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   uint64_t
  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                             uint64_t 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_NO_BLOCK
  41
  42 Causes libmemcached(3) to use asychronous IO. This is the fastest transport
  43 available for storage functions. For read operations it is currently
  44 similar in performance to the non-blocking method (this is being
  45 looked into).
  46
  47 =item MEMCACHED_BEHAVIOR_SND_TIMEOUT
  48
  49 This sets the microsecond behavior of the socket against the SO_SNDTIMEO flag.
  50 In cases where you cannot use non-blocking IO this will allow you to still have
  51 timeouts on the sending of data.
  52
  53 =item MEMCACHED_BEHAVIOR_RCV_TIMEOUT
  54
  55 This sets the microsecond behavior of the socket against the SO_RCVTIMEO flag.
  56 In cases where you cannot use non-blocking IO this will allow you to still have
  57 timeouts on the reading of data.
  58
  59 =item MEMCACHED_BEHAVIOR_TCP_NODELAY
  60
  61 Turns on the no-delay feature for connecting sockets (may be faster in some
  62 environments).
  63
  64 =item MEMCACHED_BEHAVIOR_HASH
  65
  66 Makes the default hashing algorithm for keys use MD5. The value can be set
  67 to either MEMCACHED_HASH_DEFAULT, MEMCACHED_HASH_MD5, MEMCACHED_HASH_CRC, MEMCACHED_HASH_FNV1_64, MEMCACHED_HASH_FNV1A_64, MEMCACHED_HASH_FNV1_32, and MEMCACHED_HASH_FNV1A_32. The behavior for all hashes but MEMCACHED_HASH_DEFAULT is identitical to the Java driver written by Dustin Sallings.
  68
  69 =item MEMCACHED_BEHAVIOR_DISTRIBUTION
  70
  71 Using this you can enable different means of distributing values to servers.
  72 The default method is MEMCACHED_DISTRIBUTION_MODULA. You can enable
  73 consistent hashing by setting MEMCACHED_DISTRIBUTION_CONSISTENT.
  74 Consistent hashing delivers better distribution and allows servers to be
  75 added to the cluster with minimal cache losses. Currently
  76 MEMCACHED_DISTRIBUTION_CONSISTENT is an alias for the value
  77 MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA.
  78
  79 =item MEMCACHED_BEHAVIOR_CACHE_LOOKUPS
  80
  81 Memcached can cache named lookups so that DNS lookups are made only once.
  82
  83 =item MEMCACHED_BEHAVIOR_SUPPORT_CAS
  84
  85 Support CAS operations (this is not enabled by default at this point in the server since it imposes a slight performance penalty).
  86
  87 =item MEMCACHED_BEHAVIOR_KETAMA
  88
  89 Sets the default distribution to MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA
  90 and the hash to MEMCACHED_HASH_MD5.
  91
  92 =item MEMCACHED_BEHAVIOR_KETAMA_WEIGHTED
  93
  94 Sets the default distribution to MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA with the weighted support.
  95 and the hash to MEMCACHED_HASH_MD5.
  96
  97 =item MEMCACHED_BEHAVIOR_KETAMA_HASH
  98
  99 Sets the hashing algorithm for host mapping on continuum. The value can be set
 100 to either MEMCACHED_HASH_DEFAULT, MEMCACHED_HASH_MD5, MEMCACHED_HASH_CRC, MEMCACHED_HASH_FNV1_64, MEMCACHED_HASH_FNV1A_64, MEMCACHED_HASH_FNV1_32, and MEMCACHED_HASH_FNV1A_32.
 101
 102 =item MEMCACHED_BEHAVIOR_POLL_TIMEOUT
 103
 104 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.
 105
 106 =item MEMCACHED_BEHAVIOR_USER_DATA
 107
 108 This allows you to store a pointer to a specifc piece of data. This can be
 109 retrieved from inside of memcached_fetch_execute(). Cloning a memcached_st
 110
 111 will copy the pointer to the clone. This was deprecated in 0.14 in favor
 112 of memcached_callback_set(3). This will be removed in 0.15.
 113
 114 =item MEMCACHED_BEHAVIOR_BUFFER_REQUESTS
 115
 116 Enabling buffered IO causes commands to "buffer" instead of being sent. Any
 117 action that gets data causes this buffer to be be sent to the remote
 118 connection. Quiting the connection or closing down the connection will also
 119 cause the buffered data to be pushed to the remote connection.
 120
 121 =item MEMCACHED_BEHAVIOR_VERIFY_KEY
 122
 123 Enabling this will cause libmemcached(3) to test all keys to verify that they
 124 are valid keys.
 125
 126 =item MEMCACHED_BEHAVIOR_SORT_HOSTS
 127
 128 Enabling this will cause hosts that are added to be placed in the host list in
 129 sorted order. This will defeat consisten hashing.
 130
 131 =item MEMCACHED_BEHAVIOR_CONNECT_TIMEOUT
 132
 133 In non-blocking mode this changes the value of the timeout during socket
 134 connection.
 135
 136 =item MEMCACHED_BEHAVIOR_BINARY_PROTOCOL
 137
 138 Enable the use of the binary protocol. Please note that you cannot toggle
 139 this flag on an open connection.
 140
 141 =item MEMCACHED_BEHAVIOR_SERVER_FAILURE_LIMIT
 142
 143 Set this value to enable the server be removed after continuous MEMCACHED_BEHAVIOR_SERVER_FAILURE_LIMIT
 144 times connection failure.
 145
 146 =back
 147
 148 =head1 RETURN
 149
 150 memcached_behavior_get() returns either the current value of the get, or 0
 151 or 1 on simple flag behaviors (1 being enabled). memcached_behavior_set()
 152 returns failure or success.
 153
 154 =head1 NOTES
 155
 156 memcached_behavior_set() in version .17 was changed from taking a pointer
 157 to data value, to taking a uin64_t.
 158
 159 =head1 HOME
 160
 161 To find out more information please check:
 162 L<http://tangent.org/552/libmemcached.html>
 163
 164 =head1 AUTHOR
 165
 166 Brian Aker, E<lt>brian@tangent.orgE<gt>
 167
 168 =head1 SEE ALSO
 169
 170 memcached(1) libmemcached(3) memcached_strerror(3)
 171
 172 =cut
 173