[315] in Athena_Backup_System
Re: Jonathon Weiss: Re: Minutes of 19 Sept Meeting
daemon@ATHENA.MIT.EDU (delgado@MIT.EDU)
Thu Sep 26 18:51:02 1996
From: delgado@MIT.EDU
To: athena-backup@MIT.EDU
In-Reply-To: Your message of "Thu, 26 Sep 1996 11:21:56 EDT."
<9609261521.AA10131@chaos.MIT.EDU>
Date: Thu, 26 Sep 1996 18:50:54 EDT
Here are some alternatives to think about:
It seems that the vlserver interface supports a VL_GetAddrs
call which gets the ip address of all file servers.
We could fetch the address of all the fileservers, execute a
gethostby address call for each address and then do the server name
pattern match on the results.
We then do a VL_ListAttributes for the selected server names;
from there on we can pattern match any volume names.
--------------
VL_ListEntry at a time VS bulk fetch.
VL_ListEntry returns one entry at a time and performs a full
scan of the entire vldb. It provides the caller with information
whch is equvialent to a cursor, allowing him to fetch subsequent
entries. This implies the client makes one remote call per entry.
For fetch by server or server partition, the vlserver essentially
performs a full scan of the entire vldb to retireve matching vldb
entries in one call. What you are saving here is the over head of
issuing 20,000+ remote procedure calls to retrieve all volume entries.
I think we should do some performance testing to determine what
the impact is on each of the network, the client, and the vlservers.
