Steven Jenkins wrote:
On Wed, Apr 22, 2009 at 9:20 PM, Russ Allbery <[email protected]> wrote:
Steven Jenkins <[email protected]> writes:
I just uploaded a preliminary patch to openafs-bugs (RT #124674) that
adds support to audit logs for Sys V message queues. In other words,
if you run this patch, instead of audit logs going to a file, they can
go to Sys V message queues. There is an additional option to
configure if you want to experiment with this: --with-audit-interface,
with two options: file and sysvmq, defaulting to file.
Out of curiosity, what do you get from message queues that you don't get
from a named pipe? No blocking if you have no reader?
You can choose to do non-blocking for named pipes. However, named
pipes (aka 'FIFO's to many in the Linux world) have a much tighter
coupling between producers and consumers than message queues do. For
example, if a writer tries to write to a named pipe that has no
readers, a SIGPIPE (or EPIPE if SIGPIPE is being ignored) is
generated
Sometimes, I need to get more debugging info after the fact. I'm just
wondering if queues function as a circular buffer when no readers are
present. I'm wondering how useful it would be to be able to get the
last X messages of maximum verbosity from a circular buffer. If
something of interest happens, then ask the service to dump the circular
buffer somewhere.
Granted, this doesn't come up often, and I'm not sure how this would be
better or worse than a memdump or something similar.
Just thinking out loud,
Jason
_______________________________________________
OpenAFS-devel mailing list
[email protected]
https://lists.openafs.org/mailman/listinfo/openafs-devel
