>The backups which is mentioned in the documentation, how do I define which node is the primary node and >which node is the backup node.
It defined by Affinity Function, you can read about it here: https://apacheignite.readme.io/docs/affinity-collocation#section-affinity-function >I will have a four node cluster in two data centers , is it normal to think each data center would have one >primary node and one backup node. What would happen in the scenario that the primary node on one dc >cannot reach the primary node on the other dc? I think that you not fully understand how partitioned caches work. Node can be primary for the part of the partitions, while other nodes will have other parts as primary. Here is basic information about Partitioned cache that should be enough to start: https://apacheignite.readme.io/docs/cache-modes#section-partitioned-mode >I assume that org.apache.ignite.spi.discovery.tcp.TcpDiscoverySpi is to be used for the dsicoverySpi property >even for Partitioned Caches. Are there special properties that should be filled in for the partitioned cache >except for addresses and ports? discoverySpi doesn't affect caches at all, so, you don't need to change anything at org.apache.ignite.spi.discovery.tcp.TcpDiscoverySpi configuration >Most of the caches I am using is using uuid as keys , in that case how would affinity collocation of the keys >work? Unfortunately I cannot change the key structure in a short notice. Do you want to collocate Data with Data or Compute with Data? In both cases you can find information on this page: https://apacheignite.readme.io/docs/affinity-collocation Evgenii -- Sent from: http://apache-ignite-users.70518.x6.nabble.com/
