Alan Sparks wrote:
Testing Xymon 4.3 beta2 on CentOS 4.7 (x86_64 and i686) systems. I've noticed the updates to RRD files are not synchronized to disk in a timely manner. For instance, for a random host, the rrd files list as follows:
-rw-r--r-- 1 hobbit hobbit 38624 Jun 12 17:10 ifstat.eth0.1005.rrd -rw-r--r-- 1 hobbit hobbit 38624 Jun 12 16:50 ifstat.eth0.rrd -rw-r--r-- 1 hobbit hobbit 19640 Jun 12 17:00 la.rrd -rw-r--r-- 1 hobbit hobbit 19640 Jun 12 17:05 memory.actual.rrd -rw-r--r-- 1 hobbit hobbit 19640 Jun 12 17:20 memory.real.rrd -rw-r--r-- 1 hobbit hobbit 19640 Jun 12 17:25 memory.swap.rrd -rw-r--r-- 1 hobbit hobbit 304400 Jun 12 17:40 netstat.rrd
There is a huge disparity in timestamps on these files. Curiously, if I refresh the trends page for the host a time or two, the files will suddenly come up to date. I assume there is some write caching behavior in some part of Xymon that is not flushing data until a timeout, or until (perhaps) something tells it to?
This causes graphs to have some missing data until the user hits refresh. Also, we use DRRAW, which will not see timely updates. Is this a known issue in the beta?
This is a rather a feature that can be disabled. See http://www.hswn.dk/hobbiton/2009/02/msg00186.html
Dominique