首页 > 解决方案 > Solr 8.6 中的矢量评分插件

问题描述

我正在尝试将VectorScoringPlugin升级到 Solr 8.6。在检查 Lucene 8.x 的迁移日志后,我了解到插件中使用的类 viz.CustomScoreQuery 和 CustomScoreProvider 已被弃用,相反,我们必须将 FunctionScoreQuery 与 DoubleValuesSource 一起使用。我做了很多搜索,但找不到使用上述类实现自定义记分器的任何示例。我在 java-lucene 论坛上偶然发现了这 2 个线程[thread1 , thread2],它们基本上讨论了相同的问题,并且提到的解决方案是实现一个自定义的 DoubleValuesSource 类,该类将具有自定义逻辑。下面是实现;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.lucene.analysis.payloads.PayloadHelper;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.index.PostingsEnum;
import org.apache.lucene.index.Terms;
import org.apache.lucene.index.TermsEnum;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.search.DoubleValues;
import org.apache.lucene.search.DoubleValuesSource;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.util.BytesRef;
import org.apache.solr.common.SolrException;

public class CustomDoubleValueSource extends DoubleValuesSource {

    List<Double> vector;
    private String field;
    private boolean cosine;
    double queryVectorNorm = 0;

    public CustomDoubleValueSource(String field, String Vector, boolean cosine) {
        // TODO Auto-generated constructor stub
        super();
        this.field = field;
        this.cosine = cosine;
        this.vector = new ArrayList<Double>();
        String[] vectorArray = Vector.split(",");
        for (int i = 0; i < vectorArray.length; i++) {
            double v = Double.parseDouble(vectorArray[i]);
            vector.add(v);
            if (cosine) {
                queryVectorNorm += Math.pow(v, 2.0);
            }
        }
        
        System.out.println("Vector size:"+this.vector.size());
    }

    @Override
    public boolean isCacheable(LeafReaderContext ctx) {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public DoubleValues getValues(LeafReaderContext ctx, DoubleValues scores) throws IOException {

        Terms terms = ctx.reader().terms(field);
        TermsEnum te = terms == null ? null : terms.iterator();
        
        System.out.println("Term size:"+terms.size());

        if (vector.size() != terms.size()) {
            throw new SolrException(SolrException.ErrorCode.BAD_REQUEST,
                    "indexed and input vector array must have same length");
        }

        final PostingsEnum pe = te.postings(null);
        // TODO Auto-generated method stub
        return new DoubleValues() {

            @Override
            public double doubleValue() throws IOException {
                // TODO Auto-generated method stub
                float score = 0;
                double docVectorNorm = 0;
                BytesRef text;
                while ((text = te.next()) != null) {
                    String term = text.utf8ToString();
                    float payloadValue = 0f;
                    PostingsEnum postings = te.postings(null, PostingsEnum.ALL);
                    while (postings.nextDoc() != DocIdSetIterator.NO_MORE_DOCS) {
                        int freq = postings.freq();
                        while (freq-- > 0)
                            postings.nextPosition();

                        BytesRef payload = postings.getPayload();
                        payloadValue = PayloadHelper.decodeFloat(payload.bytes, payload.offset);

                        if (cosine)
                            docVectorNorm += Math.pow(payloadValue, 2.0);
                    }

                    score = (float) (score + payloadValue * (vector.get(Integer.parseInt(term))));
                }

                if (cosine) {
                    if ((docVectorNorm == 0) || (queryVectorNorm == 0))
                        return 0f;
                    return (float) (score / (Math.sqrt(docVectorNorm) * Math.sqrt(queryVectorNorm)));
                }

                return score;
            }

            @Override
            public boolean advanceExact(int doc) throws IOException {
                // TODO Auto-generated method stub
                if (pe.docID() > doc)
                    return false;
                
                return pe.docID() == doc || pe.advance(doc) == doc;
            }
        };
    }

    @Override
    public boolean needsScores() {
        // TODO Auto-generated method stub
        return true;
    }

    @Override
    public DoubleValuesSource rewrite(IndexSearcher reader) throws IOException {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public int hashCode() {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public boolean equals(Object obj) {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public String toString() {
        // TODO Auto-generated method stub
        return null;
    }

}

我正在使用上述自定义类,如下所示;

import org.apache.lucene.queries.function.FunctionScoreQuery;
import org.apache.lucene.search.Query;
import org.apache.solr.common.SolrException;
import org.apache.solr.common.params.SolrParams;
import org.apache.solr.request.SolrQueryRequest;
import org.apache.solr.schema.FieldType;
import org.apache.solr.search.QParser;
import org.apache.solr.search.QParserPlugin;
import org.apache.solr.search.QueryParsing;
import org.apache.solr.search.SyntaxError;

public class VectorQParserPlugin extends QParserPlugin {
    @Override
    public QParser createParser(String qstr, SolrParams localParams, SolrParams params, SolrQueryRequest req) {
        return new QParser(qstr, localParams, params, req) {
            @Override
            public Query parse() throws SyntaxError {
                String field = localParams.get(QueryParsing.F);
                String vector = localParams.get("vector");
                boolean cosine = localParams.getBool("cosine", true);

                if (field == null) {
                    throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "'f' not specified");
                }

                if (vector == null) {
                    throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "vector missing");
                }
                
                System.out.println("FIELD:"+field);

                Query subQuery = subQuery(localParams.get(QueryParsing.V), null).getQuery();

                FieldType ft = req.getCore().getLatestSchema().getFieldType(field);
                
                if(ft != null) {
                    System.out.println("in here");
                    VectorQuery q = new VectorQuery(subQuery);
                    q.setQueryString(localParams.toLocalParamsString()); 
                    query = q;
                }
            
                System.out.println("QUERY:"+query);
                if (query == null) {
                    throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "Query is null");
                }

                return FunctionScoreQuery.boostByValue(query, new CustomDoubleValueSource(field, vector, cosine));

            }
        };
    }
}

此外,我将自定义 Query 实现升级到特定于 8.6 的版本,以避免Query 没有实现 createWieght错误。

下面是 VectorQuery 的实现;

import java.io.IOException;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.search.ConstantScoreScorer;
import org.apache.lucene.search.ConstantScoreWeight;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreMode;
import org.apache.lucene.search.Scorer;
import org.apache.lucene.search.Weight;
public class VectorQuery extends Query {
    String queryStr = "";
    Query q;
    public VectorQuery(Query subQuery) {
        this.q = subQuery;
    }
    
    public void setQueryString(String queryString){
        this.queryStr = queryString;
    }

    public Weight createWeight(IndexSearcher searcher, ScoreMode needsScores, float boost) throws IOException {
        Weight w;
        if(q == null){
            w =  new ConstantScoreWeight(this, boost) {
                @Override
                public Scorer scorer(LeafReaderContext context) throws IOException {
                    return new ConstantScoreScorer(this, score(), needsScores, DocIdSetIterator.all(context.reader().maxDoc()));
                }

                @Override
                public boolean isCacheable(LeafReaderContext ctx) {
                    // TODO Auto-generated method stub
                    return false;
                }
            };
        }else{
            w = searcher.createWeight(q, needsScores, boost);
        }
        return w;
    }

    @Override
    public String toString(String field) {
        return queryStr;
    }

    @Override
    public boolean equals(Object other) {
        return sameClassAs(other) &&
                queryStr.equals(other.toString());
    }

    @Override
    public int hashCode() {
        return classHash() ^ queryStr.hashCode();
    }

}

我添加了打印语句来检查执行流程,并调用了 CustomDoubleValueSource 类。下面是日志的截图。

在此处输入图像描述

但是执行流程没有到达 getValues 方法。我收到以下错误;

2020-10-21 16:55:09.578 ERROR (qtp1962826816-19) [   x:example_vector] o.a.s.s.HttpSolrCall null:java.lang.NullPointerException
        at org.apache.lucene.queries.function.FunctionScoreQuery$MultiplicativeBoostValuesSource.getValues(FunctionScoreQuery.java:261)
        at org.apache.lucene.queries.function.FunctionScoreQuery$FunctionScoreWeight.scorer(FunctionScoreQuery.java:224)
        at org.apache.lucene.search.Weight.bulkScorer(Weight.java:181)
        at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:658)
        at org.apache.lucene.search.IndexSearcher.search(IndexSearcher.java:445)
        at org.apache.solr.search.SolrIndexSearcher.buildAndRunCollectorChain(SolrIndexSearcher.java:208)
        at org.apache.solr.search.SolrIndexSearcher.getDocListNC(SolrIndexSearcher.java:1593)
        at org.apache.solr.search.SolrIndexSearcher.getDocListC(SolrIndexSearcher.java:1410)
        at org.apache.solr.search.SolrIndexSearcher.search(SolrIndexSearcher.java:593)
        at org.apache.solr.handler.component.QueryComponent.doProcessUngroupedSearch(QueryComponent.java:1513)
        at org.apache.solr.handler.component.QueryComponent.process(QueryComponent.java:403)
        at org.apache.solr.handler.component.SearchHandler.handleRequestBody(SearchHandler.java:331)
        at org.apache.solr.handler.RequestHandlerBase.handleRequest(RequestHandlerBase.java:214)
        at org.apache.solr.core.SolrCore.execute(SolrCore.java:2606)
        at org.apache.solr.servlet.HttpSolrCall.execute(HttpSolrCall.java:812)
        at org.apache.solr.servlet.HttpSolrCall.call(HttpSolrCall.java:588)
        at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:415)
        at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:345)
        at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1596)
        at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:545)
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
        at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:590)
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
        at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:235)
        at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1610)
        at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
        at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1300)
        at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188)
        at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:485)
        at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1580)
        at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186)
        at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1215)
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
        at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:221)
        at org.eclipse.jetty.server.handler.InetAccessHandler.handle(InetAccessHandler.java:177)
        at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:146)
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
        at org.eclipse.jetty.rewrite.handler.RewriteHandler.handle(RewriteHandler.java:322)
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
        at org.eclipse.jetty.server.Server.handle(Server.java:500)
        at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:383)
        at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:547)
        at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:375)
        at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:273)
        at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311)
        at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:103)
        at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:117)
        at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:806)
        at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:938)
        at java.lang.Thread.run(Thread.java:748)

我强烈怀疑这与 CustomDoubleValuesSource 中未实现的方法有关。我阅读了DoubleValuesSource 的java 文档,但它们不是描述性的或不包含任何示例。

感谢任何能让我前进的帮助:)

标签: javasolrlucene

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