[Contrib: Evaluation System] Is anybody running evaluations on a cluster?

[Matthew Jones]

Because it was storing the config settings in a ConcurrentHashMap rather
than the BasicMemoryService Cache:

(EvalSettingsImpl->
   private ConcurrentHashMap<String, EvalConfig> configCache = new
ConcurrentHashMap<String, EvalConfig>();)

I'd wouldn't think that they'd ever expire.

I'm also surprised that resetting the Cache in the memory tool does anything
for you, as this only clears out EhCache. (Would probably be 'better' to use
this, but there are so few settings that it isn't a big deal, just more
concerns with CHM like putIfAbsent and checking that the value returned
hasn't been changed by another node in the cluster. For these settings that
seems unlikely though)

It does look like the config settings are reset by
the initiateUpdateStateTimer though every hour.
"       * This will start up a timer which will keep the evaluations up to
date, the disadvantage here is that
        * it will run every hour and on every server and therefore could
increase the load substantially,"
. . .
                      // finally we will reset the system config cache
                      settings.resetCache(null);
" - EvalEvaluationSetupServiceImpl.java

Either way, the patch I supplied allows it to reset within 5 seconds when
the ClusterEventTracking is initiated. ;)

-Matthew

On Thu, Feb 18, 2010 at 12:41 PM, Adam Marshall <adam.marshall at oucs.ox.ac.uk
> wrote:

> we've recently moved from 1.2.1 to trunk but I don’t think we've left the
> settings for an hour to see if the changes are auto-propogated
>
> adam
>
> | -----Original Message-----
> | From: azeckoski at gmail.com [mailto:azeckoski at gmail.com] On Behalf Of
> | Aaron Zeckoski
> | Sent: 18 February 2010 17:28
> | To: Adam Marshall
> | Cc: evaluation at collab.sakaiproject.org
> | Subject: Re: [Contrib: Evaluation System] Is anybody running
> | evaluations on a cluster?
> |
> | I haven't read the rest of this thread and I am still sick but there
> | is a settings cache which is maintained on each server. The cache
> | expires every 60 mins and there is a button in the admin view to force
> | it to refresh immediately (this was added the last time this came up).
> | Not sure how long ago, maybe about a year ago. The theory was that
> | settings change rarely and being out of sync by an hour was ok.
> |
> | Someone was going to maybe move this into the Sakai memory service but
> | I am not sure the state of that.
> | -AZ
> |
> |
> | On Mon, Feb 15, 2010 at 3:00 PM, Adam Marshall
> | <adam.marshall at oucs.ox.ac.uk> wrote:
> | > This is driving us nuts.
> | >
> | > The 'administrate' screen is showing different settings depending on
> | which node of the cluster we view them on. This was causing the
> | Evaluations tool to behave differently dependent on what node of the
> | cluster one is logged into. I have had to manually set them to be the
> | same.
> | >
> | > Surely this cant be right? Can it really be that Evaluations wont run
> | in a clustered environment?
> | >
> | > Adam
> | > _______________________________________________
> | > evaluation mailing list
> | > evaluation at collab.sakaiproject.org
> | > http://collab.sakaiproject.org/mailman/listinfo/evaluation
> | >
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> | >
> |
> |
> |
> | --
> | Aaron Zeckoski (azeckoski (at) vt.edu)
> | Senior Research Engineer - CARET - University of Cambridge
> | https://twitter.com/azeckoski - http://www.linkedin.com/in/azeckoski
> | http://aaronz-sakai.blogspot.com/ - http://tinyurl.com/azprofile
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