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Hi list,

last week we upgraded our Mitaka cloud to Ocata (via Newton, of  
course) with ceph backend, and also upgraded the cloud nodes from  
openSUSE Leap 42.1 to Leap 42.3. There were some issues as expected,  
but no showstoppers (luckily).
So the cloud is up and working again, but our monitoring shows a high  
CPU load for cinder-volume service on the control node. But since all  
the clients are on the compute nodes we are wondering what cinder  
actually does on the control node except initializing the connections  
of course. I captured a tcpdump on control node and saw a lot of  
connections to the ceph nodes, the data contains all these rbd_header  
files, e.g. rb.0.24d5b04[...]. I expect this kind of traffic on the  
compute nodes, of course, but why does the control node also establish  
so many connections?

I'd appreciate any insight!

Regards,
Eugen

-- 
Eugen Block                             voice   : +49-40-559 51 75
NDE Netzdesign und -entwicklung AG      fax     : +49-40-559 51 77
Postfach 61 03 15
D-22423 Hamburg                         e-mail  : eblock at nde.ag

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