Memcached is a high performance multithreaded event-based key/value cache store intended to be used in a distributed system.
A fun story explaining usage: https://memcached.org/tutorial
If you're having trouble, try the wiki: https://memcached.org/wiki
If you're trying to troubleshoot odd behavior or timeouts, see: https://memcached.org/timeouts
https://memcached.org/ is a good resource in general. Please use the mailing list to ask questions, github issues aren't seen by everyone!
Be warned that the -k (mlockall) option to memcached might be dangerous when using a large cache. Just make sure the memcached machines don't swap. memcached does non-blocking network I/O, but not disk. (it should never go to disk, or you've lost the whole point of it)
See https://build.memcached.org/ for multi-platform regression testing status.
Feel free to use the issue tracker on github.
If you are reporting a security bug please contact a maintainer privately. We follow responsible disclosure: we handle reports privately, prepare a patch, allow notifications to vendor lists. Then we push a fix release and your bug can be posted publicly with credit in our release notes and commit history.