Package org.apache.solr.common.cloud

Class Aliases

java.lang.Object
org.apache.solr.common.cloud.Aliases
public class Aliases extends Object
Holds collection aliases -- virtual collections that point to one or more other collections. We might add other types of aliases here some day. Immutable.

  • Field Details

    • EMPTY

      public static final Aliases EMPTY
      An empty, minimal Aliases primarily used to support the non-cloud solr use cases. Not normally useful in cloud situations where the version of the node needs to be tracked even if all aliases are removed. The -1 version makes it subordinate to any real version, and furthermore we never "set" this EMPTY instance into ZK.

  • Method Details

    • forEachAlias

      public void forEachAlias(BiConsumer<String,List<String>> consumer)

    • size

      public int size()

    • fromJSON

      public static Aliases fromJSON(byte[] bytes, int zNodeVersion)
      Create an instance from the JSON bytes read from zookeeper. Generally this should only be done by a ZkStateReader.
      Parameters:
      bytes - The bytes read via a getData request to zookeeper (possibly null)
      zNodeVersion - the version of the data in zookeeper that this instance corresponds to
      Returns:
      A new immutable Aliases object

    • toJSON

      public byte[] toJSON()
      Serialize our state.

    • convertMapOfCommaDelimitedToMapOfList

      public static Map<String,List<String>> convertMapOfCommaDelimitedToMapOfList(Map<String,String> collectionAliasMap)

    • convertMapOfListToMapOfCommaDelimited

      public static Map<String,String> convertMapOfListToMapOfCommaDelimited(Map<String,List<String>> collectionAliasMap)

    • getZNodeVersion

      public int getZNodeVersion()

    • getCollectionAliasMap

      public Map<String,String> getCollectionAliasMap()
      Get a map similar to the JSON data as stored in zookeeper. Callers may prefer use of getCollectionAliasListMap() instead, if collection names will be iterated.
      Returns:
      an unmodifiable Map of collection aliases mapped to a comma delimited string of the collection(s) the alias maps to. Does not return null.

    • getCollectionAliasListMap

      public Map<String,List<String>> getCollectionAliasListMap()
      Get a fully parsed map of collection aliases.
      Returns:
      an unmodifiable Map of collection aliases mapped to a list of the collection(s) the alias maps to. Does not return null.

    • getCollectionAliasProperties

      public Map<String,String> getCollectionAliasProperties(String alias)
      Returns an unmodifiable Map of properties for a given alias. This method will never return null.
      Parameters:
      alias - the name of an alias also found as a key in getCollectionAliasListMap()
      Returns:
      The properties for the alias (possibly empty).

    • resolveAliases

      public List<String> resolveAliases(String aliasName)
      List the collections associated with a particular alias. One level of alias indirection is supported (alias to alias to collection). Such indirection may be deprecated in the future, use with caution.
      Returns:
      An unmodifiable list of collections names that the input alias name maps to. If there are none, the input is returned.

    • hasAlias

      public boolean hasAlias(String aliasName)
      Returns true if an alias is defined, false otherwise.

    • isRoutedAlias

      public boolean isRoutedAlias(String aliasName)
      Returns true if an alias exists and is a routed alias, false otherwise.

    • resolveSimpleAlias

      public String resolveSimpleAlias(String aliasName) throws SolrException
      Resolve an alias that points to a single collection. One level of alias indirection is supported.
      Parameters:
      aliasName - alias name
      Returns:
      original name if there's no such alias, or a resolved name. If an alias points to more than 1 collection (directly or indirectly) an exception is thrown
      Throws:
      SolrException - if either direct or indirect alias points to more than 1 name.

    • resolveSimpleAliasGivenAliasMap

      public static String resolveSimpleAliasGivenAliasMap(Map<String,List<String>> collectionAliasListMap, String aliasName) throws SolrException
      Throws:
      SolrException
      NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

    • resolveAliasesGivenAliasMap

      public static List<String> resolveAliasesGivenAliasMap(Map<String,List<String>> collectionAliasListMap, String aliasName)
      NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

    • cloneWithCollectionAlias

      public Aliases cloneWithCollectionAlias(String alias, String collections)
      Creates a new Aliases instance with the same data as the current one but with a modification based on the parameters.

      Note that the state in zookeeper is unaffected by this method and the change must still be persisted via ZkStateReader.AliasesManager#applyModificationAndExportToZk(UnaryOperator)

      Parameters:
      alias - the alias to update, must not be null
      collections - the comma separated list of collections for the alias, null to remove the alias

    • cloneWithRename

      public Aliases cloneWithRename(String before, String after) throws SolrException
      Rename an alias. This performs a "deep rename", which changes also the second-level alias lists. Renaming routed aliases is not supported.

      Note that the state in zookeeper is unaffected by this method and the change must still be persisted via ZkStateReader.AliasesManager#applyModificationAndExportToZk(UnaryOperator)

      Parameters:
      before - previous alias name, must not be null
      after - new alias name. If this is null then it's equivalent to calling cloneWithCollectionAlias(String, String) with the second argument set to null, ie. removing an alias.
      Returns:
      new instance with the renamed alias
      Throws:
      SolrException - when either before or after is empty, or the before name is a routed alias

    • cloneWithCollectionAliasProperties

      public Aliases cloneWithCollectionAliasProperties(String alias, String propertiesKey, String propertiesValue)
      Set the value for some properties on a collection alias. This is done by creating a new Aliases instance with the same data as the current one but with a modification based on the parameters.

      Note that the state in zookeeper is unaffected by this method and the change must still be persisted via ZkStateReader.AliasesManager#applyModificationAndExportToZk(UnaryOperator)

      Parameters:
      alias - the alias to update
      propertiesKey - the key for the properties
      propertiesValue - the properties to add/replace, null to remove the key.
      Returns:
      An immutable copy of the aliases with the new properties.

    • cloneWithCollectionAliasProperties

      public Aliases cloneWithCollectionAliasProperties(String alias, Map<String,String> properties) throws SolrException
      Set the values for some properties keys on a collection alias. This is done by creating a new Aliases instance with the same data as the current one but with a modification based on the parameters.

      Note that the state in zookeeper is unaffected by this method and the change must still be persisted via ZkStateReader.AliasesManager#applyModificationAndExportToZk(UnaryOperator)

      Parameters:
      alias - the alias to update
      properties - the properties to add/replace, null values in the map will remove the key.
      Returns:
      An immutable copy of the aliases with the new properties.
      Throws:
      SolrException

    • toString

      public String toString()
      Overrides:
      toString in class Object