[Xymon] Problems generating graphs with xymonproxy between client and server

[Sven Schuster]

(shame on me, forgot to change mail format to plain text)

Hello,
in the local setup I've recently switched from clients talking to xymon server directly to clients sending their checks via xymonproxy. Used xymon versions (client, proxy and server) are 4.3.28.
What could be observed now was that graphs generated from status messages (via NCV_XXX configuration) are missing values most of the time since switching to the xymon proxies.
Further investigation revealed that the most probable cause might be that when xymonproxy combines multiple statuses into one combo, the xymon server won't handle them the same way as normal single status messages, e.g. not handing them over to the status channel/xymond_rrd.
As this behaviour isn't configurable in xymonproxy, I've tested setting COMBO_DELAY in xymonproxy.c to 1000, virtually disabling generation of combos from incoming messages. After recompiling and rolling out the new binary, it showed that this indeed fixed the problem, graphs where generated as expected again.
 
Has anybody stumbled across this behaviour yet? Is there another fix than setting the hardcoded COMBO_DELAY limit thus disabling combo messages from xymonproxy? IMO a real fix might be to let xymonproxy generate extcombos instead of combos, but this seems a non-trivial task to do?!

Kind regards,
Sven