[hobbit] Xmon 4.3 - serious RRD update problem?

[Dominique Frise]

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