Memcached Telnet Commands Example

In earlier posts, we saw how to install Memcached server on Mac OS and Unix systems. After that we worked on to start Memcached server at boot time as a daemon process in Mac OS. In this tutorial, we will go through some of the basic Memcached telnet commands that we can use to check the health of the Memcached server. These commands are very helpful in debugging purposes and can be used from any operating system with telnet installed. If you are on a UNIX system, then using ps -eaf | grep memcached command will get you the port Memcached server is running on. For example, when I run this command on my UNIX system, I got below output:

$ ps -eaf | grep memcached
503 55442 55296   0   0:00.15 ttys000    0:00.22 memcached -p 11111 -vv
503 58945 56875   0   0:00.01 ttys003    0:00.01 grep memcached
$

So Memcached server is running on TCP port 11111 and in verbose mode (-vv). If you want to run as daemon process then use -d option in the startup command.

Memcached Telnet Commands

To connect to memcached server with telnet and start a session:

$ telnet localhost 11111

To store data in Memcached server with telnet:

set KEY META_DATA EXPIRY_TIME LENGTH_IN_BYTES

To retrieve data from Memcached through telnet:

get KEY

To overwrite the existing key:

replace KEY META_DATA EXPIRY_TIME LENGTH_IN_BYTES

To delete the key:

delete KEY

To get the server statistics:

stats
stats items
stats slabs

To clear the cache data:

flush_all

To quit the telnet session:

quit

Memcached Server Telnet Example

$ telnet localhost 11111
Trying ::1...
Connected to localhost.
Escape character is '^]'.
set Test 0 100 10
JournalDev
STORED
get Test
VALUE Test 0 10
JournalDev
END
replace Test 0 100 4
Temp
STORED
get Test
VALUE Test 0 4
Temp
END
stats items
STAT items:1:number 1
STAT items:1:age 19
STAT items:1:evicted 0
STAT items:1:evicted_time 0
STAT items:1:outofmemory 0
STAT items:1:tailrepairs 0
END
flush_all
OK
get Test
END
version
VERSION 1.2.8
quit
Connection closed by foreign host.
$

In the next post on memcached, I will provide information about using memcached client in Java. Reference: Memcached Github Commands Page