Plone 4.3.3 - Relstorage

Background

These are my notes for using Relstorage with Plone 4.3.3. My reason for doing this is I wanted to have a live copy of my plone site on a separate server. I wanted things put into one plone site to show up on the other (and vice-versa). This is hard to do with the default plone setup because 'data.fs' is large and plone needs to be restarted when copied it over.

In my searches for a solution I found RelStorage. Relstorage allows you to store you blob data in a mysql database instead of 'data.fs'. Once that data is in mysql, it is easy to replicate between servers with Multi-Master replication (like mariadb galera).
 

Reference Documents

http://shane.willowrise.com/archives/how-to-install-plone-with-relstorage-and-mysql/
http://docs.silvacms.org/2.3/cluster/relstorage.html
http://plone.org/documentation/faq/plone-backup-move
https://mail.zope.org/pipermail/zodb-dev/2012-April/014630.html
https://pypi.python.org/pypi/RelStorage

Issues I had setting up RelStorage

1.) Based on previous directions I thought I needed to patch ZODB files for RelStorage. I have since found out that starting in ZODB 3.9 a patch is no longer needed.

2.) On my first attempt I kept getting a Temporary Directory error. The error I was getting was "Error Value: 'NoneType' object has no attribute 'temporaryDirectory'". Eventually I found it was because I was not specifying 'blob-dir' in 'zinstance\buildout.cfg' (see below).

Instructions

*note* my plone directory is '/opt/PloneRep-4-3-3/'. Replace this with your plone path in in the instuctions below.

1.) edit 'zinstance/buildout.cfg'. 

--Under [buildout], add the following eggs--

eggs =
    Plone
    Pillow
    RelStorage
    MySQL-python

--Under [instance], add the following--

[instance]
rel-storage =
    type mysql
    host 127.0.0.1
    db plone
    user ploneuser
    passwd supersecretpw
    shared-blob-dir false
    blob-dir /opt/PloneRep-4-3-3/zinstance/var/blobstorage
    blob-cache-size 10mb

-- Add to the end of buildout.cfg to get zodbconvert tool --

[zopepy]
scripts = zopepy zodbconvert
 
[zodbconvert]
recipe = zc.recipe.egg
eggs = ${buildout:eggs}
scripts = zodbconvert

2.) Run the plone buildout

*note* buildout may fail if libmysqlclient-dev or libmariadbclient-dev are not installed

cd /opt/PloneRep-4-3-3/zinstance
sudo -u plone_buildout bin/buildout 

3.) If you just want a blank plone site you are done at this point. Start plone with 'bin/plonectl fg' to verify there are no errors. If you want to convert an existing plone site...continue to the next step.

4.) Create a settings xml file for zodbconvert

*note* my data source is my old plone directory, /opt/Plone-4-3-3/ . This is converting data.fs and FileStorage in the 'bushy' format.

/opt/PloneRep-4-3-3/zinstance/conv.xml 

<filestorage source>
  path /opt/Plone-4-3-3/zinstance/var/filestorage/Data.fs
  blob-dir /opt/Plone-4-3-3/zinstance/var/blobstorage
</filestorage>
 
<relstorage destination>
  shared-blob-dir false
  # ZODB Cache Dir
  blob-dir ./var/blobstorage
  blob-cache-size 10mb
  <mysql>
    host 127.0.0.1
    db plone
    user ploneuser
    passwd supersecretpw
  </mysql>
</relstorage>

 5.) Run zodbconvert

cd /opt/PloneRep-4-3-3/zinstance
bin/zodbconvert --clear /opt/PloneRep-4-3-3/zinstance/conv.xml

6.) If the conversion goes successfully, this is a good time to make a backup of your new plone mysql database (I know I used my backup a few times in getting this all working)

7.) you should now be ready to start plone. start it with 'plonectl fg' to make sure there are no errors.