Ohara: OharaStream 0.4 release

[konekoya]

What should be done during the 0.4 release:

• [x] Create 0.4 branch (base on last commit of the frozen day -> 5/5)
• [x] Update ohara's master branch version to 0.5-SNAPSHOT
• [ ] Remove unused (or unnecessary) functions from 0.4 branch
• [x] deploy to demo environment
• [x] Add a change log in release wiki page
• [x] Update version of 0.4 branch to 0.4.0
• [x] Update Bintray repo
• [x] Add tags in release wiki page
• [x] Add 0.4 binaries to GitHub download

release link

[chia7712]

@konekoya Could we highlight the feature of 0.4 release? For example, metrics APIs, shabondi prototype, and developer docs

[konekoya]

Such a good idea. I'll include a summary in the release note

[konekoya]

@chia7712 I've updated the release note. Would love to hear your feedback on this update :)

[chia7712]

@konekoya could you add more description to the new features?

• Metrics APIs: ohara supports jmx servcie now! Both connector APIs and topic APIs are able to fetch the metrics for you. For custom connector developers, you can leverage the counter (see docs for more details) to expose your custom metrics.

[konekoya]

This is great! Added

[chia7712]

@jackyoh @saivirtue Please offer some words for @konekoya. We ought to make our release announcement more readable and friendly.

[chia7712]

• Developer docs: the official guide is online now. Ohara welcome and encourage all connector/streampp developers to read it.

[saivirtue]

@konekoya help to improve sentence fluency, thanks :)

• Support multiple instances for streamApp
• Use different environment between docker and kubernetes in Pipeline without any influence except using different parameters in configurator. See use docker and use kubernetes

[vitojeng]

• Shabondi prototype: Shabondi is a data proxy which can receive streaming dataset from http request into a Pipeline.

[konekoya]

Thanks everyone for the help! Ohara stream 0.4.0 has been released :)

[chia7712]

@konekoya https://github.com/oharastream/ohara/releases is still in draft???