[Linux-cluster] DLM: lock timeout and deadlock detection

[Hua Zhong]

Hi list:

I've recently started to read about the Redhat's implementation of DLM
that David posted on LKML. I've few questions:

1. There is no lock timeout imeplemented (at least from API point of
view). Is this something you plan to add? Is there any draft of the
design?
2. With no lock timeout in DLM, how does upper-layer applications
(like GFS) implement such lock timeout (or does GFS also have no
timeout)? One thought is that it could has its own timer and when it
expires just cancel the pending lock.
3. How much does DLM do wrt deadlock detection? Especially when it
doesn't have timeout. Is it solely the application's responsibility to
detect it?
4. This is not a technical question. I'm trying to convince our
management to use DLM, so I'd like to know how stable it is and on
what kind of scale the Redhat clustering solution is being used by the
enterprise. Is it stable enough in production (data like average
uptime, etc)?

Thanks for your help.

Hua