View stunning SlideShares in full-screen with the new iOS app!Introducing SlideShare for AndroidExplore all your favorite topics in the SlideShare appGet the SlideShare app to Save for Later — even offline
View stunning SlideShares in full-screen with the new Android app!View stunning SlideShares in full-screen with the new iOS app!
cap theorem• Eric Brewer (ex-Inktomi)• Proved by Lynch and Gilbert
cap theoremIt is impossible in the asynchrounous network model to implement a read/write object that garantuees the following properties: - Availability - Atomic consistency in fair transactions Or: If the network is broken, your database won’t work
AP vs CP• Real choices are • Available - Partition • Consistent - Partion
AP• Multiple Nodes participate in writes• System will be Eventually Consistent • Storage System guarantees if there are no new updates, all reads will eventually return the same, last updated valueExamples:- DNS- ASync replication- MongoDB with Slave-OK- Memcache