dormando edited this page May 18, 2016 · 1 revision

Memcached 1.4.17 Release Notes

Date: 2013-12-20


Download Link:


Another bugfix release along with some minor new features. Most notable is a potential fix for a crash bug that has plagued the last few versions. If you see crashes with memcached, please try this version and let us know if you still see crashes.

The other notable bug is a SASL authentication bypass glitch. If a client makes an invalid request with SASL credentials, it will initially fail. However if you issue a second request with bad SASL credentials, it will authenticate. This has now been fixed.

If you see crashes please try the following:

  • Build memcached 1.4.17 from the tarball.
  • Run the "memcached-debug" binary that is generated at make time under a gdb instance
  • Don't forget to ignore SIGPIPE in gdb: "handle SIGPIPE nostop"
  • Grab a backtrace "thread apply all bt" if it crashes and post it to the mailing list or otherwise hunt me down.
  • Grab "stats", "stats settings", "stats slabs", "stats items" from an instance that has been running for a while but hasn't crashed yet.

... and send as much as you can to the mailing list. If the data is sensitive to you, please contact dormando privately.


  • Fix potential segfault in incr/decr routine.
  • Fix potential unbounded key prints (leading to crashes in logging code)
  • Fix bug which allowed invalid SASL credentials to authenticate.
  • Fix udp mode when listening on ipv6 addresses.
  • Fix for incorrect length of initial value set via binary increment protocol.

New Features

  • Add linux accept4() support. Removes one syscall for each new tcp connection.
  • scripts/memcached-tool gets "settings" and "sizes" commands.
  • Add parameter (-F) to disable flush_all. Useful if you never want to be able to run a full cache flush on production instances.


The following people contributed to this release since 1.4.16.

Note that this is based on who contributed changes, not how they were done. In many cases, a code snippet on the mailing list or a bug report ended up as a commit with your name on it.

Note that this is just a summary of how many changes each person made which doesn't necessarily reflect how significant each change was. For details on what led up into a branch, either grab the git repo and look at the output of git log 1.4.16..1.4.17 or use a web view.

     6  dormando
     1  Adam Szkoda
     1  Alex Leone
     1  Andrey Niakhaichyk
     1  Daniel Pañeda
     1  Jeremy Sowden
     1  Simon Liu
     1  Tomas Kalibera
     1  theblop
     1  伊藤洋也