Count the null values for the average enrichers

[Valentin Aitken <va...@cloudsoftcorp.com>]

Hi,

I am writing you for an issue which I hit in the 
TomcatAutoScalerPolicyTest .
I made a pull request 
<https://github.com/apache/incubator-brooklyn/pull/731> about this, but 
we think it should be changed globally.
https://github.com/apache/incubator-brooklyn/pull/731

Here is the use case:
The test makes two requests to the newly created one node cluster.
On the second request the avarage enricher for REQUEST_COUNT_PER_NODE 
gets to two and since it has attached scaling policy in the test which 
requires between 0 and 1 average value, scale up is triggered immediately.

On the next update after scaling is triggered the REQUEST_COUNT_PER_NODE 
is again 2
since the REQUESTS for the previously created is null and it is missed 
in the count aggregation will again return 1
which will result again in scaling up.

So please share your opinion on this and vote if you want to use 0 for 
defaultValueForUnreportedSensors for the average enricher.

Thank you,
Valentin!

-- 
Cloudsoft Corporation Limited, Registered in Scotland No: SC349230. 
 Registered Office: 13 Dryden Place, Edinburgh, EH9 1RP
 
This e-mail message is confidential and for use by the addressee only. If 
the message is received by anyone other than the addressee, please return 
the message to the sender by replying to it and then delete the message 
from your computer. Internet e-mails are not necessarily secure. Cloudsoft 
Corporation Limited does not accept responsibility for changes made to this 
message after it was sent.

Whilst all reasonable care has been taken to avoid the transmission of 
viruses, it is the responsibility of the recipient to ensure that the 
onward transmission, opening or use of this message and any attachments 
will not adversely affect its systems or data. No responsibility is 
accepted by Cloudsoft Corporation Limited in this regard and the recipient 
should carry out such virus and other checks as it considers appropriate.