动物园管理员的实际需要
Actual need of Zookeepers
我是HBase的新手，还在学习中。我只是想知道我们实际需要多少 Zookeeper？
是每个区域服务器一个还是每个集群一个？
谢谢
zookeeper 是按集群的，而不是按区域服务器的。
How many ZooKeepers should I run? You can run a ZooKeeper ensemble
that comprises 1 node only but in production it is recommended that
you run a ZooKeeper ensemble of 3, 5 or 7 machines; the more members
an ensemble has, the more tolerant the ensemble is of host failures.
Also, run an odd number of machines. In ZooKeeper, an even number of
peers is supported, but it is normally not used because an even sized
ensemble requires, proportionally, more peers to form a quorum than an
odd sized ensemble requires. For example, an ensemble with 4 peers
requires 3 to form a quorum, while an ensemble with 5 also requires 3
to form a quorum. Thus, an ensemble of 5 allows 2 peers to fail, and
thus is more fault tolerant than the ensemble of 4, which allows only
1 down peer.
Give each ZooKeeper server around 1GB of RAM, and if possible, its own
dedicated disk (A dedicated disk is the best thing you can do to
ensure a performant ZooKeeper ensemble). For very heavily loaded
clusters, run ZooKeeper servers on separate machines from
RegionServers (DataNodes and TaskTrackers).
我是HBase的新手，还在学习中。我只是想知道我们实际需要多少 Zookeeper？
是每个区域服务器一个还是每个集群一个？
谢谢
zookeeper 是按集群的，而不是按区域服务器的。
How many ZooKeepers should I run? You can run a ZooKeeper ensemble that comprises 1 node only but in production it is recommended that you run a ZooKeeper ensemble of 3, 5 or 7 machines; the more members an ensemble has, the more tolerant the ensemble is of host failures. Also, run an odd number of machines. In ZooKeeper, an even number of peers is supported, but it is normally not used because an even sized ensemble requires, proportionally, more peers to form a quorum than an odd sized ensemble requires. For example, an ensemble with 4 peers requires 3 to form a quorum, while an ensemble with 5 also requires 3 to form a quorum. Thus, an ensemble of 5 allows 2 peers to fail, and thus is more fault tolerant than the ensemble of 4, which allows only 1 down peer.
Give each ZooKeeper server around 1GB of RAM, and if possible, its own dedicated disk (A dedicated disk is the best thing you can do to ensure a performant ZooKeeper ensemble). For very heavily loaded clusters, run ZooKeeper servers on separate machines from RegionServers (DataNodes and TaskTrackers).