garbage collector

[Ivan Szanto]

Hi Dormando,


> Unfortunately you just patched the wrong problem. Memcached does not
> need an active garbage collector.
>   
Of course it does. With the garbage collector our problems were gone.

> Are you sure your machine was not swapping? Did you set the memory limit
> too high? How did you verify it was "slow" ? What symptoms were you seeing?
>   
Sure it was not swapping. I will dig up the munin graphs for you to have 
a look.
The symptom was that it was unable to put in any more items, which made 
our website unavailable.
> "evictions" counters only go up when a *valid* item is removed from
> cache ahead of time. Your cache was never quite full enough to
> preemptively expire valid items.
>   
Thanks for the explanation. Where can I see in the stats that it throws 
out expired items?
> Memcached is designed to use up to the limit of memory you specify, then
> it will re-use that memory in a very efficient way,
In my previous mail, I wrote about a part of the code where it reuses 
memory.
After I browsed through the whole code, I did not find any other part.  
Is there another part?
Please let me know.
>  so it will never
> release memory back to the operating system. If you're hitting swap, set
> the maxbytes value to be lower with the "-m" option.
 >
> -Dormando
>   
The problem was not that I expected it to release memory to the 
operating system.
The problem was that it did not accept any more new items, because it 
was full of expired items.

Ivan