Package com.yahoo.prelude.fastsearch

Class VespaBackEndSearcher

java.lang.Object
com.yahoo.component.AbstractComponent
com.yahoo.component.chain.ChainedComponent
com.yahoo.processing.Processor
com.yahoo.search.Searcher
com.yahoo.search.cluster.PingableSearcher
com.yahoo.prelude.fastsearch.VespaBackEndSearcher
All Implemented Interfaces:
com.yahoo.component.Component, com.yahoo.component.Deconstructable, Comparable<com.yahoo.component.Component>
Direct Known Subclasses:
FastSearcher, VdsStreamingSearcher
public abstract class VespaBackEndSearcher extends PingableSearcher
Superclass for backend searchers.
Author:
baldersheim

  • Field Details

    • SORTABLE_ATTRIBUTES_SUMMARY_CLASS

      public static final String SORTABLE_ATTRIBUTES_SUMMARY_CLASS
      for vespa-internal use only; consider renaming the summary class
      See Also:

  • Constructor Details

    • VespaBackEndSearcher

      public VespaBackEndSearcher()

  • Method Details

    • getName

      public final String getName()

    • getDefaultDocsumClass

      protected final String getDefaultDocsumClass()

    • getLogger

      public final Logger getLogger()
      Description copied from class: Searcher
      Returns a logger unique for the instance subclass
      Overrides:
      getLogger in class Searcher

    • doSearch2

      protected abstract Result doSearch2(Query query, Execution execution)
      Searches a search cluster This is an endpoint - searchers will never propagate the search to any nested searcher.
      Parameters:
      query - the query to search
      execution - the query execution context

    • doPartialFill

      protected abstract void doPartialFill(Result result, String summaryClass)

    • summaryNeedsQuery

      public boolean summaryNeedsQuery(Query query)
      Returns whether we need to send the query when fetching summaries. This is necessary if the query requests summary features or dynamic snippeting.

    • getServerId

      public String getServerId()

    • getDocumentDatabase

      public DocumentDatabase getDocumentDatabase(Query query)

    • init

      public final void init(String serverId, SummaryParameters docSumParams, ClusterParams clusterParams, DocumentdbInfoConfig documentdbInfoConfig, SchemaInfo schemaInfo)

    • transformQuery

      protected void transformQuery(Query query)

    • search

      public Result search(Query query, Execution execution)
      Description copied from class: Searcher
      Override this to implement your searcher.

      Searcher implementation subclasses will, depending on their type of logic, do one of the following:

      • Query processors: Access the query, then call execution.search and return the result
      • Result processors: Call execution.search to get the result, access it and return
      • Sources (which produces results): Create a result, add the desired hits and return it.
      • Federators (which forwards the search to multiple subchains): Call search on the desired subchains in parallel and get the results. Combine the results to one and return it.
      • Workflows: Call execution.search as many times as desired, using different queries. Eventually return a result.

      Hits come in two kinds - concrete hits are actual content of the kind requested by the user, meta hits are hits which provides information about the collection of hits, on the query, the service and so on.

      The query specifies a window into a larger result list that must be returned from the searcher through hits and offset; Searchers which returns list of hits in the top level in the result must return at least hits number of hits (or if impossible; all that are available), starting at the given offset. In addition, searchers are allowed to return any number of meta hits (although this number is expected to be low). For hits contained in nested hit groups, the concept of a window defined by hits and offset is not well defined and does not apply.

      Error handling in searchers:

      • Unexpected events: Throw any RuntimeException. This query will fail with the exception message, and the error will be logged
      • Expected events: Create (new Result(Query, ErrorMessage) or add result.setErrorIfNoOtherErrors(ErrorMessage) an error message to the Result.
      • Recoverable user errors: Add a FeedbackHit explaining the condition and how to correct it.
      Specified by:
      search in class Searcher
      Parameters:
      query - the query
      Returns:
      the result of making this query

    • fill

      public void fill(Result result, String summaryClass, Execution execution)
      Description copied from class: Searcher
      Fill hit properties with data using the given summary class. Calling this on already filled results has no cost.

      This needs to be overridden by federating searchers to contact search sources again by propagating the fill call down through the search chain, and by source searchers which talks to fill capable backends to request the data to be filled. Other searchers do not need to override this.

      Overrides:
      fill in class Searcher
      Parameters:
      result - the result to fill
      summaryClass - the name of the collection of fields to fetch the values of, or null to use the default

    • fillHits

      protected VespaBackEndSearcher.FillHitsResult fillHits(Result result, DocsumPacket[] packets, String summaryClass)
      Fills the hits.
      Returns:
      the number of hits that we did not return data for, and an optional error message. when things are working normally we return 0.

    • getDocsumDefinitionSet

      protected DocsumDefinitionSet getDocsumDefinitionSet(Query query)

    • shutDown

      public void shutDown()