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 versionField, a comma-delimited list of fields to check for version numbers. 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 values within the fields as specified by the comma-delimited versionField property are checked, and if in the existing document the values for all fields are not less than the field values 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(s) of the request parameter(s) which becomes mandatory for all Delete By Id commands. Like versionField, deleteVersionParam is comma-delimited. For each of the params given, it specifies the document version associated with the delete, where the index matches versionField. For example, if versionField was set to 'a,b' and deleteVersionParam was set to 'p1,p2', p1 should give the version for field 'a' and p2 should give the version for field 'b'. If the versions specified using these params are 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 fields corresponding to the fields listed in 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.
    • supportMissingVersionOnOldDocs - This boolean parameter defaults to false, but if set to true allows any documents written *before* this feature is enabled and which are missing the versionField to be overwritten.
    • tombstoneConfig - a list of field names to values to add to the created tombstone document. In general is not a good idea to populate tombsone documents with anything other than the minimum required fields so that it doean't match queries