The below shows node group configuration for:
2 Comupter
2 Replicas
Each computer running 2 data nodes
Node configuration: 2 node groups
Node Group 1
db1
part 1
part 3
db2
part 3
part 1
Node Group 2
db3
part 2
part 4
db4
part 4
part 2
db1 and db3 make one replica, and db2 and db4 make up the other.
You could loose db2 and db3 or db4 and still be up and running.
You could loose db1 and db3 or db4 and still be up and running.
You could loose db3 and db1 or db2 and still be up and running.
You could loose db4 and db1 or db2 and still be up and running.
db1 services part 1 and maintains a copy of part 3 incase it needs to take over that part as well.
db2 services part 3 and maintains a copy of part 1 incase it needs to take over that part as well.
db3 services part 2 and maintains a copy of part 4 incase it needs to take over that part as well.
db4 services part 4 and maintains a copy of part 2 incase it needs to take over that part as well.
I hope this helps.
Jonathan Miller
Austin, Texas USA
Senior QA Developer
MySQL AB www.mysql.com
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