[infinispan-dev] Infinispan 4.1 | Eviction policies for Memcached protocol

[Paul Ferraro]

Owen?  Columbia Comp Eng '98?  What are you up to these days?

On Thu, 2010-09-23 at 02:23 -0500, Owen Tran wrote:
> Hi,
> 
>  
> 
> I’m actively trying to replace memcached with Infinispan with the
> memcached server. Swapping it in with my existing whalin client was
> very simple, I just had to disable the binary protocol. The problem
> I’m facing is that evictions based on maxEntries aren’t working.
> Here’s the configuration I’m using (btw, I’ve tried playing with all
> the parameters by trying different strategies, using DEFAULT
> threadPolicy, change wakeUpInterval, and maxEntries by powers of 2.
> 
>  
> 
> <infinispan>
> 
>         <global>
> 
>                 <globalJmxStatistics enabled="true"/>
> 
>         </global>
> 
>         <default>
> 
>                 <jmxStatistics enabled="true"/>
> 
>                 <eviction wakeUpInterval="500" maxEntries="1024"
> strategy="LIRS" threadPolicy="PIGGYBACK"/>
> 
>                 <expiration maxIdle="3600000" lifespan="-1"/>
> 
>         </default>
> 
> </infinispan>
> 
>  
> 
>  
> 
> Infinispan will remove entries that are expired, but it doesn’t seem
> to evict any items when the cache exceeds the number of maxEntries.
> I’ve enabled trace and using JMX to peer into the number of entries,
> and I easily exceed the maxEntries by running a junit test loading it
> with 10,000 entries. 
> 
>  
> 
> I noticed in the DefaultDataContainer it only handles immortalEntries
> with the bounded concurrency map. Is the memcached server somehow only
> setting items as mortal entries? If so, this means that the behavior
> for this memcached is really deficient, since you’re bound by memory
> and can’t LRU once maxEntries is reached. The only saving grace are
> the expiration settings. Is there a suggestion on how I can fix this
> so I can have the behavior of LRU with eviction? 
> 
>  
> 
> Thanks, 
> 
> Owen
> 
>  
> 
>  
> 
> Code from DefaultDataContainer…
> 
>  
> 
> protected DefaultDataContainer(int concurrencyLevel, int maxEntries,
> EvictionStrategy strategy, EvictionThreadPolicy policy) {
> 
>  
> 
>       // translate eviction policy and strategy
> 
>       switch (policy) {
> 
>          case PIGGYBACK:
> 
>          case DEFAULT:
> 
>             evictionListener = new DefaultEvictionListener();
> 
>             break;
> 
>          default:
> 
>             throw new IllegalArgumentException("No such eviction
> thread policy " + strategy);
> 
>       }
> 
>  
> 
>       Eviction eviction;
> 
>       switch (strategy) {
> 
>          case FIFO:
> 
>          case UNORDERED:
> 
>          case LRU:
> 
>             eviction = Eviction.LRU;
> 
>             break;
> 
>          case LIRS:
> 
>             eviction = Eviction.LIRS;
> 
>             break;
> 
>          default:
> 
>             throw new IllegalArgumentException("No such eviction
> strategy " + strategy);
> 
>       }
> 
>       immortalEntries = new BoundedConcurrentHashMap<Object,
> InternalCacheEntry>(maxEntries, concurrencyLevel, eviction,
> evictionListener);
> 
>       mortalEntries = new ConcurrentHashMap<Object,
> InternalCacheEntry>(64, 0.75f, concurrencyLevel);
> 
>       entryFactory = new InternalEntryFactory();
> 
>    }
> 
>  
> 
> _______________________________________________________  
> Owen Tran || VP, Engineering || ezRez Software, Inc. 
> 
> 
> 
>  
> 
> 
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