Memcached stats items

[Alexander Zaitsev]

Thanks. Age is in seconds right? The stats look strange that's why I 
asked this. We store many items (the stream) with no expire time, so it 
is interesting to know how long items live in the cache.

Do I understand correct that the item lifetime depends on item size and 
it can not be estimated from the stats at all?

--
Alexander Zaitsev
AMG Lab Sarl



dormando wrote:
> The 'age' is the oldest item. 'number' isn't automatically adjusted as 
> items are expired, they are adjusted as they are evicted.
>
> I'd recommend upgrading to 1.2.5, where 'stats items' gives 
> per-slab-class eviction stats. You can monitor those numbers to see 
> which item size is causing the most evictions (if any), and pull some 
> estimates based on the rate of evictions.
>
> It's hard / not currently possible to get the average/exact statistics 
> there. They're not really all too necessary; if you're causing 
> evictions either you're storing too many items with no expire time, or 
> you're prematurely expiring items and need more memory, or a restart 
> of memcached.
>
> -Dormando
>
> Alexander Zaitsev wrote:
>> Hi all,
>>
>> Could you advise how to read and understand 'stats items'? In 
>> particular, I would like to know how long items live in cache 
>> (average) before they are pushed out.
>> For example:
>>
>> stats items
>> STAT items:4:number 72083
>> STAT items:4:age 58041
>> STAT items:5:number 89114
>> STAT items:5:age 52292
>> STAT items:6:number 16644
>> STAT items:6:age 52224
>> STAT items:7:number 89586
>> STAT items:7:age 55826
>> STAT items:8:number 5294
>> STAT items:8:age 49658
>> STAT items:9:number 16912
>> STAT items:9:age 53308
>> STAT items:10:number 8455
>> STAT items:10:age 52034
>> STAT items:11:number 9457
>> STAT items:11:age 52201
>> STAT items:12:number 9702
>> STAT items:12:age 52394
>> STAT items:13:number 11206
>> STAT items:13:age 50819
>> STAT items:14:number 6201
>> STAT items:14:age 41512
>> STAT items:15:number 3305
>> STAT items:15:age 43864
>> STAT items:16:number 1323
>> STAT items:16:age 43923
>> STAT items:17:number 704
>> STAT items:17:age 57077
>> STAT items:18:number 281
>> STAT items:18:age 51194
>> STAT items:19:number 223
>> STAT items:19:age 133899
>> STAT items:20:number 179
>> STAT items:20:age 360707
>> STAT items:21:number 64
>> STAT items:21:age 505915
>> STAT items:22:number 23
>> STAT items:22:age 519107
>> STAT items:23:number 2
>> STAT items:23:age 5426
>> STAT items:24:number 1
>> STAT items:24:age 283914
>> STAT items:25:number 1
>> STAT items:25:age 818
>> END
>>
>> Thanks in advance!
>>
>
>
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