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Posted to user@ambari.apache.org by Aaron Cody <ac...@hexiscyber.com> on 2014/03/25 01:17:35 UTC

role dependency question

I have two components, A and B
B requires A to be running while it installs…
Q: is there a way to express this in the role-dependencies?   (I know how to say ‘A must run before B can run’ .. or ‘A must be installed before B is installed’, but how about ‘A must be running before installing B’)

TIA


Re: role dependency question

Posted by Siddharth Wagle <sw...@hortonworks.com>.
We use Role Command order to figure out what can be run in parallel within
a stage and what cannot.

However, we do Install and Start as separate stages, the Start / Stop API
calls are designed to do State transitions which effectively mean create
Start stage after and Install stage is successful.

So, looking at the RoleCommandOrder.java, there does not seem to be
anything stopping you from adding that dependency, I might be wrong with a
cursory look, but still that would not help with achieving what you are
trying to do since those tasks will be part of separate Stages.

Could you open a Jira for this with some use case documentation? The use
case would really help with the discussion flow.

Best Regards,
Sid


On Fri, Mar 28, 2014 at 3:10 PM, Yusaku Sako <yu...@hortonworks.com> wrote:

> AFAIK, we currently don't have a way to express "A must be running
> before installing B".
> Perhaps others can chime in.
> BTW, which specific components do you have in mind?
>
> Yusaku
>
> On Mon, Mar 24, 2014 at 5:17 PM, Aaron Cody <ac...@hexiscyber.com> wrote:
> > I have two components, A and B
> > B requires A to be running while it installs...
> > Q: is there a way to express this in the role-dependencies?   (I know
> how to
> > say 'A must run before B can run' .. or 'A must be installed before B is
> > installed', but how about 'A must be running before installing B')
> >
> > TIA
> >
>
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Re: role dependency question

Posted by Yusaku Sako <yu...@hortonworks.com>.
AFAIK, we currently don't have a way to express "A must be running
before installing B".
Perhaps others can chime in.
BTW, which specific components do you have in mind?

Yusaku

On Mon, Mar 24, 2014 at 5:17 PM, Aaron Cody <ac...@hexiscyber.com> wrote:
> I have two components, A and B
> B requires A to be running while it installs...
> Q: is there a way to express this in the role-dependencies?   (I know how to
> say 'A must run before B can run' .. or 'A must be installed before B is
> installed', but how about 'A must be running before installing B')
>
> TIA
>

-- 
CONFIDENTIALITY NOTICE
NOTICE: This message is intended for the use of the individual or entity to 
which it is addressed and may contain information that is confidential, 
privileged and exempt from disclosure under applicable law. If the reader 
of this message is not the intended recipient, you are hereby notified that 
any printing, copying, dissemination, distribution, disclosure or 
forwarding of this communication is strictly prohibited. If you have 
received this communication in error, please contact the sender immediately 
and delete it from your system. Thank You.