On Wed, Apr 22, 2009 at 8:48 PM, Jason Edgecombe <[email protected]> wrote: > Steven Jenkins wrote: >> >> 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. >> >> As the sysvmq interface has two constraints - it can drop log >> messages if full and it has a limited message length - there is an >> audit_PrintStats() function which calls the relevant function in the >> audit interface module (the file interface doesn't need it as it >> doesn't have >> these constraints... it could log how many times it blocked in 'audit' >> though). An invocation of this function to the XCPU signal >> handler is added as well, so now we can see if there are any audit >> messages lost or truncated. >> >> Note that this patch has not been tested (or applied) against 1.4.10 >> or 1.5.x, so there may be some integration issues. If people think >> this patch is useful, we can clean it up and integrate it. >> > > Should this be added as a command-line parameter instead of a compile > parameter? > > I say this because you can switch from log files to syslog using a > command-line option. Can we run two or three logging options simultaneously? >
There is only support for one of message queues, log files, and syslog at a time. I think you have a valid point, though, about it being a run-time vs build-time option, and I can refactor the patch unless there are objections to doing so. > I'm not familiar with sysV message queues. > > Could you give a couple of usage cases? > On a linux system, you could consult the 'svipc' man page for additional information. Alternatively, you could look at a good reference on Unix (e.g., Richard Steven's Advanced Programming in the Unix Environment). Some areas where a queue is more useful than a file: - a message queue can have a maximum size, so you can be guaranteed that an errant process won't fill up your disks - message queues have a producer/consumer model, so your analyzer consumes messages -- that could be considered either a positive (e.g., more resource-friendly, easier to keep track of which messages have been processed, etc) or a negative (what if the consumer process dies? with a logfile, you can just restart the consumer; with message queues, once the messages are consumed, they are gone) -- Steven Jenkins End Point Corporation http://www.endpoint.com/ _______________________________________________ OpenAFS-devel mailing list [email protected] https://lists.openafs.org/mailman/listinfo/openafs-devel
