Grouper Developers Forum

[Chris Hyzer <>]

Are you saying that if a cache config in the xml files doesn't exist that 
things should still work and it should just use the default cache config?  So 
that if people keep things as they are now, then everything will be the same. 
 But if they wipe out their xml files and just have a default config, that 
all caches will use those default config settings?

Thanks,
Chris

-----Original Message-----
From: 

 
[mailto:]
 On Behalf Of Tom Zeller
Sent: Friday, March 25, 2011 1:15 AM
To: Grouper Dev
Subject: [grouper-dev] caching & ldappcng

Caching impacts ldappcng significantly. I had not investigated this before.

Our ehcache config files, ehcache.xml and grouper.ehcache.xml, are
daunting - so many caches to tune !

I wanted to cache "everything", so I decided ehcache.xml and
grouper.ehcache.xml should look like this :

<ehcache>
  <defaultCache
    maxElementsInMemory="500000"
    eternal="false"
    timeToIdleSeconds="120"
    timeToLiveSeconds="120"
    overflowToDisk="false"
  />
</ehcache>

Unfortunately, we sometimes hardcode ehcache parameters - which are
not overriden by the <defaultCache /> element.

So, adding a method to EhcacheController which uses <defaultCache/>
unless a configuration is specified :

  public Cache getCacheWithDefaults(String name) {
    this.initialize();
    if (!this.mgr.cacheExists(name) ) {
      mgr.addCache(name);
    }
    return mgr.getCache(name);
  }

and calling this method in the constructor of CachingAccessResolver,
CachingAttrDefResolver, and CachingNamingResolver

  public CachingAccessResolver(AccessResolver resolver) {
    super(resolver);
    this.cc = new EhcacheController();

    // init cache
    cc.getCacheWithDefaults(CACHE_HASPRIV);
  }

means that it would be possible to configure all caches using <defaultCache/>.

I also wrote a helper method to display ehcache statistics :

2011-03-25 00:07:23,408: [Timer-3] INFO
edu.internet2.middleware.ldappc.spml.PSPCLI.run(157) -  - End of
ldappc-ng execution : 36 ms
2011-03-25 00:07:23,411: [Timer-3] INFO
edu.internet2.middleware.ldappc.spml.PSPCLI.run(166) -  -
cache hit ratio  75%      3 hits      1 miss :
edu.internet2.middleware.grouper.FieldFinder.fieldCache
cache hit ratio  56%      5 hits      4 miss :
edu.internet2.middleware.grouper.GroupTypeFinder.typeCache
cache hit ratio  50%     10 hits     10 miss :
edu.internet2.middleware.grouper.subj.CachingResolver.FindByIdentifier
cache hit ratio  50%     10 hits     10 miss : SpmlDataConnector
cache hit ratio   0%      0 hits     15 miss :
edu.internet2.middleware.grouper.Field
cache hit ratio  67%      2 hits      1 miss :
edu.internet2.middleware.grouper.Group
cache hit ratio  75%     39 hits     13 miss :
edu.internet2.middleware.grouper.Member
cache hit ratio  67%      2 hits      1 miss :
edu.internet2.middleware.grouper.Stem

If you read this far ...

Armed with such statistics and the ease of configuring one
<defaultCache />, I think deployers of ldappcng would have an easier
time tuning caching to meet their needs.

I have not committed anything yet, let me know what you think.

TomZ