I know this is an old thread but my update pertains to this.
The Data Collector service was also using a lot of memory (pretty much all of the memory I was giving the server). My server footprint wasn't that large (almost 400VMs, 15 HyperV Hosts, 6 Clusters) and I kept having to increase the memory of the server running Veeam One (started at 6GB, 8GB, 10GB, 16GB). The only fix was to restart the service every couple of days or just ignore it
Finally got around to making a Veeam support ticket after making the server "live". Short answer, support gave me a new executable and dlls and now a couple of days later and memory consumption is still under 1GB!!!!!!
Not sure if I can post the files here but I'm can at least put my case number if any of you want to try to reference that with support and get those files. I've asked if this fix will be in Update 2 of Veeam One but support tech was not able to confirm it.
Case # 02376866
Veeam One server is FINALLY usable