SolrCloud

The SolrCloud search module brokers all communication with a SolrCloud cluster. See also documentation on the Solr[Solr platform] for further background.

Setup

To add SolrCloud search connectors to a Maven project, you must add this dependency to your project’s pom.xml file:

<dependency>
    <groupId>twigkit</groupId>
    <artifactId>twigkit.solr.cloud</artifactId>
    <version>${project.parent.version}</version>
</dependency>

Usage

Assuming you have added the correct dependencies to your project (see above), the Solr platform configuration can be accessed by pointing to it in the search:platform tag. In this case the platform is placed in a variable named platform using the var attribute, and points to a platform configuration in ../conf/platforms/solr/solr.conf:

<search:platform var="platform" conf="platforms.solr"></search:platform>

platforms/solr/solr.conf

In this example platform configuration, we set some general settings for the platform:

name: twigkit.search.solr.cloud.SolrCloud
resultIDField: id
defaultQuery: *:*
zookeeper-host: cld-dapp-slr61:2181,cld-dapp-slr62:2181,cld-dapp-slr63:2181
defaultFacets: age,weight
default-collection: mycollection

Required attributes

zookeeper-host (java.lang.String)
The client endpoint of the zookeeper quorum containing the cloud state. The full specification for this string is one or more comma separated HOST:PORT values, followed by an optional chroot value that starts with a forward slash. Using a chroot allows multiple applications to coexist in one ensemble. For full details, see the ZooKeeper documentation.

Here are some examples:

  • host1:2181

  • host1:2181,host2:2181,host3:2181/mysolrchroot

  • zoo1.example.com:2181,zoo2.example.com:2181,zoo3.example.com:2181

Optional attributes

groupField (java.lang.String)
Setting this enables Solr Result Grouping or Field Collapsing on the given field.

backwardsCompatible (java.lang.Boolean)
For Solr 1.x (for example, 1.4) set backwardsCompatible to true.
Default: false

ignoreAppliedFilters (java.lang.Boolean)
If this is set to false, facet filters that have already been applied to the Query are added to the list of filters for the facet.
Default: true

requestMethod (java.lang.String)
Which HTTP request method to use (GET or POST).

highlighting (java.lang.Boolean)
Whether to enable hit highlighting (hl parameter) in Solr.
Default: true

max-query-resend-attempts (java.lang.Integer)
The maximum number of times a query is re-sent after a ZooKeeper session expires.
Default: 1

Attributes shared across platforms

default-collection (java.lang.String)
Specifies the default Solr collection for the request.

name (java.lang.String)
The display name of this Platform instance. Used for identifying different platforms in the user interface.

aliases (java.lang.String)
Manage mappings from field names to aliases (use a comma-separated list). All references to the field (via this platform) in results, facets, filters, and query strings are mapped. For example, to refer to a field in the index named firstnamelastname as name and countryofresidence as country, use these mappings: aliases="firstnamelastname=name,countryofresidence=country"

defaultQuery (java.lang.String)
Default query to use when none is specified.

defaultFacets (java.lang.String)
Default facets to request when none are specified. This is a comma separated list.

spellCheck (java.lang.Boolean)
Spellcheck the Query term if supported by the Platform.
Default: true

expandQuery (java.lang.Boolean)
Apply advanced linguistics such as stemming or lemmatization if supported by the Platform.
Default: true

autoCorrect (java.lang.Boolean)
Whether to auto-correct and resubmit futile queries (queries with zero results).
Default: true

fileTypeField (java.lang.String)
Set which field contains information about file type (mime type).

resultIDField (java.lang.String)
Set which field represents the unique identifier for a given result. Should correspond to the <uniqueKey> element in the Solr schema.xml.

pageLimit (java.lang.Long)
A limitation to which page the platform will offset.

Use of the fields parameter in the Appkit query tag with the SolrCloud platform

By default, on all platforms, if the optional fields parameter is not used in the <search:query> tag, all fields will be returned in the response. This is not the case however with the SolrCloud platform. On this platform, if the fields parameter is omitted no fields will be returned in the response. This is to work around an issue identified with the SolrCloud platform that does not allow fields given by Appkit to be overridden by those defined in an invariants section of the SolrCloud request handler. To return all fields in the case, the fields parameter would must contain a wildcard character, fields="*".