Have done some more debugging and here is what I have found.
The general main differences for these two servers seems to be:
'curr_items': '132819', (memcached 1.4.5)
'curr_items': '3907837', (memcached 1.2.2)
Total items seem to be very similar, i.e.
'total_items': '62899221', (memcached 1.4.5)
'total_items': '68416527', (memcached 1.2.2)
Testing memcached 1.2.2 and memcached 1.4.5 and filling it up with
sample data it seems like memcached 1.4.5 is much better at using
memory that has been allocated by expired items. Is this correct?
If so, it would mean that our cache is way underutilized in general
and that 1.4.5 is much better at managing memory (i.e. it won't
allocate memory if it does not need to).
Could someone that's familiar with memcached internals please confirm
this.
Regards,
amix
On 22 Okt., 23:12, amix <ami...@gmail.com> wrote:
> We have recently added a new memcached server, but it's underutilized
> or at least not as much utilized as our other memcached servers. The
> difference between this new server and the older server are following:
> * memcached 1.4.5 is run (instead of memcached 1.2.2)
> * Ubuntu 10 is run (instead of Ubuntu 8)
>
> Has something drastically changed between 1.2.2 and 1.4.5? Or has
> something changed between Ubuntu 8 and Ubuntu 10? Anybody else having
> a similar issue?
>
> Here is usage patterns from these two servers. Each of them have 3GB
> available, but the server running 1.4.5 only uses around 300MB. We are
> unsure what the cause is. These servers are run like this:
>
> memcached -m 3072 -k -p 11221 -u plurk -l 192.168.0.35 -c 10240
>
> Regards,
> amix
>
> [ ( '192.168.0.35:11221 (1)',
> { 'accepting_conns': '1',
> 'auth_cmds': '0',
> 'auth_errors': '0',
> 'bytes': '71301667',
> 'bytes_read': '68596588527',
> 'bytes_written': '215641263049',
> 'cas_badval': '0',
> 'cas_hits': '0',
> 'cas_misses': '0',
> 'cmd_flush': '0',
> 'cmd_get': '246655883',
> 'cmd_set': '62909113',
> 'conn_yields': '0',
> 'connection_structures': '2526',
> 'curr_connections': '2262',
> 'curr_items': '132819',
> 'decr_hits': '0',
> 'decr_misses': '0',
> 'delete_hits': '2297822',
> 'delete_misses': '23286159',
> 'evictions': '0',
> 'get_hits': '163185291',
> 'get_misses': '83470592',
> 'incr_hits': '25466',
> 'incr_misses': '0',
> 'limit_maxbytes': '3221225472',
> 'listen_disabled_num': '0',
> 'pid': '7319',
> 'pointer_size': '64',
> 'reclaimed': '36224211',
> 'rusage_system': '8341.840000',
> 'rusage_user': '3173.390000',
> 'threads': '4',
> 'time': '1287781046',
> 'total_connections': '139794',
> 'total_items': '62899221',
> 'uptime': '514507',
> 'version': '1.4.5'}),
> ( '192.168.0.70:11221 (1)',
> { 'bytes': '2879886510',
> 'bytes_read': '65548028841',
> 'bytes_written': '179395226207',
> 'cmd_get': '277646387',
> 'cmd_set': '68425776',
> 'connection_structures': '2553',
> 'curr_connections': '2291',
> 'curr_items': '3907837',
> 'evictions': '0',
> 'get_hits': '193391910',
> 'get_misses': '84254477',
> 'limit_maxbytes': '3221225472',
> 'pid': '17580',
> 'pointer_size': '64',
> 'rusage_system': '6113.240000',
> 'rusage_user': '3507.560000',
> 'threads': '1',
> 'time': '1287781045',
> 'total_connections': '138271',
> 'total_items': '68416527',
> 'uptime': '514517',
> 'version': '1.2.2'})]