ravening commented on issue #3610: [WIP DO NOT MERGE] KVM: Rolling maintenance
URL: https://github.com/apache/cloudstack/pull/3610#issuecomment-573864393
 
 
   > ...
   > 
   > > We have a similar application to perform all these tasks and also a 
centralized dashboard to control upgrading hypervisors on all platforms in a 
different locations.
   > 
   > @ravening do you have this in public domain somewhere?
   > 
   We use this application in our company to upgrade all hypervisors in our 
platform. Its not public yet.
   > > Update:
   > > Nvm, I went through the code and understood what its doing. It enables 
maintenance mode on each individual hypervisor. This can be really bad in most 
cases because in the worst case a VM can be migrated multiple times
   > 
   > @ravening I cna safely say that at least all the VMs from the first host 
to be handled will be migrated multiple times. How is this bad? And how could 
this be avoided?
   @DaanHoogland In the worst case, a VM will be migrated twice. Once from the 
first hypervisor on which we start the upgrade to any random hypervisor and 
secondly from the hypervisor where it is already migrated to the upgraded 
hypervisor. This is any day better than rolling upgrade wherein worst case a VM 
can be migrated n-1 number of times.
   
   Im using findHostsForMigration to find a suitable host for migration which 
is already upgraded to migrate the vm. In this PR, the upgrade algo uses 
enableMaintenance command which can migrate VM to any non upgraded hypervisor.
   
   
   

----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
 
For queries about this service, please contact Infrastructure at:
[email protected]


With regards,
Apache Git Services

Reply via email to