今天在做一个Memcache的session测试，但是在测试的过程中，发现Memcache没有一个比较简单的方法可以直接象redis那样keys *列出所有的Session key，并根据key get对应的session内容，于是，我开始查找资料，翻出来的大部分是一些memcache常用命令等，但是对列出key的办法，讲解却不多，于是来到google，找到了一个国外的资料

具体的内容我套用我的测试环境中，操作如下

1. cmd上登录memcache

 telnet 10.73.13.155 1720

2. 列出所有keys

STATS items
STAT items:1:number 41430
STAT items:1:age 36512
STAT items:1:evicted 20
STAT items:1:evicted_nonzero 20
STAT items:1:evicted_time 283142
STAT items:1:outofmemory 0
STAT items:1:tailrepairs 0
STAT items:1:reclaimed 10402378
STAT items:1:expired_unfetched 8908245
STAT items:1:evicted_unfetched 13
STAT items:2:number 33213085
STAT items:2:age 59197
STAT items:2:evicted 10697552
STAT items:2:evicted_nonzero 10697552
STAT items:2:evicted_time 59198
STAT items:2:outofmemory 0
STAT items:2:tailrepairs 0
STAT items:2:reclaimed 2560738307
STAT items:2:expired_unfetched 2522844623
STAT items:2:evicted_unfetched 10416496

...

STAT items:14:number 396
STAT items:14:age 82483
STAT items:14:evicted 330
STAT items:14:evicted_nonzero 330
STAT items:14:evicted_time 85169
STAT items:14:outofmemory 0
STAT items:14:tailrepairs 0
STAT items:14:reclaimed 14664
STAT items:14:expired_unfetched 709
STAT items:14:evicted_unfetched 92

...

3. 通过itemid获取key

基本上每一个items id（组）里面的key的前缀是相同的。本例中items id为14，第2个参数为列出的长度，0为全部列出。

stats cachedump 8 0

ITEM user_channel_ids_2294580834 [341 b; 1456726791 s]
ITEM user_channel_ids_5197287759 [341 b; 1456880434 s]
ITEM user_channel_ids_1859179390 [341 b; 1456880434 s]
ITEM user_channel_ids_2665075984 [341 b; 1455895155 s]
ITEM user_channel_ids_2639521071 [341 b; 1456880431 s]
ITEM user_channel_ids_5799779996 [341 b; 1456576610 s]
ITEM user_channel_ids_1800406347 [373 b; 1456808894 s]
ITEM user_channel_ids_5645382562 [341 b; 1456878060 s]
ITEM user_channel_ids_5854482532 [357 b; 1456880427 s]
ITEM user_channel_ids_3192133550 [357 b; 1456810596 s]
ITEM user_channel_ids_3605489290 [341 b; 1456843284 s]
ITEM user_channel_ids_5837431613 [373 b; 1456829459 s]
...

4. 通过get获取key值

上面的stats cachedump命令列出了我的session key，接下来就用get命令查找对应的session值。

 get user_channel_ids_2917301923
VALUE user_channel_ids_2917301923 4 341
a:3:{s:2:"id";a:17:{i:0;s:4:"1760";i:1;s:4:"9999";i:2;s:4:"1552";i:3;s:4:"1199";i:4;s:4:"4188";i:5;s:4:"1988";i:6;s:4:"4564";i:7;s:4:"2088";i:8;s:4:"4388";i:9;s:4:"5988";i:10;s:4:"5088";i:11;s:4:"4288";i:12;s:4:"4688";i:13;s:4:"2488";i:14;s:4:"3288";i:15;s:4:"5288";i:16;s:4:"5188";}s:3:"uid";s:10:"2917301923";s:4:"time";s:10:"1449203990";}
END