[collectd] Some data is being collected twice in a short time span?

[Elliot]

Hi!

I've noticed that sometimes data of the same type instance could be 
collected twice in a short time span. For instance, my program could 
receive the following binary data from collectd:

[(8, 1561609235.63349), (2, 'cpu'), (3, '0'), (4, 'cpu'),
(5, 'system'), (6, [(2, 297502)]),         /* FIRST COLLECT */
(8, 1561609235.6335657), (5, 'softirq'), (6, [(2, 122952)]), (8, 
1561609235.6335669), (5, 'steal'), (6, [(2, 0)]), (8, 
1561609235.6335678), (5, 'idle'), (6, [(2, 1921056)]), (8, 
1561609235.6345353), (5, 'user'), (6, [(2, 254032)]),
(8, 1561609235.6345372), (5, 'system'),    /* SECOND COLLECT */
(6, [(2, 297510)]), (8, 1561609235.634538), (5, 'wait'), (6, [(2, 
21160)]), (8, 1561609235.634539), (5, 'nice'), (6, [(2, 342)]), (8, 
1561609235.63454), (5, 'interrupt'), (6, [(2, 0)]), ...

As you could see, 'system' was collected twice at 1561609235.63349 and 
1561609235.6345372.

This doesn't happen often. Maybe once every few hours.

This seems not a big deal, but it is causing some confusion in my 
parsing program.

Is this normal? Should my parser expect to deal this? Or is there 
something wrong with my set up?

Thanks for your help!

-- 
Elliot