git.m6w6.name Git - awesomized/libmemcached/blob - docs/memcached_behavior.pod

   1 =head1 NAME
   2
   3 memcached_behavior_get memcached_behavior_set
   4
   5 =head1 LIBRARY
   6
   7 C Client Library for memcached (libmemcached, -lmemcached)
   8
   9 =head1 SYNOPSIS
  10
  11   #include <memcached.h>
  12
  13   unsigned long long
  14     memcached_behavior_get (memcached_st *ptr,
  15                             memcached_behavior flag);
  16
  17   memcached_return
  18     memcached_behavior_set (memcached_st *ptr,
  19                             memcached_behavior flag,
  20                             void *data);
  21
  22 =head1 DESCRIPTION
  23
  24 libmemcached(3) behavior can be modified by use memcached_behavior_set().
  25 Default behavior is the library strives to be quick and accurate. Some
  26 behavior, while being faster, can also result in not entirely accurate
  27 behavior (for instance, memcached_set() will always respond with
  28 C<MEMCACHED_SUCCESS>).
  29
  30 memcached_behavior_get() takes a behavior flag and returns whether or not
  31 that behavior is currently enabled in the client.
  32
  33 memcached_behavior_set() changes the value of a particular option of the
  34 client. It takes both a flag (listed below) and a value. For simple on or
  35 off options you just need to pass in a value of 1. Calls to
  36 memcached_behavior_set() will flush and reset all connections.
  37
  38 =over 4
  39
  40 =item MEMCACHED_BEHAVIOR_REPLICAS
  41
  42 By default libmemcached(3) stores data in just one node of the cluster. Setting this value
  43 to a number will cause that number of copies to be kept. The value must be greater then
  44 zero, and must be at most the same value as the number of hosts in the cluster.
  45
  46 =item MEMCACHED_BEHAVIOR_NO_BLOCK
  47
  48 Causes libmemcached(3) to use asychronous IO. This is the fastest transport
  49 available for storage functions. For read operations it is currently
  50 similar in performance to the non-blocking method (this is being
  51 looked into).
  52
  53 =item MEMCACHED_BEHAVIOR_TCP_NODELAY
  54
  55 Turns on the no-delay feature for connecting sockets (may be faster in some
  56 environments).
  57
  58 =item MEMCACHED_BEHAVIOR_HASH
  59
  60 Makes the default hashing algorithm for keys use MD5. The value can be set to either MEMCACHED_HASH_DEFAULT, MEMCACHED_HASH_MD5, MEMCACHED_HASH_CRC, MEMCACHED_HASH_FNV1_64, MEMCACHED_HASH_FNV1A_64, MEMCACHED_HASH_FNV1_32, MEMCACHED_HASH_FNV1A_32, MEMCACHED_HASH_KETAMA. The behavior for all hashes but MEMCACHED_HASH_DEFAULT is identitical to the Java driver written by Dustin Sallings.
  61
  62 =item MEMCACHED_BEHAVIOR_DISTRIBUTION
  63
  64 Using this you can enable different means of distributing values to servers.
  65 The default method is MEMCACHED_DISTRIBUTION_MODULA. You can enable
  66 consistent hashing by setting MEMCACHED_DISTRIBUTION_CONSISTENT.
  67 Consistent hashing delivers better distribution and allows servers to be
  68 added to the cluster with minimal cache losses.
  69
  70 =item MEMCACHED_BEHAVIOR_CACHE_LOOKUPS
  71
  72 Memcached can cache named lookups so that DNS lookups are made only once.
  73
  74 =item MEMCACHED_BEHAVIOR_SUPPORT_CAS
  75
  76 Support CAS operations (this is not enabled by default at this point in the server since it imposes a slight performance penalty).
  77
  78 =item MEMCACHED_BEHAVIOR_POLL_TIMEOUT
  79
  80 Modify the timeout value that is used by poll(). The default value is -1. An signed int pointer must be passed to memcached_behavior_set() to change this value. For memcached_behavior_get() a signed int value will be cast and returned as the unsigned long long.
  81
  82 =item MEMCACHED_BEHAVIOR_USER_DATA
  83
  84 This allows you to store a pointer to a specifc piece of data. This can be
  85 retrieved from inside of memcached_fetch_execute(). Cloning a memcached_st
  86
  87 will copy the pointer to the clone. This was deprecated in 0.14 in favor
  88 of memcached_callback_set(3). This will be removed in 0.15.
  89
  90 =item MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
  91
  92 Enabling buffered IO causes commands to "buffer" instead of being sent. Any
  93 action that gets data causes this buffer to be be sent to the remote
  94 connection. Quiting the connection or closing down the connection will also
  95 cause the buffered data to be pushed to the remote connection.
  96
  97 =item MEMCACHED_BEHAVIOR_VERIFY_KEY
  98
  99 Enabling this will cause libmemcached(3) to test all keys to verify that they
 100 are valid keys.
 101
 102 =item MEMCACHED_BEHAVIOR_SORT_HOSTS
 103
 104 Enabling this will cause hosts that are added to be placed in the host list in
 105 sorted order. This will defeat consisten hashing.
 106
 107 =item MEMCACHED_BEHAVIOR_CONNECT_TIMEOUT
 108
 109 In non-blocking mode this changes the value of the timeout during socket
 110 connection.
 111
 112 =back
 113
 114 =head1 RETURN
 115
 116 memcached_behavior_get() returns either the current value of the get, or 0
 117 or 1 on simple flag behaviors (1 being enabled). memcached_behavior_set()
 118 returns whether or not the behavior was enabled.
 119
 120 =head1 HOME
 121
 122 To find out more information please check:
 123 L<http://tangent.org/552/libmemcached.html>
 124
 125 =head1 AUTHOR
 126
 127 Brian Aker, E<lt>brian@tangent.orgE<gt>
 128
 129 =head1 SEE ALSO
 130
 131 memcached(1) libmemcached(3) memcached_strerror(3)
 132
 133 =cut
 134