sumSeries() function not working as expected

[potchin]

This is an odd one. I have a graph which shows traffic to a wildcard number of webservers (currenly 2) and aggregate them using the sumSeries() function to give me total number of hits across all servers.The servers are currently active/backup so only one server will handle traffic at a time. This morning we failed the servers over so traffic moved from the primary to the secondary node.

The traffic for the system is around 11-12k requests/min but if the sumSeries() function is active the traffic shows as double before the failover...

If I remove the sumSeries() function the data points look correct...

Whats stranger still is that if I zoom into a time before the failover but with the sumSeries() function active I see the correct traffic level (12k, not ~24k).

Is this a bug or am I missing something?

[alexanderzobnin]

Looks like a bug in sumSeries() function.

[Cbryndum]

Not to highjack the thread but if you are using stacked graphs with sumSeries() and one of the metrics doesnt return a value the stacked graph goes eschew.

If i disable the "bad" metric it works