[Rt-devel] _ACLCache Clearing

[Ruslan U. Zakirov]

Matthew Watson wrote:
> Hi,
> 
> 
> Using rt 3.2.2/mod_perl
> 
>  
> 
>  
> 
>  Continuing on with my struggles to get RT3 running well enough to 
> migrate to, currently looking into the caching done on the ACL system, 
> specifically _/ACL_KEY/_CACHE in Principal_Overlay.pm ,
> 
>  
> 
> Doing my testing on index.html , I’m confused about 2 things,
> 
>  
> 
> Firstly, the cache doesn’t really seem to kick in until the 3^rd page load.
> 
> Eg,
> 
> 1^st page load, all unseen ACL requests must be fetched from the 
> database, any duplicate ACL requests within this page load gets a cache hit,
> 
> 2^nd  page load, same as first (same number of queries having to be fall 
> through to the database)
> 
> 3^rd page load, massive increase in the number of requests getting cache 
> hits.
> 
>  
> 
> Now, the bit I don’t get it, why the 2^nd page load doesn’t get the 
> increase in cache hits?
Do you test in apache -X mode? If no then it's normal results. This 
cache is not shared between processes.

> 
>  
> 
> The second thing I can’t work out, if I wait more than about 30 seconds 
> to reload the page, the cache seems to be empty, and we have to go back 
> to querying the database for the ACL info. Now, it would stand to reason 
> that I could increase the $cache_timeout value in 
> Principal_Overlay::HasRight , but that doesn’t seem to effect it at all. 
>  I guess the cache is getting cleared out somewhere else, but I can’t 
> find where.
I don't remeber where TTL of the record is controlled, but this cache is 
not size limited so you if you increase TTL then increase memory usage.

> 
>  
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> Any hints on either of these would be fantastic J
>