memcached counters missing in action

Charlie Spurr cspurr at kayak.com
Fri Mar 24 21:30:56 UTC 2006


Ah, yes, then I've misunderstood what the expiration setting
controls. Thanks for clarifying. So, setting an expiration on
a counter is not useful to me then.

One last question, if I'm decrementing a counter down to zero
by amounts greater than 1, I need to distinguish between the
"object not found" case and a valid -1 result (e.g. decr
a counter by 50 whose current value is 49). Is there a way
to make this distinction or should I just scale up my counters
to avoid approaching zero?

Thanks,
Charlie Spurr

On Mar 24, 2006, at 3:46 PM, Greg Whalin wrote:

> No, the incr/decr calls will return -1 when the object is not found in
> cache.  I am somewhat confused by your line of questioning.  Are you
> assuming that setting an expiration will ensure that the object  
> lives in
> cache for that duration?  That is not what an expiration does.   
> Setting
> an expiration ensures that the object will NOT live in cache past the
> expire.  It makes no promises that the object will be there until the
> expiration.
>
> gw
>
> Charlie Spurr wrote:
>> Bummer...
>>
>> So, if I understand what's been said so far, I have to call
>> getCounter prior to every decr call to see if the counter is
>> still in the cache. If it's not in the cache reload it using
>> storeCounter and then I can call the decr method.
>>
>> Is that right?
>>
>> _Charlie
>>
>>
>> On Mar 24, 2006, at 3:23 PM, Greg Whalin wrote:
>>
>>> Nope, that won't work.  That will store a serialized Long(1000)  
>>> object
>>> to the cache.  Calling incr() or decr() on it will reset it to 0
>>> (according to the api docs).
>>>
>>> Charlie Spurr wrote:
>>>> Greg,
>>>> Yes, I would like to set an expiration time on counters so
>>>> please add that to the queue for improvements for the Java
>>>> client.
>>>>
>>>> In the meantime, would this work...
>>>> Long balance = new Long(10000);
>>>> MemCachedClient = MemCachedClient();
>>>> client.set("Balance1", balance, expireDate);
>>>> client.decr("Balance1", 50);
>>>> client.getCounter("Balance1");
>>>>
>>>> or would I have to use (Long)client.get("Balance1");
>>>> instead of getCounter?
>>>>
>>>> _Charlie
>>
>



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