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   1 # Bugs, Known Issues and Insufficiencies
   2
   3 ## libhashkit
   4
   5 libhashkit is not usable for general purpose hashing, because it is geared to
   6 usage by libmemcached.
   7
   8 ### MurMur
   9
  10 Hashkit's MurMur/MurMur3 are limited to the lower 32 bits.
  11
  12 ### crc32
  13
  14 Commit "[More Hashing methods](https://github.com/m6w6/libmemcached/commits/1207354f)"
  15 from October 2007 first released in v0.8, which main intention seems to have
  16 been to add FNV1 hash algos, changed the result of the crc32 hash to only its
  17 upper 16 bits sans MSB, without any additional comment.
  18
  19 The implementations referred to in the file header (Postgres and BSD)
  20 do not exhibit this behavior.
  21
  22 A [bug report](https://bugs.launchpad.net/libmemcached/+bug/604178) was
  23 filed three years later on launchpad, which was marked `Won't fix` with
  24 the comment that it was for compatibility with other "drivers", which
  25 supposedly refers to other memcached client libraries.
  26
  27
  28 ## libmemcached
  29
  30 ### Replication
  31
  32 This is a somewhat badly named feature, because it **does not** provide
  33 any of the guaranties one would expect from a proper replication.
  34
  35 One can set the intended number of additional servers where data should
  36 be stored with the behavior `MEMCACHED_BEHAVIOR_NUMBER_OF_REPLICAS` and
  37 specify whether `MGET`s/`GET`s should read from a random server with
  38 `MEMCACHED_BEHAVIOR_RANDOMIZE_REPLICA_READ`. `DELETE`s will try to
  39 delete the key from all replicas.
  40
  41 The binary protocol is required and any other command is unaffected.