• Laravel Version: 8.x
• PHP Version: 7.x
• Database Driver & Version: php-memcached (https://github.com/php-memcached-dev/php-memcached) Version: v3.x

Description:

Current memcached driver always call setOptions-method when creating memcached-object. We should avoid calling setOptions when we already have a connection. https://github.com/laravel/framework/blob/8.x/src/Illuminate/Cache/MemcachedConnector.php#L18-L59

Some options quit connections by calling send_quit-function of libmemcached library every time, so persistent-connection does not work. https://github.com/awesomized/libmemcached/blob/193e5b33334e6209b87d23740a93db8eeef942b1/src/libmemcached/behavior.cc#L48-L282

The options are as follows.

Memcached::OPT_BINARY_PROTOCOL
Memcached::OPT_NO_BLOCK
Memcached::OPT_USE_UDP
Memcached::OPT_TCP_NODELAY
Memcached::OPT_TCP_KEEPALIVE
Memcached::OPT_SOCKET_SEND_SIZE
Memcached::OPT_SOCKET_RECV_SIZE