$md->setOption(Memcached::OPT_HASH, Memcached::HASH_CRC);
第二种一致性哈希算法：
memcache在php.ini中加
Memcache.hash_strategy =consistent
Memcache.hash_function =crc32
memcached在程序中加(未确认)
$md->setOption(Memcached::OPT_DISTRIBUTION, Memcached::DISTRIBUTION_CONSISTENT);
$md->setOption(Memcached::OPT_HASH, Memcached::HASH_CRC);
或
$mem->setOption(Memcached::OPT_DISTRIBUTION,Memcached::DISTRIBUTION_CONSISTENT);
$mem->setOption(Memcached::OPT_LIBKETAMA_COMPATIBLE,true);
一些参考文档:
memcached分布测试报告（一致性哈希情况下的散列函数选择）：
http://www.iteye.com/topic/346682
php模块memcache和memcached区别： //www.jb51.net/article/27366.htm
PHP模块：Memcached > Memcache：//www.jb51.net/article/27367.htm
20110509@@UPDATE：
如果安装libmemcached有如下出错提示：
make[2]: *** [clients/ms_conn.o] Error 1
make[2]: Leaving directory `/www/soft/libmemcached-0.48'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/www/soft/libmemcached-0.48'
make: *** [all] Error 2
可在configure时增加--disable-64bit CFLAGS="-O3 -march=i686"
即：./configure --prefix=/usr/local/libmemcached --with-memcached --disable-64bit CFLAGS="-O3 -march=i686"
