Converting single process instance to ZEO cluster

Introduction

See ZEO.

See the plone.app.blob product page for good ZEO configuration examples.

Steps

Use link above for a buildout.cfg example.

Changes needed to a single process buildout.cfg:

• Add [zeo] section:

  [zeo]
  recipe = plone.recipe.zope2zeoserver
  zope2-location = ${zope2:location}
  zeo-address = 127.0.0.1:8100
  zeo-var = ${buildout:directory}/var
  blob-storage = ${zeo:zeo-var}/blobstorage
  eggs = plone.app.blob
  

• Convert [instance] to [client1]. Add the following new settings:

  zeo-client = on
  zeo-address =  ${zeo:zeo-address}
  # If blobs are used
  shared-blob = on
  

• Add [client2] ... [clientN] sections:

  [client2]
  recipe = plone.recipe.zope2instance
  http-address = 8081
  zope2-location = ${client1:zope2-location}
  zeo-client = ${client1:zeo-client}
  zeo-address = ${client1:zeo-address}
  blob-storage = ${client1:blob-storage}
  shared-blob = ${client1:shared-blob}
  user = ${client1:user}
  products = ${client1:products}
  eggs = ${client1:eggs}
  zcml = ${client1:zcml}
  

• Reconfigure [buildout] parts to include zeo, client1, client2...

  [buildout]
  parts =
      plone
      zope2
      zeo
      client1
      client2
  # instance     ... instance is no longer required when running ZEO based instance
  

• Change all ${instance:...} references to ${client1:...}. Search and replace ${instance: -> ${client1:

Starting ZEO cluster

You need to start ZEO and clients independently

• bin/zeo start
• bin/client1 start
• bin/client2 start
• etc.

Other resources

• http://blog.twinapex.fi/2008/07/07/zope-zeo-setupconversion-and-zeo-vs-standalone-performance-review/