-
zookeeper
ZooKeeper is a
distributed
, open source
distributed
application coordination service, an open source implementation of
Google
's
Chubby , and an important component of Hadoop and Hbase. It is a software that provides consistent services for distributed applications. The functions provided include: configuration maintenance, domain name service, distributed synchronization, group service, etc.
The goal of ZooKeeper is to encapsulate complex and error-prone key services, and provide users with an easy-to-use interface and a system with high performance and stable functions.
In the ZooKeeper code version, interfaces for distributed exclusive locks, elections, and queues are provided. The code is in zookeeper-3.4.3\src\recipes. There are two versions of distributed locks and queues in
Java
and C, and only the Java version is available for elections. (Overview image source:
[2]
)
1.1. What can
zookeeper do
Make sure there is only one master in the cluster
Monitor whether the nodes in the cluster are alive and allocate resources.
Store the configuration information in zookeeper , and the general information can be read when the cluster is started.
E.g:
Hadoop2.0, uses Zookeeper 's event processing to ensure that there is only one active NameNode for the entire cluster, storing configuration information, etc.
HBase, uses Zookeeper 's event processing to ensure that there is only one HMaster in the entire cluster, detects HRegionServer online and down , stores access control lists, etc.
-
zookeeper
edit
ZooKeeper is a
distributed
, open source
distributed
application coordination service, an open source implementation of
Google
's
Chubby , and an important component of Hadoop and Hbase. It is a software that provides consistent services for distributed applications. The functions provided include: configuration maintenance, domain name service, distributed synchronization, group service, etc.
The goal of ZooKeeper is to encapsulate complex and error-prone key services, and provide users with an easy-to-use interface and a system with high performance and stable functions.
ZooKeeper代码版本中，提供了分布式独享锁、选举、队列的接口，代码在zookeeper-3.4.3\src\recipes。其中分布锁和队列有
Java和C两个版本，选举只有Java版本。（概述图片来源：
[2]
）