使用ZooKeeper打造軟體式負載平衡

1. #JCConf
使⽤用ZooKeeper打造軟體式負
載平衡
⿈黃哲諄

3. ⼤大綱
• What’s ZooKeeper
• The use cases
• ZooKeeper Features
• Zab: The ZooKeeper Atomic Broadcast Protocol
• ZooKeeper Data Model
• Load Balancer
• Apache Curator
• Conclusion

4. What’s ZooKeeper
• ZooKeeper is a coordination service for
distributed system which need to make
multiple nodes perform together correctly.
• Coordination Example:
• Group membership
• Synchronization
• Publish/Subscriber
• It is developed by Java.

5. The use cases

6. ZooKeeper Features
• ZooKeeper Features
• Atomic Operation
• Order guarantee
• Async notification
• High available

7. Zab
• The ZooKeeper Atomic Broadcast Protocol
ZK Server ZK Server ZK Server
Leader Follower Follower

8. Zab
The quorum number is (ZooKeeper server)/2 + 1

9. Data Model
znode

10. Data Model
• znode
• Persistent
• The data exist until clients delete.
• Ephemeral
• The data exist until the client’s session is
closed.
• Sequence
• The znode is added an additional sequential
counter behind the name of znode.

11. Software Load Balance
Cluster
Information
Sense Life cycle

12. Tomcat Example
https://github.com/Lawrence-Huang/zoobalancer

13. Software Load Balancer
• It can be adopted on different systems,
including Gateway, Middleware, etc.

14. Apache Curator
• High-Level API for ZooKeeper

15. Apache Curator
• Leader Election
• Distributed Locks
• InterProcessMutex
• InterProcessReadWriteLock
• InterProcessSemaphore
• Barrier
• Shared Counter

16. Conclusion
• If you are a Java programmer and have
some coordination problems, you can
choose ZooKeeper.

17. #JCConf
Thanks for your listening
lawrence4233@gmail.com