collective.buildout.cluster 0.1

Detailed Documentation

Example usage

We’ll start by creating a buildout that contains a base ZEO Client, a ‘cluster’ ZEO Client and two ZEO Servers:

>>> write('buildout.cfg',
... r"""
... [buildout]
... parts =
...    instance-1
...    instance-2
...    server-1
...    server-2
...
... [instance-1]
... http-address = 8080
... recipe = plone.recipe.zope2instance
... zeo-address = 8100
... zeo-client = on
...
... [instance-2]
... recipe = collective.recipe.zope2cluster
... http-address = 8081
... instance-clone = instance-1
...
... [server-1]
... recipe = plone.recipe.zope2zeoserver
... zeo-address = 8100
...
... [server-2]
... recipe = plone.recipe.zope2zeoserver
... zeo-address = 8101
... """)

>>> write('.installed.cfg',
... r"""
... [instance-1]
... bin-directory = C:\src\server-buildout\5.0\bin
... http-address = 8080
... location = C:\src\server-buildout\5.0\parts\instance-1
... recipe = plone.recipe.zope2instance
... zeo-address = 8100
... zeo-client = on
... zope2-location = C:\src\server-buildout\5.0\parts\zope2
...
... [instance-2]
... http-address = 8081
... location = C:\src\server-buildout\5.0\parts\instance-2
... recipe = collective.recipe.zope2cluster
... instance-clone = instance-1
... zope2-location = C:\src\server-buildout\5.0\parts\zope2
...
... [server-1]
... location = C:\src\server-buildout\5.0\parts\server-1
... bin-directory = C:\src\server-buildout\5.0\bin
... recipe = plone.recipe.zope2zeoserver
... zeo-address = 8100
... zope2-location = C:\src\server-buildout\5.0\parts\zope2
...
... [server-2]
... location = C:\src\server-buildout\5.0\parts\server-2
... bin-directory = C:\src\server-buildout\5.0\bin
... recipe = plone.recipe.zope2zeoserver
... zeo-address = 8101
... zope2-location = C:\src\server-buildout\5.0\parts\zope2
... """)

Reading the cluster configuration from those files should list two servers and two client instances:

>>> import os
>>> from collective.buildout.cluster.cluster import Cluster

>>> cluster = Cluster(os.getcwd(), 'buildout.cfg', '.installed.cfg')
cwd: ...

>>> for server in cluster.getServers():
...     print server.getInstanceName()
...     print server.getInstanceCtl()
...     print server.getPort('zeo')
...     print
server-1
C:\src\server-buildout\5.0\bin\server-1
8100
<BLANKLINE>
server-2
C:\src\server-buildout\5.0\bin\server-2
8101
<BLANKLINE>

>>> for client in cluster.getClients():
...     print client.getInstanceName()
...     print client.getInstanceCtl()
...     print client.getPort('http')
...     print
instance-1
C:\src\server-buildout\5.0\bin\instance-1
8080
<BLANKLINE>
instance-2
C:\src\server-buildout\5.0\bin\instance-2
8081
<BLANKLINE>

Now, let’s add a third client and make sure the buildout.cfg file was changed accordingly:

>>> settings = {'instance-clone': 'instance-1',
...             'http-address': '8082'}

>>> client = cluster.addNewClient('instance-3', settings=settings)

>>> cat('buildout.cfg')
<BLANKLINE>
...
parts =
   instance-1
   instance-2
   instance-3
   server-1
...
[instance-3]
recipe = collective.recipe.zope2cluster
http-address = 8082
instance-clone = instance-1

>>> client['http-address']
'8082'

>>> client['instance-clone']
'instance-1'

>>> client['name']
'instance-3'

Trying to add another client by the same name should fail:

>>> cluster.addNewClient('instance-3', settings=settings)
Traceback (most recent call last):
...
ValueError: A section named 'instance-3' already exists!

Changing a port number, or even enabling a port should be possible:

>>> i2 = cluster.getClient('instance-2')
>>> i2.setPort('http', '8091')

>>> i2['http-address']
'8091'

>>> i2.setPort('webdav', '8092')

>>> i2['webdav-address']
'8092'

>>> cat('buildout.cfg')
<BLANKLINE>
...
[instance-2]
recipe = collective.recipe.zope2cluster
http-address = 8091
instance-clone = instance-1
webdav-address = 8092
...

So should disabling a port (by setting it to None):

>>> i2.setPort('webdav', None)

>>> cat('buildout.cfg')
<BLANKLINE>
...
[instance-2]
recipe = collective.recipe.zope2cluster
http-address = 8091
instance-clone = instance-1
...

>>> i2['webdav-address']
Traceback (most recent call last):
...
KeyError: 'webdav-address'

Finally, deleting a client should be possible as well:

>>> for client in cluster.getClients():
...     print client.getInstanceName()
instance-1
instance-2
instance-3

>>> cluster.removeClient('instance-3')

>>> cat('buildout.cfg')
<BLANKLINE>
...
parts =
   instance-1
   instance-2
   server-1
...

>>> for client in cluster.getClients():
...     print client.getInstanceName()
instance-1
instance-2

Contributors

Sidnei da Silva, Author

Change history

0.1 (2009-03-04)

• Implemented support for reading cluster configuration from a buildout.cfg [sidnei]

• Implemented support for starting/stopping instances [sidnei]

• Implemented support for creating new instances [sidnei]

• Created recipe with ZopeSkel [sidnei]

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