The differences between ApsaraDB for Memcache and the locally-deployed Memcached are as follows.
Deployment: ApsaraDB for Memcache is easy to use and the cache service is available immediately after the purchase. The operations and configurations of the locally deployed Memcached are more complex.
Performance: For a single connection, the I/O performance of ApsaraDB for Memcache is slightly lower than locally-deployed Memcached. For massive and concurrent connections, the I/O performance of ApsaraDB for Memcache is higher than locally-deployed Memcached. (See test report)
Load balancing: Multiple servers in the background ApsaraDB for Memcache cluster automatically implement load balancing, and no configuration is required by users.
Availability: ApsaraDB for Memcache features a high availability because it uses distributed cluster architecture that can avoid SPOF and provide continuous and stable services. The locally-deployed Memcached is far behind ApsaraDB for Memcache in terms of stability.
Resizing: ApsaraDB for Memcache supports one-click online resizing, which is impossible for locally deployed Memcached.
Security: ApsaraDB for Memcache supports multiple security mechanisms such as user password authentication and IP address whitelist configuration for access control. Locally deployed Memcached requires users to design and deploy their own security mechanisms.