[infinispan-dev] Interceptor stack for local caches

[Emmanuel Bernard]

BTW, a generic interface based call to interceptors is hard to optimize by the VM AFAIU. 
So having a few specialized implementations of CacheImpl that do hard code the calls to specific interceptor implementations (the 2 methods split ones) would make a lot of sense to me for a handful of selected cases like you are describing Radim. 

> On 22 juin 2015, at 07:42, Emmanuel Bernard <emmanuel at hibernate.org> wrote:
> 
> I am no expect at all of the code base. 
> Wouldn't returning LocalCacheImpl happening in very very specific cases and thus not be of quite limited use?
> 
> And that resonates with the discussion of splitting the interceptor logic into before and after methods. And keeping the state not in the interceptor but in a type less stack passed to these methods. That would  probably reduce the unnecessary allocation you are seeing. This also opened the doors for moving locks outside the execution thread AFAIR. 
> 
> Was this approach ever put on paper even as a few paragraphs somewhere ?
> 
>> On 22 juin 2015, at 07:18, Radim Vansa <rvansa at redhat.com> wrote:
>> 
>> Hi,
>> 
>> few weeks ago I was looking into performance of local cache when 
>> compared to basic concurrent hash map, or data container. I can't find 
>> the exact results now, but the difference was in order of magnitude - 
>> IIRC concurrent hash map was about 20x faster than local cache. There 
>> was no 'bottleneck', but the versatile Infinispan design of commands 
>> traversing through interceptor stack brings some overhead (e.g. 
>> allocation costs with each invocation, not only for writes) while in 
>> some use cases it is not necessary to keep this complexity. The use case 
>> I am looking for is caching in Hibernate ORM, which basically requires 
>> only map with eviction, expiration and transactions in some cases. No 
>> need for cache stores, statistics etc. So far I've found ways to remove 
>> few interceptors [1], but it's few percent, not hundreds of percent 
>> where I would ideally aim.
>> 
>> Therefore, I was considering about an option to inspect cache 
>> configuration and in suitable cases return LocalCacheImpl that would get 
>> rid of the burden: no interceptor stack, no commands instantiation. This 
>> would be transparent to the user. I understand that it will increase 
>> maintenance costs, but it still seems better to me to have it under 
>> wings of Infinispan as caching solution rather than separate project, as 
>> it can share a lot of the codebase.
>> 
>> Do you think that this idea makes sense, or is it just too wild? Do you 
>> think I will crash when trying to implement this?
>> 
>> Radim
>> 
>> [1] https://issues.jboss.org/browse/ISPN-5542
>> 
>> -- 
>> Radim Vansa <rvansa at redhat.com>
>> JBoss Performance Team
>> 
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