In this GridGain presentation: https://www.youtube.com/watch?v=u8BFLDfOdy8&t=1806s <https://www.youtube.com/watch?v=u8BFLDfOdy8&t=1806s>
Valentin Kulichenko explains the CAP theorem and states that Apache Ignite is designed to favour Strong-Consistency (CP) over High-Availability (AP). However, in my test case, my system appears to be behaving as an AP system. Here is my setup: 4 partitioned nodes in 2 availability-zones [AZa-1, AZa-2] [AZb-3, AZb-4], configured as described in this post: http://apache-ignite-users.70518.x6.nabble.com/RESOLVED-Cluster-High-Availability-tp25740.html <http://apache-ignite-users.70518.x6.nabble.com/RESOLVED-Cluster-High-Availability-tp25740.html> With 7,000 records loaded into a table in the cluster with JDBC Thin client: 1. [OK] I can connect to any node and verify that there are 7,000 records with a SELECT COUNT(*) 2. [OK] If I kill all nodes in AZ-a [AZa-1, AZa-2], and connect to one of the remaining online nodes in AZ-b, I can still verify that there are 7,000 records with a SELECT COUNT(*) 3. [?] I then kill one of the remaining two nodes in AZ-b and connect to the single remaining node. Now a SELECT COUNT(*) returns a value of 3,444 records. This seems to illustrate that the partitioning and backup configuration is working as intended. But if Ignite is strongly-consistent (CP), shouldn't the final query fail rather than return an inaccurate result (AP)? Or am I missing some crucial configuration element(s)? -- Sent from: http://apache-ignite-users.70518.x6.nabble.com/
