I have a group of erlang nodes that are replicating their data through Mnesia's "extra_db_nodes"... I need to upgrade hardware and software so I have to detach some nodes as I make my way from node to node.
How does one remove a node and still preserve the data that was inserted?
[update] removing nodes is as important as adding them. Over time as your cluster grows it must also contract. If not then Mnesia is going to be busy trying to send data to nonexistent nodes filling up queues and keeping the network busy.
[final update] after pouring through the erlang/mnesia source code I was able to determine that it is not possible to completely disassociate nodes. While del_table_copy removes the linkage between tables it is incomplete. I would close this question but none of the close descriptions are adequate.
I wish I had found this a long time ago: http://weblambdazero.blogspot.com/2008/08/erlang-tips-and-tricks-mnesia.html
basically, with a properly functioning cluster....
login to the cluster to be removed
stop mnesia
mnesia:stop().
login to a different node on the cluster
delete the schema
mnesia:del_table_copy(schema, node@host.domain).