X-Git-Url: https://git.m6w6.name/?a=blobdiff_plain;f=docs%2Fmemcached_behavior.pod;h=2e0240afbe4c0c88a9463e22267739dc79f3543e;hb=55b5455291498ef63c1c34976552d58708a74732;hp=00d762825d2da1f4757e2000b7843820843ba11a;hpb=921abbe1906e77cc18cbe8859bc5afe9494d780e;p=awesomized%2Flibmemcached diff --git a/docs/memcached_behavior.pod b/docs/memcached_behavior.pod index 00d76282..2e0240af 100644 --- a/docs/memcached_behavior.pod +++ b/docs/memcached_behavior.pod @@ -14,7 +14,7 @@ C Client Library for memcached (libmemcached, -lmemcached) 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); @@ -32,7 +32,7 @@ that behavior is currently enabled in the client. 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 @@ -40,7 +40,7 @@ memcached_behavior_set() will flush and reset all connections. =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 +with a memcached server. Not all I/O operations are supported when this behavior is enababled. The following operations will return C when executed with the MEMCACHED_BEHAVIOR_USE_UDP enabled: memcached_version(), memcached_stat(), memcached_get(), @@ -50,7 +50,7 @@ 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. +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 @@ -82,19 +82,19 @@ environments). =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, 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 dont know or dont 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. +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 @@ -117,7 +117,14 @@ and the hash to MEMCACHED_HASH_MD5. =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 @@ -136,16 +143,16 @@ of memcached_callback_set(3). This will be removed in 0.15. 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 @@ -165,7 +172,7 @@ times connection failure. =item MEMCACHED_BEHAVIOR_IO_MSG_WATERMARK -Set this value to tune the number of messages that may be sent before +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). @@ -175,7 +182,7 @@ but the send will block because the input buffer in the kernel is full). 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 +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 @@ -192,7 +199,7 @@ 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). +from your storage commands (set, add, replace, append, prepend). =item MEMCACHED_BEHAVIOR_NUMBER_OF_REPLICAS @@ -202,6 +209,37 @@ 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 @@ -213,12 +251,12 @@ returns failure or success. =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 +L =head1 AUTHOR