[ 
https://issues.apache.org/jira/browse/CLOUDSTACK-10326?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16510477#comment-16510477
 ] 

ASF GitHub Bot commented on CLOUDSTACK-10326:
---------------------------------------------

blueorangutan commented on issue #2493: CLOUDSTACK-10326: Prevent hosts fall 
into Maintenance when there are running VMs on it
URL: https://github.com/apache/cloudstack/pull/2493#issuecomment-396779895
 
 
   @nvazquez a Trillian-Jenkins test job (centos7 mgmt + kvm-centos7) has been 
kicked to run smoke tests

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


> Prevent hosts fall into Maintenance when there are running VMs on it
> --------------------------------------------------------------------
>
>                 Key: CLOUDSTACK-10326
>                 URL: https://issues.apache.org/jira/browse/CLOUDSTACK-10326
>             Project: CloudStack
>          Issue Type: Bug
>      Security Level: Public(Anyone can view this level - this is the 
> default.) 
>    Affects Versions: 4.11.0.0
>            Reporter: Nicolas Vazquez
>            Assignee: Nicolas Vazquez
>            Priority: Major
>             Fix For: 4.11.1.0
>
>         Attachments: CLOUDSTACK-10326-Debug.png, 
> CLOUDSTACK-10326-InitialState.png, CLOUDSTACK-10326-Migrating.png, 
> CLOUDSTACK-10326-MigrationFailed.png
>
>
> This issue was discovered, fixed and tested on KVM, but applies for every 
> hypervisor.
> h2. Background
> When enabling maintenance mode in a host, host state is put into 
> 'PrepareForMaintenance' and running VMs are migrated into another host. After 
> every VM is migrated, host goes to 'Maintenance' state.
> Checks are performed on ResourceManagerImpl.checkAndMaintan() method:
>  * List VMs with host_id = HOST_ID
>  * List VMs with last_host_id = HOST_ID and state=Migrating
> When both queries are empty, then the host can be put into Maintenance.
> When a VM is being migrated to DEST_HOST, its host_id column is set to 
> DEST_HOST, last_host_id = ORIGIN_HOST and state = Migrating. If then 
> migration fails, host_id = last_host_id = ORIGIN_HOST 
> h2. Issue
> This sequence:
>  * Enable maintenance mode on ORIGIN_HOST
>  * VMs start being migrated to a host, say DEST_HOST
>  * checkAndMaintain() starts:
>  ** First check passes (no VM with host_id = ORIGIN_HOST_ID as those are 
> being migrated)
>  ** Before the second check, one or more migrations fail
>  ** Second check passes, however there are VMs running on the host as 
> migrations have failed.
>  * Host goes into Maintenance state.
> Screenshots attached, query executed on each case:
> select id, name, instance_name, state, host_id, last_host_id from vm_instance;



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

Reply via email to