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Open source softwares - Zookeeper

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Lesson Description


Lession - #1066 Zookeeper Home


ZooKeeper is an open source Apache project that provides a centralized service for providing configuration information, naming, synchronization, and grouping services across large clusters in distributed systems. The goal is to make these systems easier to manage through improvements and more reliable change propagation.



For applications, ZooKeeper provides the infrastructure for synchronization across nodes by maintaining state type information in the ZooKeeper server's memory. The ZooKeeper server keeps a copy of the entire system state and stores this information in a local log file. Multiple ZooKeeper servers support large Hadoop clusters, with one master synchronizing the top servers.

In ZooKeeper, applications can create so-called Znodes, which are files kept in the memory of the ZooKeeper server. A Znode can be updated from any node in the cluster, and any node in the cluster can register to be notified of changes to that Znode.