What if head node fails in DUCC

["reshu.agarwal" <re...@orkash.com>]

Hi,

I have a question. If head node fails then we are no more able to do 
UIMA processing. Can I defined multiple head nodes in DUCC? If one head 
node is failed then second node will work as a head node. Is this 
possible? what is the backup strategy of DUCC?

-- 
Thanks,
Reshu Agarwal

Re: What if head node fails in DUCC

[Eddie Epstein <ea...@gmail.com>]

Each job has a job driver. All job drivers and job processes not running on
the head node continue working as long as the DUCC broker is still viable,
and an AMQ broker can easily be configured in master/slave configuration.

Similarly, DUCC service processes and reservation processes not running on
the head node are unaffected.

Eddie


On Tue, Apr 1, 2014 at 8:26 AM, reshu.agarwal <re...@orkash.com>wrote:

> On 04/01/2014 05:28 PM, Eddie Epstein wrote:
>
>> Correct. Most DUCC daemons running on the head node are restartable. We
>> expect to complete this work so that in the case of head node failure a
>> new
>> head node can automatically be started.
>>
>> Currently DUCC can be configured such that no active user work is affected
>> if a head node goes down. However, without the head node no new user
>> processes are created.
>>
>> Eddie
>>
>>
>> On Tue, Apr 1, 2014 at 1:42 AM, reshu.agarwal <re...@orkash.com>
>> wrote:
>>
>>  Hi,
>>>
>>> I have a question. If head node fails then we are no more able to do UIMA
>>> processing. Can I defined multiple head nodes in DUCC? If one head node
>>> is
>>> failed then second node will work as a head node. Is this possible? what
>>> is
>>> the backup strategy of DUCC?
>>>
>>> --
>>> Thanks,
>>> Reshu Agarwal
>>>
>>>
>>>  Hi Eddie,
>
> Sorry I did not get you. What do you mean by this, "Currently DUCC can be
> configured such that no active user work is affected if a head node goes
> down. "?
>
> As I understand if a node goes down or crashed then all the processes
> which are running on this node will terminate. So, big question is, "How
> DUCC ensures no active user work is affected if head node goes down?"
>
> --
> Thanks,
> Reshu Agarwal
>
>

Re: What if head node fails in DUCC

["reshu.agarwal" <re...@orkash.com>]

On 04/01/2014 05:28 PM, Eddie Epstein wrote:
> Correct. Most DUCC daemons running on the head node are restartable. We
> expect to complete this work so that in the case of head node failure a new
> head node can automatically be started.
>
> Currently DUCC can be configured such that no active user work is affected
> if a head node goes down. However, without the head node no new user
> processes are created.
>
> Eddie
>
>
> On Tue, Apr 1, 2014 at 1:42 AM, reshu.agarwal <re...@orkash.com>wrote:
>
>> Hi,
>>
>> I have a question. If head node fails then we are no more able to do UIMA
>> processing. Can I defined multiple head nodes in DUCC? If one head node is
>> failed then second node will work as a head node. Is this possible? what is
>> the backup strategy of DUCC?
>>
>> --
>> Thanks,
>> Reshu Agarwal
>>
>>
Hi Eddie,

Sorry I did not get you. What do you mean by this, "Currently DUCC can 
be configured such that no active user work is affected if a head node 
goes down. "?

As I understand if a node goes down or crashed then all the processes 
which are running on this node will terminate. So, big question is, "How 
DUCC ensures no active user work is affected if head node goes down?"

-- 
Thanks,
Reshu Agarwal

Re: What if head node fails in DUCC

[Eddie Epstein <ea...@gmail.com>]

Correct. Most DUCC daemons running on the head node are restartable. We
expect to complete this work so that in the case of head node failure a new
head node can automatically be started.

Currently DUCC can be configured such that no active user work is affected
if a head node goes down. However, without the head node no new user
processes are created.

Eddie


On Tue, Apr 1, 2014 at 1:42 AM, reshu.agarwal <re...@orkash.com>wrote:

>
> Hi,
>
> I have a question. If head node fails then we are no more able to do UIMA
> processing. Can I defined multiple head nodes in DUCC? If one head node is
> failed then second node will work as a head node. Is this possible? what is
> the backup strategy of DUCC?
>
> --
> Thanks,
> Reshu Agarwal
>
>