Re: [Kimchi-devel] [v3 1/1] Virtual machine migration
On 14-11-2014 07:04, simonjin wrote:
> The code above is running "self.conn.get().getInfo()"
more than once.
> You can store that value in a variable so you don't have to talk to
> libvirt multiple times.
> Actually, "self.conn" is used in more places later in the code, so
> that value can also be stored in a separate value. Try not to contact
> libvirt several times for the same information, it has a performance
> cost.
>
self.conn it self doesn't cost anything.
But there's no need to declare a function parameter if the function
doesn't use it.
> Usually we keep the model objects as instance variables. That
means
> that "vmhostdevs" should be declared in VMModel's constructor - along
> with many other model variables - as "self.vmhostdevs".
Due to the reason in code that VMHostDevsModel can't be imported at
the top of the class, the workaround is import and get the instance here.
Err, you're right, we have a huge dependency problem in the code right
now... So you should keep that.
> As I commented in the previous e-mail thread, the function
"add_task"
> will add the task to the object store. You don't need to do that.
>
Will need this to verify whether the vm is already in migration, right ?
You definitely need that task later to track the migration process but
the function "add_task" already stores the task in the object store. I
mean you shouldn't store it yourself because it's already done.
In order to check the migration task, you can lookup a task with the code:
task = taskmodel.lookup(taskid);
(where "taskmodel" is an instance of "TaskModel" and
"taskid" is the
Task ID)
if you have the Task ID, or:
alltasks = taskmodel.get_list()
if you don't have the ID and you want to inspect all tasks (probably
filtering by its 'target_uri' to find out which of them is related to
migration).