Problems with writing client data while running several clients

[Rolf Schrittenlocher <Schrittenlocher (at) rz.uni-frankfurt.de>]

Hi,

we are running 1 to 3 clients on each host, one for $hostname and one 
for each virtual host defined on the machine in order to get client data 
like disk, cpu, etc. for $hostname and for each virtual host. Each 
client is started using
$HOBBITCLIENTHOME/bin/hobbitlaunch 
--config=$HOBBITCLIENTHOME/etc/clientlaunch.${MACHINE}.cfg 
--log=$HOBBITCLIENTHOME/logs/clientlaunch.${MACHINE}.log 
--pidfile=$HOBBITCLIENTHOME/logs/clientlaunch.${MACHINE}.pid

Now I have the problem that client data of one or both clients is 
neglected by the server. In rrd-data.log it shows:
2006-01-18 13:03:40 RRD error updating 
/pica/ffm/com/sys/hobbit/hobbit/data/rrd/lbscgi2/netstat.rrd from 
141.2.164.215: illegal attempt to update using time 1137585820 when last 
update time is 1137585820 (minimum one second step)
In rrd-status.log are similar entries like
2006-01-18 12:48:38 RRD error updating 
/pica/ffm/com/sys/hobbit/hobbit/data/rrd/lbscgi2/memory.real.rrd from 
141.2.164.215: illegal attempt to update using time 1137584918 when last 
update time is 1137584918 (minimum one second step)

The client data (disk, etc) for both becomes purple in bb.html.
Date for both clients is stored (sometimes) correctly:
hobbit/hobbit/data/rrd/otter
-rw-r--r--   1 bb       prod       19576 Jan 18 12:43 memory.real.rrd
hobbit/hobbit/data/rrd/lbscgi2
-rw-r--r--   1 bb       prod       19576 Jan 18 12:58 memory.real.rrd

I tried starting the clients with some seconds difference, that helps 
for a certain time and then the problem reappears. What can I do?

kind regards
Rolf

--
Mit freundlichen Gruessen
Rolf Schrittenlocher

HRZ/BDV, Senckenberganlage 31, 60054 Frankfurt 
Tel: (49) 69 - 798 28908   Fax: (49) 69 798 2881
LBS: lbs-f (at) mlist.uni-frankfurt.de
Persoenlich: schritte (at) rz.uni-frankfurt.de