[Setup] best practices for creating mounting points on Plone 4.2

Alan Runyan runyaga at gmail.com
Mon Aug 20 18:03:39 UTC 2012

On Sun, Aug 19, 2012 at 8:54 AM, Héctor Velarde
<hector.velarde at gmail.com> wrote:
> hi there!
> we need to create many mounting points inside a Plone 4.2 instance to make
> backups and clean up the database more easily; our customer will create many
> content and we want to separate it on a monthly basis.

I would not recommend doing this.  I do not know any large Plone installations
where multiple Mount points are used inside of a Plone instance.

I had a talk with Hector and here is the outcome:

1. If your database size is increasing; you need to know where/how it
is increasing.

The solution to this is installing collective.stats on production
environments and running the analyzer -> CSV file and reviewing which
operations are causing STOREs.  Most importantly looking at how many
objects ARE being stored when a STORE occurs.

2. zlibstorage is very useful and appears to keep database's fairly
compressed (better than 40%) - this works well due to the fact many
attributes are text based; especially HTML.

3. if your using mysql replication be mindful to replicate only the
tables; you do not need to replication the entire database. just the
core tables.

4. iirc mysql will not "reclaim" the database size.  when you do a
gc-based pack (which will take a long time).  There are 3 types of

  1. pre-pack (usually takes 10 minutes)
  2. pack w/o gc (acts on the pre-packed info; takes 3-4 minutes)
  3. pack w/ gc (this usually takes many many hours)

5. you must lock the database when you dump.  that means any read's
will block until dump is complete.

I will email the ploneconf2012 guys; if I can do a talk on all of the
OPS side of running these sorts of configurations - I would be more
than happy.

> we know there's an old product called MountFolder made for Plone 2.0.5, but
> I don't think it's a good idea to try to used it with our brand new version:
> http://plone.org/products/mountfolder/

dont use it.

> http://svn.plone.org/svn/collective/MountFolder/trunk/README.txt

I would update that and say "DO NOT USE THIS UNLESS YOUR A PROVEN ZODB GURU"

> what are you currently doing to solve problems like this one?

there is no "quick & easy" answer to database size.  Like any "NoSQL"
system - this is all based on application usage and configuration.

Alan Runyan

Skype/Twitter:: runyaga
Office:: 713.942.2377 ext 111
http://ploud.com/  Plone site in less than 10 seconds

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