Log Memcached Activity

Question

I'm looking to log all activity going on in my memcached server. All reads and writes.

This is going to be used as a distributed daemon for lots of remote php apps in the cloud and need a way to SSH in and check out the activity going on, on the daemon.

I've googled extensively and can't find a single way to do this.

The Redis equivalent would be logging into the interactive console and typing MONITOR.

Thanks in advance.

Answer 1

You can do this using memcached's telnet stats command as such :

• enable capturing information : stats detail on
• wait a while
• disable capturing : stats detail off
• dump the information : stats detail dump

telnet yourhost 11211 and run the sequence above. Note that this will impact greatly the performance.

Also you could check out phpmemcacheadmin - it's a really nice tool for monitoring memcached pools.

Answer 2

You can start your memcached using the -vv parameter:

-vv           very verbose (also print client commands/reponses)

The output is similar to this:

Dec 12 10:33:12 hostname memcached[18350]: <33 new auto-negotiating client connection
Dec 12 10:33:12 hostname memcached[18350]: 33: Client using the ascii protocol
Dec 12 10:33:12 hostname memcached[18350]: <33 set your.key.1 3 300 525
Dec 12 10:33:12 hostname memcached[18350]: >33 STORED
Dec 12 10:33:12 hostname memcached[18350]: <33 get your.key.2
Dec 12 10:33:12 hostname memcached[18350]: >33 sending key your.key.2
Dec 12 10:33:12 hostname memcached[18350]: >33 END

The output is sent to stdout, so you might want to redirect it to some file.