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From kishore g <g.kish...@gmail.com>
Subject Re: Is there any way to force controller to re-elect leader
Date Tue, 08 Dec 2015 00:05:32 GMT
Cool. Glad to see it worked.
On Dec 7, 2015 3:57 PM, "Hang Qi" <hangq.1985@gmail.com> wrote:

> Hi Kishore,
>
> Thanks very much for your detailed instructions, I tried it on my test
> cluster, it works!
>
> Thanks
> Hang Qi
>
> On Wed, Dec 2, 2015 at 12:54 PM, kishore g <g.kishore@gmail.com> wrote:
>
>> Here are the steps. Please try them on a dummy cluster
>>
>> Lets call the existing cluster - ServingCluster. First we create a new
>> cluster called SuperCluster
>>
>> helix-admin.sh createCluster SuperCluster
>>
>> Now add controller nodes C1, C2, C3 as participants to SuperCluster
>>
>> helix-admin.sh addInstance SuperCluster C1
>> helix-admin.sh addInstance SuperCluster C2
>> helix-admin.sh addInstance SuperCluster C3
>>
>> Add a resource named after original cluster, ServingCluster. This
>> resource can be set up in any mode.
>>
>> AUTO ---> one of C1, C2, C3 will start managing ServingCluster
>> SEMI_AUTO - leader is selected based on the preference list. If you want
>> C2 to be the leader, set it to C2, C3, C1. If C2 crashes, C3 will take over
>> automatically.
>> CUSTOM- > you get complete control here, if you want to C2  to control
>> the ServingCluster, set the IS as follows. Note: there is not automatic
>> re-election of leader in this case.
>>
>> C1:STANDBY,
>> C2:LEADER,
>> C3:STANDBY
>>
>> Stop all controllers. Restart them in distributed mode, and this time the
>> cluster name you provide to start will be SuperCluster.
>>
>> Hope this helps.
>>
>> Once you test your changes, you can go back to standalone mode by simply
>> restarting the controllers again in standalone mode and provide the
>> ServingCluster as the clustername.
>>
>> Hope this helps.
>>
>> Try this out on a dummy cluster.
>>
>> thanks,
>> Kishore G
>>
>>
>> On Wed, Dec 2, 2015 at 12:07 PM, Hang Qi <hangq.1985@gmail.com> wrote:
>>
>>> Hi Kishore,
>>>
>>> Thanks very much for your response.
>>>
>>> We are using Standalone mode.
>>>
>>> Do you have any instructions how to convert controllers from standalone
>>> to distributed mode, I can not find it in
>>> http://helix.apache.org/0.6.5-docs/tutorial_controller.html
>>>
>>> Thanks
>>> Hang Qi
>>>
>>> On Wed, Dec 2, 2015 at 11:55 AM, kishore g <g.kishore@gmail.com> wrote:
>>>
>>>> What is the mode in which controller is deployed?
>>>>
>>>> Standalone or Distributed.
>>>>
>>>> Standalone is the mode where we run 3 controllers independently and one
>>>> of them becomes the leader and starts managing.
>>>>
>>>> In Distributed, the controllers are participant of another super
>>>> cluster and cluster to manage will become a resource in the super cluster.
>>>> This mode is useful when there are too many clusters and we dont need to
>>>> bring up controllers for each cluster.
>>>>
>>>> What you want can be achieved easily with distributed mode. You can
>>>> enable/disable controllers since they come participants of super cluster.
>>>>
>>>> I cant think of a straight forward way to achieve that in standalone
>>>> mode.
>>>>
>>>> Another option is to convert controllers from standalone to
>>>> distributed. This can be done without causing any interruption to running
>>>> servers.
>>>>
>>>>
>>>> On Wed, Dec 2, 2015 at 11:16 AM, Hang Qi <hangq.1985@gmail.com> wrote:
>>>>
>>>>> Hi All,
>>>>>
>>>>> Is there any way to force controller to re-elect leader, or one step
>>>>> further, is there any way we can force particular controller to be the
>>>>> leader?
>>>>>
>>>>> The reason I am asking is that we are using customized rebalancer, and
>>>>> we need to update all the controllers to let the controller to use the
new
>>>>> code, it is not very bucket testing friendly.
>>>>>
>>>>> Thanks
>>>>> Hang Qi
>>>>>
>>>>>
>>>>
>>>
>>>
>>> --
>>> Qi hang
>>>
>>
>>
>
>
> --
> Qi hang
>

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