Apache zookeeper Zookeeper,数据版本控制
以下是场景:Apache zookeeper Zookeeper,数据版本控制,apache-zookeeper,Apache Zookeeper,以下是场景: Znode created:create/config 12345(例如在 12/12/12) 已对此配置进行更新,设置/配置34567 (例如,2013年12月12日修改) 一个月后,再次修改配置,set/config 567889(例如,在2013年1月1日修改) 问题: “获取”(或维护)版本历史记录的最佳方式是什么 与“/config”关联,即是否有方法获取 节点中存储的数据的整个历史记录 将当前配置值(即567889)恢复为原始值12345的最佳方法是什么?(通过爬网节点
我需要一些帮助来解决这个问题。谢谢你我认为没有一个简单的方法可以做到这一点。以下是我将如何实现这一目标:
1. divide the configurations in two znodes [say, /Config and /Config/data-*]
- /config/data-* are the data nodes which will store the configuration
- /config will store the history of all the configs so far
2. /Config/data-* is sequential node
So, every znode will have a strictly increasing number appended to it.
For example, /config/data-1, /config/data-2, and so on. Your configuration object
will be stored in data nodes.
/config/data-1 -> 12345
/config/data-2 -> 34567
/config/data-3 -> 56789
3. /config will look like this:
["/config/data-1","/config/data-2","/config/data-3"] or just
["1", "2", "3"]
以下是写入算法:
1. create a data node with new config. Which will return the the actual path.
say /config/data-4
2. now try to do conditional update on /config with "/config/data-4" or just "4" appended to
the existing data i.e.
["/config/data-1","/config/data-2","/config/data-3","/config/data-4"] or just
["1", "2", "3","4"]
- if update succeeds, end.
- else, someone else was simultaneously trying to update the config and won the race.
So, either quit or try again starting with step1.
注意:如果更新失败,您将在树中有有效的孤立节点,可以自动定期清理这些节点
阅读内容如下:
1. call sync [if consistency is important]
2. read /config
3. pick the path which is at the last index in the array retrieved from /config
4. read the config from that path
要回滚,请从/config中存储的列表中删除最后一个条目,或将列表的最后一个但第二个条目追加到末尾您可以在znode中添加一个“watch”并以这种方式跟踪历史?