[Zodb-checkins] CVS: Packages/ZEO - ZopeREADME.txt:1.1
Jim Fulton
jim@digicool.com
Tue, 27 Mar 2001 18:46:41 -0500 (EST)
Update of /cvs-repository/Packages/ZEO/doc
In directory korak:/tmp/cvs-serv14385
Added Files:
ZopeREADME.txt
Log Message:
*** empty log message ***
--- Added File ZopeREADME.txt in package Packages/ZEO ---
Zope Enterprize Objects
Put this package (the ZEO directory, without any wrapping directory
included in a distribution) in your Zope lib/python.
Starting (and configuring) the ZEO Server
To start the storage server, go to your Zope install directory and::
python lib/python/ZEO/start.py -p port_number
(Run start without arguments to see options.)
Of course, the server and the client don't have to be on the same
machine.
If the server and client *are* on the same machine, then you can use
a Unix domain socket::
python lib/python/ZEO/start.py -U filename
The start script provides a number of options not documented here.
See doc/start.txt for more information.
Running Zope as a ZEO client
To get Zope to use the server, create a custom_zodb module,
custom_zodb.py, in your Zope install directory, so that Zope uses a
ClientStorage::
import ZEO.ClientStorage
Storage=ZEO.ClientStorage.ClientStorage(('',port_number))
(See the misc/custom_zodb.py for an example.)
You can specify a host name (rather than '') if you want. The port
number is, of course, the port number used to start the storage
server.
You can also give the name of a Unix domain socket file::
import ZEO.ClientStorage
Storage=ZEO.ClientStorage.ClientStorage(filename)
There are a number of configuration options available for the
ClientStorage. See doc/ClientStorage.txt for details.
If you want a persistent client cache which retains cache contents
across ClientStorage restarts, you need to define the environment
variable, ZEO_CLIENT, to a unique name for the client. This is
needed so that unique cache name files can be computed. Otherwise,
the client cache is stored in temporary files which are removed when
the ClientStorage shuts down. For example, to start two Zope
processes with unique caches, use something like:
python z2.py -P8700 ZEO_CLIENT=8700
python z2.py -P8800 ZEO_CLIENT=8800
Zope product installation
Normally, Zope updates the Zope database during startup to reflect
product changes or new products found. It makes no sense for
multiple ZEO clients to do the same installation. Further, if
different clients have different software installed, the correct
state of the database is ambiguous.
Starting in Zope 2.2, Zope will not modify the Zope database
during product installation if the environment variable ZEO_CLIENT
is set.
Normally, Zope ZEO clients should be run with ZEO_CLIENT set so
that product initialization is not performed.
If you do install new Zope products, then you need to take a
special step to cause the new products to be properly registered
in the database. The easiest way to do this is to start Zope
once without ZEO_CLIENT set.
The interaction between ZEO and Zope product installation is
unfortunate. In the future, this interaction will be removed by