Maintenance socket path used for PGO is in the node workdir.
When the node workdir path is too long, the maintenance socket path
(workdir/cql.m) can exceed the Unix domain socket sun_path limit
and failing the PGO training pipeline.
To prevent this:
- pass an explicit --maintenance-socket override
pointing to a short determinitic path in /tmp derived from the MD5
hash of the workdir maintenance socket path
- update maintenance_socket_path to return the matching short path
so that exec_cql.py connects to the right socket
The short path socket files are cleaned up after the cluster stops.
The path is using MD5 hash of the workdir path, so it is deterministic.
Fixes SCYLLADB-1070
Closesscylladb/scylladb#29149
120f381a9d