Cluster service should not access SAKAI_SESSION table directly
GENERAL
TESTING
GENERAL
TESTING
Description
cluster/cluster-impl/impl/src/java/org/sakaiproject/cluster/impl/SakaiClusterService.java accesses the SAKAI_SESSION table directly, in the maintenance thread which removes sessions from servers no longer active.
This is fragile code which would break if an alternate non-db session implementation was used.
To fix this, cleanup of sessions should be delegated to the session service - cluster should pass the serverIds of expired servers to session to explicitly remove sessions for those servers.
It should also be possible to pass a list of all active sessions to allow the session service to remove anything else, though this may need some locking mechanism to avoid race conditions with servers entering the cluster getting their sessions removed.
The changes for this JIRA are an improvement - session and lock cleanup code works better than previously, verified on 2-5-x production system.
However, cluster still contains a reference to SAKAI_SESSION in the lock cleanup code - architecturally, neither SAKAI_LOCKS nor SAKAI_SESSION should be referenced directly by cluster (as SAKAI_LOCKS is owned by the db module).
This may need to be addressed when/if the session and cluster handling code moves to a message- rather than db-based architecture.
cluster/cluster-impl/impl/src/java/org/sakaiproject/cluster/impl/SakaiClusterService.java accesses the SAKAI_SESSION table directly, in the maintenance thread which removes sessions from servers no longer active.
This is fragile code which would break if an alternate non-db session implementation was used.
To fix this, cleanup of sessions should be delegated to the session service - cluster should pass the serverIds of expired servers to session to explicitly remove sessions for those servers.
It should also be possible to pass a list of all active sessions to allow the session service to remove anything else, though this may need some locking mechanism to avoid race conditions with servers entering the cluster getting their sessions removed.