[Info-vax] Clustering on VMS 4.7

[P. Sture]

In article 
<003df42b-e8d6-4135-a3bd-1a871766146b at 37g2000yqp.googlegroups.com>,
 H Vlems <hvlems at freenet.de> wrote:

> On 17 apr, 10:44, "P. Sture" <paul.sture.nos... at hispeed.ch> wrote:

> > I remember them well. There was also the case of the lock manager
> > occasionally finding its way onto one of the VAXstation 2000s, at which
> > point performance took a nose dive.
> >
> 
> Wasn't there LOCKDIRWT to prevent just that?

From:
 
<http://www2.openvms.org/kparris/HPTF2007_OpenVMS_Clusters_Theory_of_Oper
ation.pdf>

(beware URL wrapping)

PDF page 110:

"VAX/VMS version 5.0: 
Problem recognized: 
?In every cluster state transition, a Full Rebuild operation 
of the cluster-wide distributed lock database was 
required -- basically throwing away all Master copies of 
locks, selecting new resource masters, and then re- 
acquiring all locks, rebuilding the lock directory 
information in the process. This could take multiple 
minutes to complete." 

PDF Page 111:

"VAX/VMS version 5.2: 
Problem recognized: 
Resource mastership remains stuck on one node. 

Even if that node lost all interest in a resource tree, as long as there 
was even 1 lock anywhere in the cluster, that node remained the resource 
master. 

As nodes in a cluster rebooted one by one, the remaining nodes tended 
to accumulate resource mastership duties over time, resulting in 
unbalanced loads 

Solution: 
Resource tree remastering is introduced. Resource trees can now be 
moved between nodes. LOCKDIRWT parameter allows bias or 
³weighting² toward or away from specific nodes."

-- 
Paul Sture