Package org.apache.solr.common.cloud

Class CompositeIdRouter

java.lang.Object
org.apache.solr.common.cloud.DocRouter
org.apache.solr.common.cloud.HashBasedRouter
org.apache.solr.common.cloud.CompositeIdRouter
public class CompositeIdRouter extends HashBasedRouter
CompositeIdRouter partitions ids based on a SEPARATOR, hashes each partition and merges the hashes together to map the id to a slice. This allows bucketing of like groups of ids.

Allows basic separation split between 32 bits as example given below, or using bitsSeparator can specify exact bits 

 Example inputs:
 user!uniqueid
 app!user!uniqueid
 user/4!uniqueid
 app/2!user/4!uniqueid
Let's say you had a set of records you want to index together such as a contact in a database, using a prefix of contact!contactid would allow all contact ids to be bucketed together. 
 An Example:
 If the id "contact!0000000KISS is passed 😘
 Take "contact"" and hash it with murmurhash3_x86_32
 result: -541354036
 bits: 11011111101110111001011111001100

 Take 0000000KISS and hash it with murmurhash3_x86_32
 result: 2099700320
 bits: 01111101001001101110001001100000

 Now we take the bits and apply a mask, since this is 32 bits the mask is the first 16 bits or the last 16 bits
 So uppermask = 0xFFFF0000  11111111111111110000000000000000
 So we bitwise AND to get half the original hash and only the upper 16 bits for 00T
 11011111101110111001011111001100
 11111111111111110000000000000000
 ________________________________
 11011111101110110000000000000000

 lowermask = 0x0000FFFF 00000000000000001111111111111111
 So we bitwise AND and get the lower 16 bits of the original hash for 0000000KISS
 01111101001001101110001001100000
 00000000000000001111111111111111
 ________________________________
 00000000000000001110001001100000

 Now we combine the hashes with a bitwise OR
 11011111101110110000000000000000
 00000000000000001110001001100000
 ________________________________
 11011111101110111110001001100000

 11011111101110111110001001100000 is the hash we return, bucketing the suffixed by prefix type prefix!suffix

  • Field Details

    • NAME

      public static final String NAME
      See Also:

    • SEPARATOR

      public static final char SEPARATOR
      This character separates a composite ID into a leading route key and the rest.

      Importantly, it's also used at the end of a provided route key parameter (which appears in many places) to designate a hash range which translates to a list of slices. If a route key does not end with this character, then semantically the key points to a single slice that holds a doc with that ID.

      See Also:

    • bitsSeparator

      public static final int bitsSeparator
      See Also:

  • Constructor Details

    • CompositeIdRouter

      public CompositeIdRouter()

  • Method Details

    • getRouteKeyWithSeparator

      public int getRouteKeyWithSeparator(byte[] id, int idOffset, int idLength)
      Parse out the route key from id up to and including the SEPARATOR, returning its length. If no route key is detected then 0 is returned.

    • getRouteKeyNoSuffix

      public String getRouteKeyNoSuffix(String id)
      Parse out the route key from id. It will not have the "bits" suffix or separator, if present. If there is no route key found then null is returned.

    • sliceHash

      public int sliceHash(String id, SolrInputDocument doc, SolrParams params, DocCollection collection)
      Overrides:
      sliceHash in class HashBasedRouter

    • getTargetSlice

      public Slice getTargetSlice(String id, SolrInputDocument sdoc, String route, SolrParams params, DocCollection collection)
      Description copied from class: DocRouter
      Returns the Slice that the document should reside on, or null if there is not enough information
      Overrides:
      getTargetSlice in class HashBasedRouter

    • keyHashRange

      public DocRouter.Range keyHashRange(String routeKey)
      Get Range for a given CompositeId based route key
      Parameters:
      routeKey - to return Range for
      Returns:
      Range for given routeKey

    • getSearchRangeSingle

      public DocRouter.Range getSearchRangeSingle(String shardKey, SolrParams params, DocCollection collection)
      Description copied from class: DocRouter
      This method is consulted to determine what search range (the part of the hash ring) should be queried for a request when an explicit shards' parameter was not used. This method only accepts a single shard key (or null).
      Overrides:
      getSearchRangeSingle in class DocRouter

    • getSearchSlicesSingle

      public Collection<Slice> getSearchSlicesSingle(String shardKey, SolrParams params, DocCollection collection)
      Description copied from class: DocRouter
      This method is consulted to determine what slices should be queried for a request when an explicit shards' parameter was not used. This method only accepts a single shard key (or null). If you have a comma separated list of shard keys, call getSearchSlices
      Overrides:
      getSearchSlicesSingle in class HashBasedRouter

    • preprocessRouteKey

      protected String preprocessRouteKey(String shardKey)
      Methods accepting a route key (shard key) can have this input preprocessed by a subclass before further analysis.

    • getName

      public String getName()
      Specified by:
      getName in class DocRouter

    • partitionRangeByKey

      public List<DocRouter.Range> partitionRangeByKey(String key, DocRouter.Range range)

    • partitionRange

      public List<DocRouter.Range> partitionRange(int partitions, DocRouter.Range range)
      Description copied from class: DocRouter
      Split the range into partitions.
      Overrides:
      partitionRange in class DocRouter
      Parameters:
      partitions - number of partitions
      range - range to split