如何 select 分片搜索查询？

Question

我最近实现了 ShardIdentifierProvider。它工作正常。但是如何确保它只使用一个共享进行查询？

public class SiteIdAsShardIdProvider extends ShardIdentifierProviderTemplate {

@Override
protected Set<String> loadInitialShardNames(Properties properties, BuildContext buildContext) {
    ServiceManager serviceManager = buildContext.getServiceManager();
    SessionFactory sessionFactory = serviceManager.requestService(HibernateSessionFactoryServiceProvider.class, buildContext);
    Session session = sessionFactory.openSession();
    try {
        @SuppressWarnings("unchecked")
        List<String> ids = session.createSQLQuery("select cast(id as CHAR(3)) from website").list();
        return new HashSet<>(ids);
    } finally {
        session.close();
    }
}

@Override
public String getShardIdentifier(Class<?> entityType, Serializable id, String idAsString, Document document) {
    return document.getFieldable("siteId").stringValue();
}
}

Answer 1

查询时的分片选择由自定义过滤器控制。

有关详细信息和示例，请参阅 "5.3.1. Using filters in a sharded environment"。

Answer 2

创建您自己的自定义过滤器并覆盖 getShardIdentifiersForQuery 应该可以解决问题。这是与 the documentation 中的内容大致相同的内容，但具有 ShardIdentifierProviderTemplate:

@Override
public Set<String> getShardIdentifiersForQuery(FullTextFilterImplementor[] filters) {
    FullTextFilter filter = getFilterByName( filters, "customer" );
    if ( filter == null ) {
        return getAllShardIdentifiers();
    }
    else {
        Set<String> result = new HashSet<>();
        result.add( filter.getParameter( "customerID" ) );
        return result;
    }
}

private FullTextFilter getFilterByName(FullTextFilterImplementor[] filters, String name) {
    for ( FullTextFilterImplementor filter: filters ) {
        if ( filter.getName().equals( name ) ) {
            return filter;
        }
    }
    return null;
}

我创建了一张票来更新文档：https://hibernate.atlassian.net/browse/HSEARCH-2513

如何 select 分片搜索查询？

How to select shard for search query?

hibernate-search