Virgo/Community/F2F/F2F Nov 2010

Virgo F2F November 2010 (now completed)

The objective of this meeting was to plan and coordinate future work on Virgo.

There was also time to cover various aspects of how Virgo development is done for the benefit of contributors and committers-to-be.

There was a light-hearted journal kept of the events of this week.

Brainstorming mind-maps are available here.

Attendees were:

• Chris Frost (SpringSource/VMware)
• Violeta Georgieva (SAP)
• Hristo Iliev (SAP)
• Borislav Kapukaranov (SAP)
• Glyn Normington (SpringSource/VMware) (who led the meeting and took minutes)
• Georgi Stanev (SAP)
• Steve Powell (SpringSource/VMware) (who wrote the journal)
• Krasimir Semerdzhiev (SAP)
• Dmitry Sklyut (Chariot Solutions)
• Florian Waibel (EclipseSource)

Presentations

• Agenda, SpringSource roadmap, lists of topics to cover
• SAP roadmap, slides covering topics raised
• Notes on some Virgo repositories
• Web layer and Jetty

The Future?

Thanks to xkcd.

Minutes

Tuesday 30 November

Set objectives of F2F:

• Discuss work items
• Agree roadmap for 2011
• Discuss how we will work together
• Prepare new committers

Discussed use cases:

• application development with IDE and associated Virgo runtime
• server platform with clustering and "sandbox" support for potentially misbehaving applications
• embedded as a thin layer in other products
• kernel with custom extensions, not necessarily including web support
• migration of existing WAR files etc: ORM should just work, when split into bundles should continue to work

High level requirements:

• an application working in development must continue to work in production, e.g. wiring should be predictable
• clear rules for what constitutes an application comprising multiple bundles

Kernel discussion:

• Migration of user region from nested framework to framework hooks
  • Migration to Equinox 3.7 complete
  • Prototyping necessary to see how well the user region functions with framework hooks
  • May need to feed back issues into OSGi spec work, so needs to be high priority

• File system layout
  • Several benefits to adopting standard Eclipse/p2 layout
  • Issues: clustering/sharing, cold start, tooling, additional folders (work, serviceability, ...)

• Startup order
  • There is no waiting for configuration so it is not possible to loosen up the current startup order
  • This is supported in Spring DM v2 which can be used when Virgo rebases on Blueprint instead of Spring DM 1.2.1.
  • Namespace support also implies an ordering.

• Declarative services:
  • Should be supported "out of the box" by Virgo
  • There may be benefits for Virgo exploiting DS for its own service wiring, at least for the kernel - prototyping necessary

• Deployer extensibility:
  • Today this requires adding a fragment to the deployer bundle
  • Requirement to extend the deployer using public APIs only
  • Proposal to introduce a descriptor/facade which would clarify the extension contract

Build & release discussion:

• There is now no dependence on publishing to Amazon S3 and this can be ripped out fairly easily
• This will enable new committers to ripple and release without needing SpringSource S3 keys
• Requirement to do developer/local ripples without publishing built artifacts
• Requirement to produce a p2 repository from the build
• Maven repo can now be published to build.eclipse.org
• Discussion about Tycho and difficulty of managing manifests outside the IDE

Repository & p2 discussion:

• Overview of existing Virgo artifact repository
• Overview of p2
• Staged approach discussed:
  • Use p2 for initial provisioning of Virgo - may pre-req file system layout change
  • Add p2 to the Virgo repository chain - needs e.g. p2 touchpoint for plans, PARs, etc.
  • Drive deployment/update via p2
  • Drive deployment via kernel and keep p2 profile and bundles.info updated

Wednesday 1 December

Reviewed minutes from Tuesday and completed p2 discussion.

Discussion of Virgo's advantages and disadvantages relative to Aries, Glassfish, & JBoss.

Discussion of development and production modes.

• Important that any such mode is emphasised in the admin console.
• In production, SAP disable JSP compilation, disable pickup/dropins, disable JMX, ensure console can only be accessed from localhost.
• In development, SAP increase detail in HTTP access logs.
• General discussion of the need for making persistent configuration changes from the admin console.
• There was a consensus that a mode is desirable with a default of "development".

Discussion of "precompiling" dependencies and deploying preferred/mandatory wirings with an application.

Discussion of state of play of Jetty support and snaps.

• Snaps could be improved so that a snap specifies its host web context path instead of bundle symbolic name and bundle version.
• Discussion of a snaps subproject. Glyn will look into the overhead of creating a snap subproject.

Discussion of Tomcat and Gemini Web.

• There is a need for Gemini Web documentation.
• Tomcat 7 is expected to ship by 1Q11, so Virgo can migrate to Tomcat 7 for the next release.

Discussion of enterprise features and the desirability or not of Virgo supporting the Java EE 6 web profile.

• Consensus that web profile support would be a good thing.
• There is a need for representative system tests for JPA etc. usage to ensure these scenarios continue to work.

Discussion of roadmap - see the presentations from SpringSource and SAP.

General discussion of the responsibilities of committers in terms of:

• community support, coding, and testing.
• Florian ran through the "RAP House Rules" new committers presentation.
• In addition to the books already recommended for committers on the wiki, Dmitry recommended Richard Hall's "OSGi in Action".

Discussion of admin console and shell support.

• Likely that Apache gogo will be supported in Equinox.
• Desirability of command history, tab completion of commands and parameters (names *and* values), and ssh support was discussed.

The meeting finished a little early as we were well ahead of schedule.

Thursday 2 December

Eclipse RT Packaging (RTP) project

• Florian led an exercise where we installed Jetty, Equinox, or Virgo to get a feel for how difficult this is for newcomers.
• The objective of RTP is to simplify the initial experience of installing RT projects.
• Discussion of mixing and matching features prior to download.
• RTP is not currently envisaged as containing much code, so there was some discussion of whether this was realistic.
• Krassi agreed to be available to talk to the RTP committers about requirements and to offer assistance if appropriate.

New committers.

• Committers elections are underway for Violeta (also proposed for Gemini Web committer), Borislav, Hristo, and Dmitry.
• Florian is interested too and needs to increase his track record of contributions before we can propose him.
• Shared skype contacts to ensure good communications between committers.

Discussed Virgo tooling and OSGi Enterprise Tooling.

• Discussed whether it will be possible to use the OSGi Enterprise Tooling out of the box with Virgo or whether this would show some kind of vendor bias.

Overview of web admin console and brief discussion of dojo and Spring MVC usage.

Discussion of shells

• What we get for free in Equinox 3.7 such as class loading and Declarative Services commands
• The likelihood of Apache gogo becoming available, with pro's and con's TBD.

We revisited the roadmap discussion.

• No changes were needed as we are pretty much aligned in what needs to happen.
• There is a need to make Virgo startup much faster. SAP are interested in analysing this and Glyn is happy to help process the findings and consider trade-offs relative to function.

Brainstorming of Virgo futures and committer working methods - see the mindmaps.

git branching model

• Dmitry point out this article on git branching http://nvie.com/posts/a-successful-git-branching-model/.
• We discussed branching approaches, but for now we will continue branching off master for features and merging back into master rather than collecting on a separate development branch.

Kernel development

• We looked at how to make a code change and ripple it up, although the ripple failed with a hang in the web layer which appears to be an intermitted problem possibly related to machine settings such as VM heap/permgen.
• Glyn gave a brief tour round the kernel and explained the high level design of the deployer.
• Dmitry proposed a refactoring to loosen coupling in the deployer which he will prototype.

We then broke into separate groups.

• Code review of inner framework supportability contribution.
• Discussion of resolution strategies and p2 interaction with the deployer.
• Pair programming to publish p2 artefacts from Virgo build.

Finally, we agreed that we should reconvene before June 2011 but we would see how the next few weeks go before deciding on a precise date. SAP are happy to host in Sofia.

Logistics

Dates

30 November to 2 December (this was 1 Dec, but we had enough to fill an extra day) 2010

Venue

The meeting was held in Meeting Room 2 on the First Floor of Kenneth Dibben House, Enterprise Road, Chilworth, Southampton, SO16 7NS, UK. Kenneth Dibben House forms part of the University of Southampton Science Park. Enter Kenneth Dibben House, go up the stairs and the meeting rooms are on the landing. To enter the SpringSource offices, take the corridor labelled "South" and we are behind the first door on the left.

Accommodation

Chilworth Manor Hotel is located on the Science Park and is less than 5 minutes walk from Kenneth Dibben House. If you would like to stay at the Manor, please telephone the hotel on +44 2380 767333. The cost is around £80 per night. [The weather was atrocious, so even the 5-minute walk was a little daunting!]

Other hotels include: -

Hilton Southampton, Bracken Place, Southampton, SO16 3RB c. £120 per night; 2 miles from meeting venue

Holiday Inn Eastleigh, Leigh Road, Eastleigh, SO50 9PG c. £120 per night; 4 miles from meeting venue

Premier Travel Inn Southampton Airport, Mitchell Way, Southampton, SO18 2XU c. £65 per night; 4.5 miles from meeting venue

Jurys Inn, Charlotte Place, Southampton, SO14 0TB c. £110 per night; 5 miles from meeting venue

Holiday Inn Express Southampton M27, Botley Road, West End, Southampton, SO30 3XA c. £65 per night; 7 miles from meeting venue

Flights

Southampton Airport (SOU) is 5 miles from the Science Park and services short-haul European destinations including Paris, Amsterdam, and Frankfurt.

If you can’t fly to Southampton, choose a flight that takes you to London Heathrow (LHR) or London Gatwick (LGW).

Transfers

If you’re travelling into Southampton Airport: - Checker Cars operates from within the Arrivals Hall. You can pre-book a taxi from here to your hotel by calling +44 2380 627100. Give the taxi company your incoming flight details so they can keep themselves informed in case your flight is delayed. When you arrive, make yourself known to a member of staff on the Checker Cars booth. A taxi journey from Southampton Airport to any of the hotels listed above should cost no more than £20.

If you’re travelling into Heathrow or Gatwick: - You can pre-book your journey by contacting Rainbow Cars (rainbowph@btconnect.com) on +44-1794-514055 (mobile/cell +44-7850 722807). They charge around £85 for a one-way transfer between London Heathrow and Southampton.