[Opensim-users] What is the best way to manage asset cache on an OSgrid set of regions

[tringate at gmail.com]

I run my regions on three servers.  After ubit's explanation of how the 
cache works I have set up a common cache on each server and run a cron 
process nightly to remove any file that has not been accessed in the past 26 
hours.

Remember the file "date modified" is updated whenever that file is accessed 
in the cache.

This keeps the number of files to a reasonable number in the cache, and 
allows for frequently accessed files to remain in cache indefinitely.

Deleting the entire cache on a periodic bases does not sound like a good 
idea to me in terms of load on the asset server.  If you have a file that is 
constantly being accessed within a 24 hour period it will be server from 
cache but if it is less frequently accessed then the asset server would be 
the source.  I have been thinking about changing the trim time to be 48 
hours to see if the number of files changes appreciably.

I restart all of my regions every night so items on the region should always 
remain in cache.  That is why I set the trim function to remove on a basis 
of 26 hours.

Tom

-----Original Message----- 
From: David Saunders
Sent: Thursday, February 1, 2018 12:57 PM
To: opensim-users at opensimulator.org
Subject: Re: [Opensim-users] What is the best way to manage asset cache on 
an OSgrid set of regions

Hey,

This what I have found out.

The cache will grow.
You can delete it at any time, it will be rebuilt. So each of our servers
deletes the cache files from time to time.
cache file reduced the load on the asset server, this is very important
When the asset server is in a different location on the internet.
Cache is good when you allot of shared assets between simulators., it
allows local files to be used when you get cache hits.

We run 20 of single region simulators on several servers It does help with
the load on the asset server and the database chop.
We do use the floatsome cache, thought about a RAM cache a few times but I
studied it some and thing the size of some or regions would make it
unpractical to implement.

David


On Sat, Jan 6, 2018 at 3:29 PM, AJLDuarte <ajlduarte at sapo.pt> wrote:

> Hi,
>         A) yes it is good idea to share assets cache
>         B and C)
>         Cache will grow for ever taking 2 much disk space possible with
> useless entries.
>         Using one instance to do expires is a option, it will even try to
> not delete assets in use, but just on that instance, so not that useful in
> this case, just waste of cpu.
>         Using a external tool (both windows cmd and bash have usable
> commands) to delete files modified long ago is another option.
>         Wrong deletes should not be a major issue, assuming all assets are
> on grid databases, if not you are in trouble anyways :)
> Regards,
> Ubit
>
> -----Original Message-----
> From: opensim-users-bounces at opensimulator.org [mailto:
> opensim-users-bounces at opensimulator.org] On Behalf Of tringate at gmail.com
> Sent: Saturday, January 06, 2018 04:08
> To: OS-Opensim Users
> Subject: [Opensim-users] What is the best way to manage asset cache on an
> OSgrid set of regions
>
> I run three servers each have a few instances of opensim running on them
> and all of the regions are on OSgrid.
>
> I have a common asset cache  for each servers, that all the instances
> use.  Maybe that is not a good idea, but I thought it might help keep it’s
> size smaller than every instance having it’s own asset cache.
>
> Up to now I have not expired any items in the cache.  Yes, they are
> massive in size.
>
> I have been thinking about having one instance expire the cache and using
> a retention time of 48 hours.
>
> Is that a good or bad idea?
>
> I do have a fair amount of activity on each server as I run free home
> sites for many OSgrid users.
>
> I am wondering a few things:
>
> - Is running a single cache for several instances of opensim a good or bad
> idea?
> - Is not expiring the cache a good or bad idea?
> - Can one instance do the expiring of the cache for all instances since
> they all share the same cache?
>
> Tom
>
>
>
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