Thanks for your inputs Frank. On 07/26/2016 09:46 PM, Frank Filz wrote: > The current FSAL lock owner implementation is a void * (though the FSAL DOES > have visibility to the actual lock owner information if it needed to use > it). Anything more would only be needed if the underlying filesystem was > prepared to allow Ganesha to recover locks after a Ganesha crash. This would > actually be necessary for an absolutely correct FSAL_PROXY implementation, > unfortunately the NFS v4 protocol has limited provision for a client to > recover it's lost state. The implementations we have been making on > clustered filesystems have been to failover to another node and notify NFS > v3 clients of a crash, and allow NFS v4 clients to discover the crash, and > thus the clients reclaim the locks. Ideally, Ganesha as a cluster is able to > enforce grace period. > > So with all of that, there's no real need for anything more than a void * > pointer to the SAL state owner structure which provides the uniqueness of > the owner for the duration of it's validity within the system. If Ganesha > crashes, the underlying filesystem should dump state. If the protocol layer > invalidates the owner (lease expiry or whatever), then all state will have > been released and the owner no longer has meaning to the underlying > filesystem.
But what about the case where Ganesha process doesn't crash but still there could be failover/failback happening between two active ganesha servers(for eg., load-balancing). We ensure nfs-ganesha servers going to grace period using dbus commands. But then even though the clients try to reclaim their locks using their previous lock owner, since the state_owner struct is now changed, backend FS may assume it as a new lock request and may deny it as there is still old lock present with a different owner. Or does NFS-Ganesha duly unlocks all its existing locks whenever it enters grace-period either after hard reboot or via dbus? Thanks, Soumya ------------------------------------------------------------------------------ What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports.http://sdm.link/zohodev2dev _______________________________________________ Nfs-ganesha-devel mailing list Nfs-ganesha-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs-ganesha-devel
