The document describes how to configure and use memcached. It shows how to install memcached, set runtime options like memory size and number of connections, and check the status and settings using the telnet client. It also provides examples of integrating memcached monitoring into Nagios/Icinga using checks for connections and specific keys.
43. % ./memcached -vvv
slab class 1: chunk size 96 perslab 10922
slab class 40: chunk size 1048576 perslab 1
<26 server listening (auto-negotiate)
<27 server listening (auto-negotiate)
<28 send buffer was 124928, now 268435456
<28 server listening (udp)
<28 server listening (udp)
<28 server listening (udp)
<28 server listening (udp)
<29 send buffer was 124928, now 268435456
<29 server listening (udp)
<29 server listening (udp)
<29 server listening (udp)
<29 server listening (udp)
49. % telnet localhost 11211
Trying ::1...
Connected to localhost.
Escape character is '^]'.
stats settings
STAT maxbytes 16777216
STAT maxconns 32768
STAT tcpport 11211
STAT udpport 0
STAT inter NULL
STAT verbosity 0
STAT oldest 0
STAT evictions on
STAT growth_factor 1.25
STAT chunk_size 48
STAT num_threads 4
STAT cas_enabled no
STAT tcp_backlog 4096
STAT binding_protocol auto-negotiate
STAT auth_enabled_sasl no
STAT item_size_max 1048576
END
61. stats STAT decr_misses 0
STAT pid 4825 STAT decr_hits 0
STAT uptime 7842604 STAT cas_misses 0
STAT time 1284432055 STAT cas_hits 0
STAT version 1.4.4 STAT cas_badval 0
STAT pointer_size 32 STAT auth_cmds 0
STAT rusage_user 23623.394698 STAT auth_errors 0
STAT rusage_system 31550.652571 STAT bytes_read 219935315170
STAT curr_connections 1243 STAT bytes_written 788448026716
STAT total_connections 30886226 STAT limit_maxbytes 1073741824
STAT connection_structures 1373 STAT accepting_conns 1
STAT cmd_get 730786415 STAT listen_disabled_num 0
STAT cmd_set 345660130 STAT threads 4
STAT cmd_flush 0 STAT conn_yields 146
STAT get_hits 455135951 STAT bytes 740742845
STAT get_misses 275650464 STAT curr_items 3623646
STAT delete_misses 17887026 STAT total_items 347251509
STAT delete_hits 10283848 STAT evictions 6986784
STAT incr_misses 4281893 END
STAT incr_hits 111734935
62.
63.
64. #!/usr/local/bin/activeperl
use strict;
use warnings;
use Getopt::Long;
use IO::Socket::INET;
GetOptions(
'H=s' => my $HOST,
'p=s' => my $PORT,
'k=s' => my $KEY
);
my $sock = IO::Socket::INET->new(
PeerAddr => $HOST, PeerPort => $PORT
);
if ( !$sock ) {
print "Couldnt connect to $HOST:$PORT: $!n";
exit(3);
}
$sock->syswrite("get $KEYrn");
$sock->sysread( my $result, 16 );
if ( $result =~ m!^VALUE! ) {
exit(0); #OK
}
print "Not found $KEY on $HOST:$PORTn";
exit(2);
79. STAT 1:chunk_size 80 STAT 2:cmd_set 34606948
STAT 1:chunks_per_page 13107 STAT 2:delete_hits 19083
STAT 1:total_pages 1 STAT 2:incr_hits 283422
STAT 1:total_chunks 13107 STAT 2:decr_hits 0
STAT 1:used_chunks 3 STAT 2:cas_hits 0
STAT 1:free_chunks 32 STAT 2:cas_badval 0
STAT 1:free_chunks_end 13072 ..
STAT 1:mem_requested 220 STAT 42:chunk_size 1048576
STAT 1:get_hits 4438 STAT 42:chunks_per_page 1
STAT 1:cmd_set 11998 STAT 42:total_pages 1
STAT 1:delete_hits 0 STAT 42:total_chunks 1
STAT 1:incr_hits 0 STAT 42:used_chunks 1
STAT 1:decr_hits 0 STAT 42:free_chunks 0
STAT 1:cas_hits 0 STAT 42:free_chunks_end 0
STAT 1:cas_badval 0 STAT 42:mem_requested 779480
STAT 2:chunk_size 104 STAT 42:get_hits 81
STAT 2:chunks_per_page 10082 STAT 42:cmd_set 665
STAT 2:total_pages 16 STAT 42:delete_hits 0
STAT 2:total_chunks 161312 STAT 42:incr_hits 0
STAT 2:used_chunks 116168 STAT 42:decr_hits 0
STAT 2:free_chunks 45144 STAT 42:cas_hits 0
STAT 2:free_chunks_end 0 STAT 42:cas_badval 0
STAT 2:mem_requested 11573385 STAT active_slabs 40
STAT 2:get_hits 29690676 STAT total_malloced 1073454184
80. STAT items:1:number 3 STAT items:3:number 1541997
STAT items:1:age 7841268 STAT items:3:age 6285649
STAT items:1:evicted 0 STAT items:3:evicted 2546432
STAT items:1:evicted_nonzero 0 STAT items:3:evicted_nonzero 0
STAT items:1:evicted_time 0 STAT items:3:evicted_time 1557089
STAT items:1:outofmemory 0 STAT items:3:outofmemory 0
STAT items:1:tailrepairs 0 STAT items:3:tailrepairs 0
STAT items:2:number 116210 ...
STAT items:2:age 6150456 STAT items:42:number 1
STAT items:2:evicted 269 STAT items:42:age 7834430
STAT items:2:evicted_nonzero 0 STAT items:42:evicted 0
STAT items:2:evicted_time 1594950 STAT items:42:evicted_nonzero 0
STAT items:2:outofmemory 0 STAT items:42:evicted_time 0
STAT items:2:tailrepairs 0 STAT items:42:outofmemory 0
STAT items:42:tailrepairs 0