Startable entity does not get "on fire" if exception is thrown within start()

[Michael Schneider <Mi...@virtustream.com>]

Hi!

I have a Startable entity. I have found that if an exception is thrown within the start() method, the entity still gets green at the end.

Question 1: Is this intended behavior, and if so, why?

Question 2: What options do I have to force the entity into state "on fire" if any unhandled exception is thrown in start()?

Regards,
Michael

Michael Schneider
Senior Software Engineer

Virtustream Inc.
6 Concourse Parkway | Suite 1930 | Atlanta | GA 30328
Cell: +49 (176) 24102310
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Re: Startable entity does not get "on fire" if exception is thrown within start()

[Sam Corbett <sa...@cloudsoftcorp.com>]

Hi Michael,

Question 1:

I agree with you that this behaviour is surprising.

I'm going to guess that you are using BasicStartableImpl. Its
implementation of `start` should be modified to follow the same pattern as
entities that extend `brooklyn.entity.basic.SoftwareProcess`, which defers
to a class called MachineLifecycleEffectorTasks. This class' `start` method
transitions through "starting" and "started" states. If an exception is
thrown it sets the entity "on fire" and before propagating the exception.

See this link for the implementation:
https://github.com/apache/incubator-brooklyn/blob/d7ac3ac11d70b0ba1b6e3f5d7cbcd5d1615bbd33/software/base/src/main/java/brooklyn/entity/software/MachineLifecycleEffectorTasks.java#L232-242



Question 2:

To set the state of an entity you should follow pattern shown in the link
above. For example, to have an entity set itself "on fire":

        ServiceStateLogic.setExpectedState(this, Lifecycle.ON_FIRE);

The value of using this indirection (rather than directly calling
`entity.setAttribute(Attributes.SERVICE_STATE_ACTUAL, Lifecycle.ON_FIRE)`)
is that it will track metadata around state transitions like the date and
time they occur.


I will look at updating BasicStartableImpl.

I hope this helps,

Sam



On 2 July 2015 at 15:40, Michael Schneider <
Michael.Schneider@virtustream.com> wrote:

> Hi!
>
> I have a Startable entity. I have found that if an exception is thrown
> within the start() method, the entity still gets green at the end.
>
> Question 1: Is this intended behavior, and if so, why?
>
> Question 2: What options do I have to force the entity into state "on
> fire" if any unhandled exception is thrown in start()?
>
> Regards,
> Michael
>
> Michael Schneider
> Senior Software Engineer
>
> Virtustream Inc.
> 6 Concourse Parkway | Suite 1930 | Atlanta | GA 30328
> Cell: +49 (176) 24102310
> michael.schneider@virtustream.com<ma...@virtustream.com>
> | www.virtustream.com<http://www.virtustream.com/>
>
> Keep up with Virtustream:
> Blog<http://www.virtustream.com/blog/> * Twitter<
> https://twitter.com/#%21/virtustream> * LinkedIn<
> http://www.linkedin.com/company/virtustream> * Slideshare<
> http://www.slideshare.net/Virtustream> * YouTube<
> http://www.youtube.com/user/Virtustream>
>
> The information contained in this electronic mail transmission may be
> privileged and confidential, and therefore, protected from disclosure. If
> you have received this communication in error, please notify us immediately
> by replying to this message and deleting the email and its attachments from
> all computers without copying or disclosing it.
>

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