Coda File System

random thoughts about modification logs

From: Ivan Popov <pin_at_medic.chalmers.se>
Date: Wed, 25 Feb 2004 12:30:14 +0100 (MET)
Hello,

recently I had some strange server crashes with my
"troublesome" volumes containing ~30000 objects, mostly symlinks...

Finally I copied all data to a new volume and deleted the old one.
At the same time I got rid of many unnecessary objects and
now I cannot tell if it is better because of less files, or
because of some evil corruption having been present in the old volume.

Anyway, I began to think of possible caveats and problem sources.

Let us see. Imagine a double replicated volume.
One of the servers can be remarkably slower than the other,
because of hardware or load.
If a client makes massive modifications, it will talk to the faster
server, never enter its own "yellow" or "red" zones and happily send
lots of data...
The faster server will try to send the logs to the other server which will
not be able to keep up with it ... some time later the volume modification
log will overflow.
Is it possible to have something like yellow/red zone detection
on server volume modification logs?

Just a thought.

Cheers,
--
Ivan
Received on 2004-02-25 06:35:54