Das Content Management Framework Zope. Tutorial — ZODB 3.10.3 documentation. This tutorial is intended to guide developers with a step-by-step introduction of how to develop an application which stores its data in the ZODB. Introduction¶ To save application data in ZODB, you’ll generally define classes that subclass persistent.Persistent: # account.py import persistent class Account(persistent.Persistent): def __init__(self): self.balance = 0.0 def deposit(self, amount): self.balance += amount def cash(self, amount): assert amount < self.balance self.balance -= amount This code defines a simple class that holds the balance of a bank account and provides two methods to manipulate the balance: deposit and cash.
Subclassing Persistent provides a number of features: Note that we put the class in a named module. Installation¶ Before being able to use ZODB we have to install it. Creating Databases¶ When a program wants to use the ZODB it has to establish a connection, like any other database. ZODB has a pluggable storage framework. Storing objects¶ Containers and search¶ Dev. A ZODB storage for replication using RAID techniques. Latest Version: 1.0b8 The ZEO RAID storage is a storage intended to make ZEO installations more reliable by applying techniques as used in harddisk RAID solutions.
The implementation is intended to make use of as much existing infrastructure as possible and provide a seamless and simple experience on setting up a reliable ZEO server infrastructure. Note: We use typical RAID terms to describe the behaviour of this system. The ZEO RAID storage is a proxy storage that works like a RAID controller by creating a redundant array of ZEO servers. Therefore, up to N-1 out of N ZEO servers can fail without interrupting. It is intended that any storage can be used as a backend storage for a RAID storage, although typically a ClientStorage will be the direct backend.
The RAID storage could (in theory) be used directly from a Zope server. For this, we leverage the normal ZEO server implementation and simply use a RAID storage instead of a FileStorage. Dev. Dev. Gocept.zeoraid in Launchpad. HAProxy - The Reliable, High Performance TCP/HTTP Load Balancer. HA-Cluster with loadbalancing for Zope (and Plone) Ned Productions - Setting up a dedicated low end Plone ZEO cluster 3/3. [Written Summer 2009] This is the third part of my experiences in setting up a low-end server cluster - refer here for the first part on selecting a VPS and configuring it and refer here for the second part on squeezing the Plone Content Management System onto a ridiculously low end VPS.
At the time of writing (Summer 2009), my 256Mb Xen based VPS has been successfully handling my email and providing two Plone based websites for eight months now - indeed, my two guides above have proved most popular with the internet readership. I guess that people find them useful because they contain a lot of information in one place which takes ages to find elsewhere.
However as in all healthy things, needs grow especially as I lay the foundations for my new businesses. In July 2009 the (in?) And besides, and what is very germane especially here, given my current financial situation of unemployment and being (still!) Now Plone is a most interesting case. Root@slave1:~# . root@slave1:~# . root@slave1:~# .