhost:7574/solr&shards.qt=/suggest

Response Format:
The response format can be either XML or JSON. The typical response structure is as follows:

{
  suggest: {
    suggester_name: {
       suggest_query: { numFound:  .., suggestions: [ {term: .., weight: .., payload: ..}, .. ]} 
   }
}	

Example Response:

{
    responseHeader: {
        status: 0,
        QTime: 3
    },
    suggest: {
        suggester1: {
            e: {
                numFound: 1,
                suggestions: [
                    {
                        term: "electronics and computer1",
                        weight: 100,
                        payload: ""
                    }
                ]
            }
        },
        suggester2: {
            e: {
                numFound: 1,
                suggestions: [
                    {
                        term: "electronics and computer1",
                        weight: 10,
                        payload: ""
                    }
                ]
            }
        }
    }
}

Example solrconfig snippet with multiple suggester configuration:

  
  <searchComponent name="suggest" class="solr.SuggestComponent">
    <lst name="suggester">
      <str name="name">suggester1</str>
      <str name="lookupImpl">FuzzyLookupFactory</str>      
      <str name="dictionaryImpl">DocumentDictionaryFactory</str>      
      <str name="field">cat</str>
      <str name="weightField">price</str>
      <str name="suggestAnalyzerFieldType">string</str>
    </lst>
   <lst name="suggester">
        <str name="name">suggester2 </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-5378 Suggester Version 2