memcached_get does not work with UDP. This seems to be a major limitation in UDP support, since the primary use-case for UDP is to reduce get overhead. For example, Facebook uses UDP for gets and TCP for sets:
Clients use UDP and TCP to communicate with memcached servers. We rely on UDP for get requests to reduce latency and overhead. Since UDP is connectionless, each thread in the web server is allowed to directly communicate with memcached servers directly, bypassing mcrouter, without establishing and maintaining a connection thereby reducing the overhead.
As far as I can tell, this behavior is not documented.
memcached_getdoes not work with UDP. This seems to be a major limitation in UDP support, since the primary use-case for UDP is to reducegetoverhead. For example, Facebook uses UDP forgets and TCP forsets:As far as I can tell, this behavior is not documented.