The test exercises all five node operations (bootstrap, replace, rebuild,
removenode, decommission) and by the end only one node out of four
remains alive. The CQL driver session, however, still holds stale
references to the dead hosts in its connection pool and load-balancing
policy state.
When the new_test_keyspace context manager exits and attempts
DROP KEYSPACE, the driver routes the query to the dead hosts first,
gets ConnectionShutdown from each, and throws NoHostAvailable before
ever trying the single live node.
Fix by calling driver_connect() after the decommission step, which
closes the old session and creates a fresh one connected only to the
servers the test manager reports as running.
Fixes: https://scylladb.atlassian.net/browse/SCYLLADB-1313.
Closesscylladb/scylladb#29306
In get_children we get the vector of alive nodes with get_nodes.
Yet, between this and sending rpc to those nodes there might be
a preemption. Currently, the liveness of a node is checked once
again before the rpcs (only with gossiper not in topology - unlike
get_nodes).
Modify get_children, so that it keeps a token_metadata_ptr,
preventing topology from changing between get_nodes and rpcs.
Remove test_get_children as it checked if the get_children method
won't fail if a node is down after get_nodes - which cannot happen
currently.
We want to be able to cancel decommission when it's still in the
tablet draining phase. Such a request is in a pending and paused
state, and can be safely canceled. We set the node's "draining" flag
back to false.
