org.apache.solr.update.processor

Class DocBasedVersionConstraintsProcessorFactory

  • All Implemented Interfaces:
    UpdateRequestProcessorFactory.RunAlways, NamedListInitializedPlugin, SolrCoreAware


    public class DocBasedVersionConstraintsProcessorFactory
    extends UpdateRequestProcessorFactory
    implements SolrCoreAware, UpdateRequestProcessorFactory.RunAlways

    This Factory generates an UpdateProcessor that helps to enforce Version constraints on documents based on per-document version numbers using a configured name of a versionField. It should be configured on the "default" update processor somewhere before the DistributedUpdateProcessorFactory. As an example, see the solrconfig.xml that the tests use: solr/core/src/test-files/solr/collection1/conf/solrconfig-externalversionconstraint.xml

    When documents are added through this processor, if a document with the same unique key already exists in the collection, then the value of the versionField in the existing document is not less then the field value in the new document then the new document is rejected with a 409 Version Conflict error.

    In addition to the mandatory versionField init param, two additional optional init params affect the behavior of this factory:

    • deleteVersionParam - This string parameter controls whether this processor will intercept and inspect Delete By Id commands in addition to adding documents. If specified, then the value will specify the name of a request paramater which becomes mandatory for all Delete By Id commands. This param must then be used to specify the document version associated with the delete. If the version specified using this param is not greater then the value in the versionField for any existing document, then the delete will fail with a 409 Version Conflict error. When using this param, Any Delete By Id command with a high enough document version number to succeed will be internally converted into an Add Document command that replaces the existing document with a new one which is empty except for the Unique Key and versionField to keeping a record of the deleted version so future Add Document commands will fail if their "new" version is not high enough.
    • ignoreOldUpdates - This boolean parameter defaults to false, but if set to true causes any update with a document version that is not great enough to be silently ignored (and return a status 200 to the client) instead of generating a 409 Version Conflict error.