A couple of more bugs observed today:
1) stat-prefetch still causes glusterfs to die on occasion. I can
reproduce this with a bunch of clients doing a du of a complex directory
structure; out of 8 clients du'ing simultaneously, one or two will die
before the du finishes (glusterfs dies). This is probably the same thing
I've reported before about stat-prefetch, but I was hoping io-threads
might have been responsible (it wasn't).
2) NFS reexport is somehow triggering a really rapid memory
leak/consumption in glusterfsd, causing it to quickly die. On the NFS
client, I did a du of an Ubuntu Edgy mirror, which worked fine. Then I
did multiple cp -a's of a simple 30MB directory, which causes rapid memory
consumption on the glusterfsd of node1 of an AFR. It soon dies (before it
does the sixth copy), along with the NFS-exported glusterfs client
(running on node1, as well). This occurs in a simple mirror with
storage/posix and protocol/server on the server and protocol/client,
cluster/afr, performance/read-ahead, and performance/write-behind on the
client.
Thanks,
Brent
On Fri, 27 Apr 2007, Brent A Nelson wrote:
Hmm, it looks like io-threads is responsible for more than just mtime
glitches when used with write-behind. I just found that the problems I had
with NFS re-export go away when I get rid of io-threads (plus, now that I can
enable write-behind, the NFS write performance is far better, by at least a
factor of 5)!
It looks like I'll be switching off io-threads for now, and turning on all
the other performance enhancements.
Thanks,
Brent
On Fri, 27 Apr 2007, Brent A Nelson wrote:
On Thu, 26 Apr 2007, Anand Avati wrote:
Brent,
I understand what is happening. It is because I/O threads lets the
mtime overtake the write call. I assume you have loaded io-threads on
server side (or below write-behind on client side).
Yes, I have io-threads loaded on the server. This occurs when I load
write-behind on the client.
I could provide you a temporary 'ugly' fix just for you if the issue is
critical (until the proper framework comes in 1.4)
It would be worthwhile if the temporary fix is acceptable for the 1.3
release (otherwise, you'll need a warning included with the release, so
that people enabling io-threads and write-behind know what to expect), but
don't waste your time if it's just for me. Push on to 1.4 and the real
fix; I'll just leave write-behind disabled for now.
Many Thanks,
Brent
