AnalyzingInfixLookupFactory implementation in Solr Suggestor not returning suggestion results

Question

My requirement is to provide automatic suggestions to users on asset names as per their project. I have tried using AnalyzingInfixLookupFactory and BlendedInfixLookupFactory, as these are the only ones that support context filtering. But no suggestion results are being returned. Below is extract from solrconfig.xml:

<searchComponent name="suggest" class="solr.SuggestComponent">

<lst name="suggester">

<str name="name">mySuggester</str>

<str name="lookupImpl">AnalyzingInfixLookupFactory</str>

<str name="dictionaryImpl">DocumentDictionaryFactory</str>

<str name="field">assetname_str</str>

<str name="indexPath">/home/suggest_index</str>

<str name="contextField">projectid</str>

<str name="weightField">weight</str>

<str name="suggestAnalyzerFieldType">string</str>

<str name="buildOnStartup">false</str>

<str name="buildOnCommit">false</str>

</lst>

</searchComponent>

<requestHandler name="/suggest" class="solr.SearchHandler" startup="lazy">

<lst name="defaults">

<str name="suggest">true</str>

<str name="suggest.count">10</str>

<str name="suggest.dictionary">mySuggester</str>

</lst>

<arr name="components">

<str>suggest</str>

</arr>

</requestHandler>

However if I try using FuzzyLookupFactory as lookup Impl, then suggestion results are returned as expected.(but problem is Fuzzylookupfactory does not support context filtering)

url used: http://ipaddress:port/solr/collection_name/suggest?suggest=true&suggest.build=true&suggest.dictionary=mySuggester&wt=json&suggest.q=Com&suggest.cfq= 1234

Answer 1

(I know this is an old issue, but in case others stumble across it with the same problem...)

I spent a couple of days dealing with the same empty results. You don't say what the type of the field is that you're using as material for suggestions. You've got suggestAnalyzerFieldType set to string.

By default, string is a fieldType with no analysis many out-of-the-box schema.xml examples. A key concept, which is only vaguely hinted at in the Solr manual's Suggester doc, is that lookupImpls like AnalyzingInfixLookupFactory and BlendedInfixLookupFactory can take a suggestAnalyzerFieldType that is not the type of the field from which you are generating suggestions, but rather need a type that contains the appropriate analyzer elements, such as solr.WhiteSpaceTokenizer needed for suggestions.

In my case, I was trying to suggest from a multivalued string field--I wanted the field to have no tokenization. But until I changed the suggestAnalyzerFieldType from string to text_ws (a fieldType whose analyzer is only sole.WhiteSpaceTokenizer, I got empty results.

For what it's worth, if you use multivalued string field for suggestions, and many documents that contain the same string values in that field, then the BlendedInfixLookupFactory seems to produce a better result with no duplicate suggestions.