Clustered Samba Challenges and Directions

Clustered Samba together with ctdb have been successful together for many years now. This talk will present latest developments in Samba and ctdb from the Samba perspective. It is directed towards implementors of Samba in clustered storage products, as well as developers interested in the challenges the SMB protocol carries in clustered environments.

* Performance / Scalability
The core ctdb engine is one single threaded daemon per cluster node. Samba will take over clusterwide messaging from ctdb.

* Stability
Samba has an inherent potential for deadlocking: Smbd in many situations has to lock more than one tdb file simultaenously. Samba itself has proper locking hierarchies, but if other components like file systems and ctdb can also take locks and block, things become messy. Samba will offer changes such that no more than one kernel-level lock will be taken at a time.

* Databases for Persistent file handles
To implement clusterwide persistent file handles, Samba needs a middle ground between completely volatile databases that can go away with a cluster node and persistent databases that need to survive node crashes. Based on the database restructuring work mentioned above, Samba will enable a new database consistency model to enable persistent file handles.

Learning Objectives

Status update for clustered
Samba Infrastructure challenges in ctdb and Samba
New directions of development in clustered Samba