4. status
• developed by NorthScale & Zynga
• used in production (farmville)
• released in June 2010
- Apache 2.0 License
• current version is 1.6 beta 2
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5. cluster structure
• all nodes are alike
- one elected as “coordinator”
• each node is master for part of key
space
- handles all reads & writes
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9. replication
• each vbucket has configurable
number of replicas
• protects against node failure
- quick failover
• master sends updates to replicas
asynchronously
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10. elasticity
• can add nodes at any time
• can remove nodes at any time
- replicas are promoted to master
• rebalancing necessary
• no downtime!
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