Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!apollo!pato
From: pato@apollo.HP.COM (Joe Pato)
Newsgroups: comp.sys.apollo
Subject: Re: rgyd dies occasionally
Message-ID: <5034b45a.20b6d@apollo.HP.COM>
Date: 6 Mar 91 17:54:00 GMT
References: <17465@milton.u.washington.edu>
Sender: root@apollo.HP.COM
Distribution: na
Lines: 55

In article <17465@milton.u.washington.edu>, etb@milton.u.washington.edu (Eric Bushnell) writes:
|> Has anybody else had their slave rgyd's die mysteriously?
|> It has happened a few times on 10.3 nodes on both token
|> ring and ether networks.
|> 
|> The rgyd_error_log reports the following: 
|> 

|> RGYD version 1.2, 89/10/06
|> Unable to rename database (network computing system/Registry Server Replication)
|> 
|> Checkpoint Task
|> Cannot rename files during checkpoint
|> 
|> No fault information available
|> ?(errlog) no fault information available (Debug/cross process traceback)

|> What's a checkpoint? What is it trying to rename, and why?
|> 
|> (Who's on first? 8-) )
|> 
|> Eric Bushnell
|> UW Civil Engr
|> etb@zeus.ce.washington.edu
|> etb@milton.u.washington.edu

This is a known (and infrequent) problem.  We plan to fix this in a future
release.

The checkpoint task wakes up periodically and writes any database changes
to the disk (each change is always written to the stable store update log - 
a checkpoint occurs when the actual database state is saved to disk and 
the update log is truncated).

During the checkpoint a form of 2PC (two phase commit) is used.  All the
database files are first written as foo.new and then when the database is
completely on disk, the file names are changed so that the new version
becomes current.  Finally the previous version of the files (now named
.bak) are removed since they are obsolete.  For some reason the rename()
call will sometimes yield an error and the server interprets this as a
catastrophic error.

We have never seen any damage due to this error - the server will properly
clean up the database files the next time it is restarted.

                    -- Joe Pato
                       Cooperative Computing Division
                       Hewlett-Packard Company
                       pato@apollo.hp.com


                    -- Joe Pato
                       Cooperative Computing Division
                       Hewlett-Packard Company
                       pato@apollo.hp.com