Memcached using more than max memory

i have an installation on memcache which i want to use in my production environment but when i have ran a couple of tests it seems that memcache doesn't free up memory even after it has used up all of it allocated memory, Also i logged in and ran a flush_all command but the objects are still in the cache. Here are outputs from some tests

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memcached-tool

memcache-top v0.6       (default port: 11211, color: on, refresh: 3 seconds)

INSTANCE                USAGE   HIT %   CONN    TIME    EVICT/s READ/s  WRITE/s

127.0.0.1:11211         427.1%  0.0%    18      1.4ms   0.0     244     261.0K

AVERAGE:                427.1%  0.0%    18      1.4ms   0.0     244     261.0K

TOTAL:          4.3MB/  1.0MB           18      1.4ms   0.0     244     261.0K

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memcached-tool 127.0.0.1:11211 display


  No  Item_Size  Max_age   Pages   Count   Full?  Evicted Evict_Time OOM

  1     560B         4s       1    1872     yes        0        0 15488

  2     704B        32s       1     559      no        0        0    0

  3     880B         4s       1    1191     yes        0        0 1335

  4     1.1K         9s       1     116      no        0        0    0

  5     1.4K        21s       1      14      no        0        0    0

  6     1.7K         4s       1      17      no        0        0    0

  7     2.1K        84s       1      24      no        0        0    0

  8     2.7K       130s       1      60      no        0        0    0

  9     3.3K        25s       1     290      no        0        0    0

 10     4.2K         9s       1     194      no        0        0    0

 11     5.2K         9s       1     116      no        0        0    0

 15    12.7K       816s       1       1      no        0        0    0

 16    15.9K       769s       1       5      no        0        0    0

 18    24.8K       786s       1       1      no        0        0    0

 21    48.5K       816s       1       1      no        0        0    0

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memcached-tool 127.0.0.1:11211 stats

 127.0.0.1:11211   Field       Value

     accepting_conns           1

           auth_cmds           0

         auth_errors           0

               bytes     4478060

          bytes_read    23964596

       bytes_written   546642860

          cas_badval           0

            cas_hits           0

          cas_misses           0

           cmd_flush           0

             cmd_get      240894

             cmd_set        4504

         conn_yields           0



  connection_structures          21

    curr_connections          18

          curr_items        4461

           decr_hits           0

         decr_misses           0

         delete_hits           0

       delete_misses           0

           evictions           0

            get_hits       43756

          get_misses      197138

           incr_hits           0

         incr_misses           0

      limit_maxbytes     1048576

 listen_disabled_num           0

            开发者_开发知识库     pid        8731

        pointer_size          64

           reclaimed           0

       rusage_system    5.047232

         rusage_user    4.311344

             threads           4

                time  1306247929

   total_connections        3092

         total_items        4504


              uptime        1240

             version       1.4.5

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-m tells memcached how much RAM to use for item storage (in megabytes). Note carefully that this isn't a global memory limit, so memcached will use a few % more memory than you tell it to. Set this to safe values. Setting it to less than 48 megabytes does not work properly in 1.4.x and earlier. It will still use the memory.

Source: https://github.com/memcached/memcached/wiki/ConfiguringServer#commandline-arguments