=head1 NAME
-memcached_behavior_get memcached_behavior_set
+memcached_behavior_get, memcached_behavior_set - Manipulate behavior
=head1 LIBRARY
memcached_behavior_get (memcached_st *ptr,
memcached_behavior flag);
- memcached_return
+ memcached_return_t
memcached_behavior_set (memcached_st *ptr,
memcached_behavior flag,
uint64_t data);
memcached_behavior_set() changes the value of a particular option of the
client. It takes both a flag (listed below) and a value. For simple on or
-off options you just need to pass in a value of 1. Calls to
+off options you just need to pass in a value of 1. Calls to
memcached_behavior_set() will flush and reset all connections.
=over 4
+=item MEMCACHED_BEHAVIOR_USE_UDP
+
+Causes libmemcached(3) to use the UDP transport when communicating
+with a memcached server. Not all I/O operations are supported
+when this behavior is enababled. The following operations will return
+C<MEMCACHED_NOT_SUPPORTED> when executed with the MEMCACHED_BEHAVIOR_USE_UDP
+enabled: memcached_version(), memcached_stat(), memcached_get(),
+memcached_get_by_key(), memcached_mget(), memcached_mget_by_key(),
+memcached_fetch(), memcached_fetch_result(), memcached_value_fetch().
+
+All other operations are supported but are executed in a 'fire-and-forget'
+mode, in which once the client has executed the operation, no attempt
+will be made to ensure the operation has been received and acted on by the
+server.
+
+libmemcached(3) does not allow TCP and UDP servers to be shared within
+the same libmemached(3) client 'instance'. An attempt to add a TCP server
+when this behavior is enabled will result in a C<MEMCACHED_INVALID_HOST_PROTOCOL>,
+as will attempting to add a UDP server when this behavior has not been enabled.
+
=item MEMCACHED_BEHAVIOR_NO_BLOCK
Causes libmemcached(3) to use asychronous IO. This is the fastest transport
-available for storage functions. For read operations it is currently
-similar in performance to the non-blocking method (this is being
-looked into).
+available for storage functions.
=item MEMCACHED_BEHAVIOR_SND_TIMEOUT
=item MEMCACHED_BEHAVIOR_HASH
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, and MEMCACHED_HASH_FNV1A_32. The behavior for all hashes but MEMCACHED_HASH_DEFAULT is identitical to the Java driver written by Dustin Sallings.
+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_JENKINS, MEMCACHED_HASH_HSIEH, and MEMCACHED_HASH_MURMUR.
+Each hash has it's advantages and it's weaknesses. If you don't know or don't care, just go with the default.
+Support for MEMCACHED_HASH_HSIEH is a compile time option that is disabled by default. To enable support for this hashing algorithm, configure and build libmemcached with the --enable-hash_hsieh.
=item MEMCACHED_BEHAVIOR_DISTRIBUTION
Using this you can enable different means of distributing values to servers.
The default method is MEMCACHED_DISTRIBUTION_MODULA. You can enable
-consistent hashing by setting MEMCACHED_DISTRIBUTION_CONSISTENT.
-Consistent hashing delivers better distribution and allows servers to be
+consistent hashing by setting MEMCACHED_DISTRIBUTION_CONSISTENT.
+Consistent hashing delivers better distribution and allows servers to be
added to the cluster with minimal cache losses. Currently
MEMCACHED_DISTRIBUTION_CONSISTENT is an alias for the value
-MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA.
+MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA.
=item MEMCACHED_BEHAVIOR_CACHE_LOOKUPS
=item MEMCACHED_BEHAVIOR_KETAMA_HASH
Sets the hashing algorithm for host mapping on continuum. 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, and MEMCACHED_HASH_FNV1A_32.
+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.
+
+=item MEMCACHED_BEHAVIOR_KETAMA_COMPAT
+
+Sets the compatibility mode. The value can be set to either
+MEMCACHED_KETAMA_COMPAT_LIBMEMCACHED (this is the default) or
+MEMCACHED_KETAMA_COMPAT_SPY to be compatible with the SPY Memcached client
+for Java.
=item MEMCACHED_BEHAVIOR_POLL_TIMEOUT
Enabling buffered IO causes commands to "buffer" instead of being sent. Any
action that gets data causes this buffer to be be sent to the remote
connection. Quiting the connection or closing down the connection will also
-cause the buffered data to be pushed to the remote connection.
+cause the buffered data to be pushed to the remote connection.
=item MEMCACHED_BEHAVIOR_VERIFY_KEY
-Enabling this will cause libmemcached(3) to test all keys to verify that they
+Enabling this will cause libmemcached(3) to test all keys to verify that they
are valid keys.
=item MEMCACHED_BEHAVIOR_SORT_HOSTS
-Enabling this will cause hosts that are added to be placed in the host list in
+Enabling this will cause hosts that are added to be placed in the host list in
sorted order. This will defeat consisten hashing.
=item MEMCACHED_BEHAVIOR_CONNECT_TIMEOUT
Enable the use of the binary protocol. Please note that you cannot toggle
this flag on an open connection.
+=item MEMCACHED_BEHAVIOR_SERVER_FAILURE_LIMIT
+
+Set this value to enable the server be removed after continuous MEMCACHED_BEHAVIOR_SERVER_FAILURE_LIMIT
+times connection failure.
+
+=item MEMCACHED_BEHAVIOR_IO_MSG_WATERMARK
+
+Set this value to tune the number of messages that may be sent before
+libmemcached should start to automatically drain the input queue. Setting
+this value to high, may cause libmemcached to deadlock (trying to send data,
+but the send will block because the input buffer in the kernel is full).
+
+=item MEMCACHED_BEHAVIOR_IO_BYTES_WATERMARK
+
+Set this value to tune the number of bytes that may be sent before
+libmemcached should start to automatically drain the input queue (need
+at least 10 IO requests sent without reading the input buffer). Setting
+this value to high, may cause libmemcached to deadlock (trying to send
+data, but the send will block because the input buffer in the kernel is full).
+
+=item MEMCACHED_BEHAVIOR_IO_KEY_PREFETCH
+
+The binary protocol works a bit different than the textual protocol in
+that a multiget is implemented as a pipe of single get-operations which
+are sent to the server in a chunk. If you are using large multigets from
+your application, you may improve the latency of the gets by setting
+this value so you send out the first chunk of requests when you hit the
+specified limit. It allows the servers to start processing the requests
+to send the data back while the rest of the requests are created and
+sent to the server.
+
+=item MEMCACHED_BEHAVIOR_NOREPLY
+
+Set this value to specify that you really don't care about the result
+from your storage commands (set, add, replace, append, prepend).
+
+=item MEMCACHED_BEHAVIOR_NUMBER_OF_REPLICAS
+
+If you just want "a poor mans HA", you may specify the numbers of
+replicas libmemcached should store of each item (on different servers).
+This replication does not dedicate certain memcached servers to store the
+replicas in, but instead it will store the replicas together with all of the
+other objects (on the 'n' next servers specified in your server list).
+
+=item MEMCACHED_BEHAVIOR_RANDOMIZE_REPLICA_READ
+
+Allows randomizing the replica reads starting point. Normally the read is
+done from primary server and in case of miss the read is done from primary
++ 1, then primary + 2 all the way to 'n' replicas. If this option is set
+on the starting point of the replica reads is randomized between the servers.
+This allows distributing read load to multiple servers with the expense of
+more write traffic.
+
+=item MEMCACHED_BEHAVIOR_CORK
+
+Enable TCP_CORK behavior. This is only available as an option Linux.
+MEMCACHED_NO_SERVERS is returned if no servers are available to test with.
+MEMCACHED_NOT_SUPPORTED is returned if we were not able to determine
+if support was available. All other responses then MEMCACHED_SUCCESS
+report an error of some sort. This behavior also enables
+MEMCACHED_BEHAVIOR_TCP_NODELAY when set.
+
+
+=item MEMCACHED_BEHAVIOR_SOCKET_SEND_SIZE
+
+Find the current size of SO_SNDBUF. A value of 0 means either an error
+occured or no hosts were available. It is safe to assume system default
+if this occurs.
+
+=item MEMCACHED_BEHAVIOR_SOCKET_RECV_SIZE
+
+Find the current size of SO_RCVBUF. A value of 0 means either an error
+occured or no hosts were available. It is safe to assume system default
+if this occurs.
+
=back
=head1 RETURN
=head1 NOTES
memcached_behavior_set() in version .17 was changed from taking a pointer
-to data value, to taking a uin64_t.
+to data value, to taking a uin64_t.
=head1 HOME
To find out more information please check:
-L<http://tangent.org/552/libmemcached.html>
+L<https://launchpad.net/libmemcached>
=head1 AUTHOR
projects / awesomized / libmemcached / blobdiff