“Eventually consistent does not mean a day, minute or even second from now… in most cases, it is milliseconds!”
This session will address Cassandra’s tunable consistency model and cover how developers and companies should adopt a more Optimistic Software Design model.
“Can I trust that Cassandra will replicate my data when writing in CL1?”
A Netflix Experiment
• Created a multi-datacenter C* 1.1.7 Cluster of 48 nodes in each datacenter
• Put load in C* cluster
– 100k total operations per second (50k in each datacenter)
• Wrote 1,000,000 records at CL1 in one datacenter
• Read same 1,000,000 records at CL1 in other datacenter
• All records read successfully
• You can trust it!
Hurdles to Eventual Consistency
• In the engineering world: 1 + 1 = 2… not “eventually 2”
• Middle management is scared
– You’ve convinced them to use C*…
– Now you need to convince them to accept low consistency?
• Engaging product teams to implement a contingency plan
Overcoming the Hurdles
• Prove it through a proof of concept
• Show them an improved user experience
– It’s all about the user!