Blast from the past

I had no idea the University was scanning in old theses. I haven't seen this one for almost 20 years!

Cloud and multitenancy

Over the past year or so I've been doing a lot of thinking about various aspects of cloud. One of the ones I keep coming back to is the issue of multi-tenancy. Many years ago, when I was formulating the categorization of transactional replication strategies, we found that splitting up the object server (methods) from the state and allowing each to be replicated independently, gave the ability to express everything necessary to cover the range of replica consistency protocols from passive through active. Sharing of the executable versus sharing of the state is based on aspects such as determinism of execution (passive is the only option in some cases) and speed of fail-over (active tends to do much better).

So what has this to do with multitenancy? Well I've been thinking about what it means to have a true multitenant application and hence PaaS. Some people seem to suggest that multitenancy is somehow new, complex or the domain of a new breed of engineers and vendors. But if you think about it, we've been using multitenant environments for years. Your operating system is multitenant, with multiple applications resident and often running concurrently, perhaps modifying shared data structures as a result. Even your modest Web server can be considered multitenant. And there are a range of strategies for achieving multitenancy based on a similar server/state split. Therefore, whether you're a SaaS implementer or a PaaS architect, the same factors come into play. And critically for SaaS implementers, if your PaaS doesn't support these things then you're going to have to!

In terms of PaaS, there are really 3 components that can be played with in terms of multitenancy and application and data deployment. These are the VM, the application server (container of business logic) and the data (database, file system etc.) For instance, you could have each tenant in a separate application server but running on the same VM, with data split between different database instances. Or you could have each tenant in the same application server on the same VM, with data in the same database, perhaps split on different tables. (Other options and configurations exist, of course.)

Now all of these various combinations have more or less been around before, as I said earlier. The big problem though has been around ease of use. I've written enough Unix kernel services before, for instance, to know most of the ins-and-outs of sharing state without causing the operating system to crash, and the best way to use pthreads or memory mapped files in a shared environment, but it's not always intuitive or based on well documented processes. This is precisely where a PaaS fits in: it must support the widest range of approaches and in a way that does not require the SaaS developer to have to worry about them. We can learn a lot from what's been done in the past around the intricacies of achieving multitenancy, but we do need to make it far more consumable than has perhaps been the case so far.

Interesting new paper on transactions

I met Daniel Abadi at HPTS 2009 last year, where he presented on HadoopDB. Very interesting and a good presenter. So it's good to see his latest paper on determinism and transactions in database systems. It's a good read and particularly for me because it mixes the two areas that have always been my interests: transactions and replication. The authors have some good things to say about NoSQL, but specifically around relaxing ACID semantics, the trade-offs that incurs and how perhaps there is an alternative. Again, this is an area I've had a bit to do with over the past few decades. I'll have to think about how and whether this is applicable to some of the work we're doing at the moment in large scale data grids.

Coming of age?

Thousands of years ago the coming of age ritual involved hunting and killing (e.g., mammoths or dinosaurs, depending upon which film you believe). Due to changes in a range of things, including society and the fact that mammoths (as well as dinosaurs) died out (maybe related to hunting, strangely enough) the rite of passage changed.

In our household one aspect of our version of this ritual is introducing the kids (my 8 year old now) to the all time great movies. Several weeks ago it was Lord of the Rings, which went down really well. This weekend we started into Star Wars. Of course the first question was which order to play them? Against my better judgement we went with the chronological order, i.e., Episode 1 first. The first two movies went down well with him, though the third was more of a slog, but of course the best movies are yet to come.

However, I realised that although it's been about 8 years since I've watched the movies, two things remain a constant for me: the midichlorian rubbish detracts from the story (what was George Lucas thinking?!) and I still can't stand Ja Ja Binks! But my son loved him! If he loves the Ewoks then all is lost and I think I'll fail him on this rite of passage!

Long weekend coming up

It's a national holiday here on Monday, so this is a nice long weekend. Unlike my 2 week vacation which only ended at the start of last week, I've decided to not touch anything remotely work related until Tuesday (that holiday turned out to be > 50% work!) Well that's the theory at least. I know there may be some pressure to bend that rule slightly, so we'll wait and see!

CloudBees

It's been 18 months since Sacha left JBoss and I took over. He said he was going to take time off to enjoy being with his family and (then) new baby daughter. However, I think many of us knew that at the time it wouldn't be long before he was back doing something interested. So it's really good to be able to announce that that effort is called CloudBees and they've officially launched! Hudson as a Service (HaaS) is a really good idea! Coincidentally it's something that JBoss and Arjuna separately considered at one time or another with their/our Distributed Test Framework.

Good luck Sacha and team!

BBC Micro making a comeback?

I loved this article! It brought back a lot of memories from when I was programming in BBC Basic. I upgraded my machine to support Metacomco's Pascal and C as well. Lots of fun and I like to think the "hardships" that the students of today mentioned helped to make me appreciate what it takes to write code in less than 32K of memory!

Classic C++ textbook

Every now and again I have to go through my cache of books and box some of them up for storage. This time it was some of my old text books from university, but while going through the process I went through all of my C++ related books. One of the best I've ever read is Barton and Nackman. I got this book just after it came out (I think I got it just after visiting Graeme at Transarc.) It's a wonderful book and reading the Amazon comments afterwards it's good to see that I'm not alone in thinking that. If you're a C++ programmer then you should definitely check it out.

Private Clouds?

I've known Werner Vogels for several decades, ever since we were both doing our PhDs. Like all good friends and scientists, we don't always agree on everything. Case in point is that Werner doesn't believe Private Clouds are clouds and I think his arguments against are artificial and short sighted. Now of course you could say that he and I take our perspectives on this debate precisely because of our employers. However, that's wrong, at least where I'm concerned.

As I said earlier this year, I think that today's definition of Cloud is limiting and emphasizes Public Cloud precisely because that's what most people have access to. But I also believe that Public Clouds are not going to be as important in the future. Cloud is a natural evolution of hardware and software (middleware) but if you liken the roadmap for Cloud to that of cars, today's Cloud's are like the Model T: showing everyone the potential, but not available to the masses. We should be looking at the equivalent of the next hundred years of evolution in automotive technologies as far as Cloud is concerned, bringing their benefits to the masses (of people and workloads).

This development has to include Private Clouds (which, contrary to what Werner states, don't necessitate corporations having to buy more hardware), but so much more. The true cloud is the collection of processors that exist virtually everywhere you turn, including mobile devices and sensors. That's where the definition of Cloud must go. In many ways it's returning Cloud to one of its progenitors, ubiquitous computing. By that point there won't be a Public, Private or Personal Cloud, there'll be "just" Cloud (or maybe some other term). Where your application is hosted will still remain important, but not because of any artificial reasons due to words such as 'private' or 'public'.

Why JeAS?

I've been saying for a while that the last thing the industry needs is a return the days of vendor lock-in or somehow resetting the clock on the past 40+ years of middleware and rediscovering it all again. That's why I believe we have to leverage what we've got. Yes, it needs to morph and evolve, but we should start using (reusing) existing investments. Furthermore, I believe that if the ideals behind Cloud are to be realised then they must start by tackling existing workloads.

This is why the application server (no formal definition in this article) is the right vehicle for applications. It doesn't matter whether you just consider this to be Tomcat or your favourite application server (JBoss, of course!), whatever is hosting your important applications today and which your developers are comfortable with, that's the basis of your own PaaS requirements. Therefore, that has to be the basis for PaaS wherever you may want to deploy in the future. But even today you often find that your application server may be providing more functionality than you need, at least initially. Just considering Java Enterprise Edition for a moment, that's one of the reasons behind the introduction of profiles (which always reminded me of the Core Services Framework Bluestone/HP pushed back in 2000, driven by my friend and co-author Jon Maron).

So this is where I come from when I mention Just Enough Application Server: when deploying into a PaaS you really need support from your underlying application server to ensure that just enough is deployed and no more. Ideally this should be done automatically as your appliance is generated, but static is OK too. Throw in a bit of autonomous monitoring and management in case things change on the fly (application and object migration is a distinct possibility, so the underlying infrastructure/application server needs to be able to cope), and you've got yourself one super sleek PaaS.

JeAS

First there was JeOS, which makes sense for IaaS. So what's the equivalent for PaaS? Well I reckon it's Just Enough Application Server (JeAS perhaps?) More on this subject soon!

JCP Award Nominations are open

Cross linking to the award notification.

Has Java reached a point of inflection?

I've been wondering about this for a while. As far as languages go, Java has experienced a good run, remaining in the number 1 or 2 spot for the better part of a decade. The language came along as the Web was really growing from its fairly basic roots as it's arguable that Java influenced the development of it more than many languages. It certainly took over from the likes of Pascal and C/C++ in universities and as a result most new software developers have more than a passing knowledge of the language. Of course it's never been a perfect language (I'm not sure such a thing will ever exist, except for very domain-specific languages); it's also never been my favourite language (C++ still holds that position.) However, I think that Java has had an overall positive affect on the industry.

The Java platform (formerly known as J2EE) took a few years to emerge after the first releases of Java (aka Oak) and initially competed with CORBA in the non-Microsoft camp. Once it was clear that J2EE would dominate, CORBA tried to embrace it more closely (the CORBA Component Model, for instance) but was never quite the force it once was. However, J2EE wasn't perfect and a lot of that could be traced to its CORBA roots. It wasn't really until EE5 and EE6 that it managed to escape those shackles, but even despite those problems it dominated the industry. Of course it's precisely because of some of these issues that frameworks such as Spring sprang (!) up, but even then a lot of those deployments ran on J2EE to simplify development.

During its life Sun was a pretty good custodian of the language and the platform. Yes there were issues, particularly when Sun moved from being a neutral party to one that competed in the vendor landscape. But when you think about how one other company in a similar position handled a similar position in the 80's and 90's, things could have been a lot less open. In fact I'm certain that the success of both the language and the platform is due in no small part to this relative openness that Sun managed to juggle, despite their conflicts of interest. Towards the end of their life as an independent company, with the likes of the Apache License issue, it was obvious that Sun couldn't quite make the necessary leap that was/is required to continue the dominance of the language/platform (and you could argue to revitalize it).

And of course that brings us to the present and Oracle. If Java was at a point of inflection prior to their acquisition of Sun, it continues to be there today many months afterwards. Myself and others have argued that this is a good opportunity for Oracle to "do the right thing" and make good on their previous statements in that regard. To continue without such change risks pushing us over that tipping point, with fragmentation, vendor specific options and the end of the world as we know it. (OK, that last point is unlikely to happen!) As I've been saying around Cloud, we really shouldn't be looking at turning back the clock: it won't do anyone, including Oracle, any good.

Now maybe Oracle are considering making some positive announcements at the forthcoming JavaOne. I hope so. Continuing to make Java open and fast moving will benefit everyone, customers and vendors alike. And hopefully Oracle can make the leap that Sun never seemed to be able to make. What's that they say about Nixon and China?

Red Hat/Newcastle University research day

Just back from the first official research day with Newcastle University and it was good. We covered a lot of short and long term research areas, including fault tolerance, scalability, event processing and policy definition/management. It all had a very heavy practical slant to it, which is event better given that we're hoping to see a lot of this come through into various JBoss/Red Hat projects and products eventually. All in all it was a good day and hopefully next time we'll take a couple of days so we can delve into things in much more detail. But for now I've got to go through my notes and start working on getting these R&D efforts underway!

JUDCon Europe 2010

I've mentioned JUDCon before, and it's only been a couple of weeks since we had the very first event in Boston, which went very well. However, no time to relax since it was always our intention to have a couple of these a year and it's surprising how much lead time you need to make it happen. So we've decided on the dates and location for the European event: 7th and 8th of October in Berlin. Next up is figuring out the themes for the tracks and then we'll open up the call for presentations.

Cloud-TM project

We're involved with a new EU Research project called Cloud-TM. Should be some good opportunities for long term research and development, whilst at the same time having strong industrial relevance. I'm looking forward to the kick-off meeting next week in Portugal!

DO'h!!

I've given countless presentations at many different events over the years and usually I'll either be on time or run slightly over time. On a few occasions I've finished early, but never have I finished 20 minutes early thinking that I was over time! I started my first JBoss World presentation this year at 10:20am and got into my stride. I think I got too caught up in what I was saying because at some point I looked down at my watch and noticed it was 10:50am. I obviously forgot what time I'd started because the only thought that ran through my mind was "Oh sh*t, where did the time go, I've only got 10 minutes left!" I managed to get through the remaining 10 slides or so by skipping some (fortunately they'll all be available on the web) and got into Q&A time, still blissfully unaware that I still had 20 minutes remaining. In fact it wasn't until I was walking away that someone pointed it out! So, if you were in that session I definitely apologise for rushing needlessly!

MW4SOC CFP

CALL FOR PAPERS
===============

+--------------------------------------------------------+
| 5th Middleware for Service-Oriented Computing (MW4SOC) |
| Workshop at the ACM/IFIP/USENIX Middleware Conference |
+--------------------------------------------------------+

Nov 29 Dec 3, 2010
Bangalore, India
http://www.dedisys.org/mw4soc10/

This workshop has its own ISBN and will be included in the ACM digital library.

Important Dates
===============
Paper submission: August 1, 2010
Author notification: September 15, 2010
Camera-ready copies: October 1, 2010
Workshop date: November 30, 2010

Call details
============
The initial visionary promise of Service Oriented Computing (SOC) was a world of cooperating services being loosely coupled to flexibly create dynamic business processes and agile applications that may span organisations and heterogeneous computing platforms but can nevertheless adapt quickly and autonomously to changes of requirements or context. Today, the influence of SOC goes far beyond the initial concepts of the original disciplines that spawned it. Many would argue that areas like business process modelling and management, Web2.0-style applications, data as a service, and even cloud computing emerge mainly due to the shift in paradigm towards SOC. Nevertheless, there is still a strong need to merge technology with an understanding of business processes and organizational structures.

While the immediate need of middleware support for SOC is evident, current approaches and solutions still fall short by primarily providing support for only the intra-enterprise aspect of SOC and do not sufficiently address issues such as service discovery, re-use, re-purpose, composition and aggregation support, service management, monitoring, and deployment and maintenance of large-scale heterogeneous infrastructures and applications. Moreover, quality properties (in particular dependability and security) need to be addressed not only by interfacing and communication standards, but also in terms of actual architectures, mechanisms, protocols, and algorithms. Challenges are the administrative heterogeneity, the loose coupling between coarse-grained operations and long-running interactions, high dynamicity, and the required flexibility during run-time. Recently, massive-scale and mobility were added to the challenges for Middleware for SOC.

These considerations also lead to the question to what extent service-orientation at the middleware layer itself is beneficial (or not). Recently emerging "Infrastructure as a Service" and "Platform as a Service" offerings, from providers like Amazon, Google, IBM, Microsoft, or from the open source community, support this trend towards cloud computing which provides corresponding services that can be purchased and consumed over the Internet. However, providing end-to-end properties and addressing cross-cutting concerns like dependability, security, and performance in cross-organizational SOC is a particular challenge and the limits and benefits thereof have still to be investigated.

The workshop consequently welcomes contributions on how specifically service oriented middleware can address the above challenges, to what extent it has to be service oriented by itself, and in particular how quality properties are supported.

Topics of interest
==================
* Architectures and platforms for Middleware for SOC.
* Core Middleware support for deployment, composition, and interaction.
* Integration of SLA (service level agreement) and/or technical policy support through middleware.
* Middleware support for service management, maintenance, monitoring, and control.
* Middleware support for integration of business functions and organizational structures into Service oriented Systems (SOS).
* Evaluation and experience reports of middleware for SOC and service oriented middleware.

Workshop co-chairs
===============
Karl M. Göschka (chair)
Schahram Dustdar
Frank Leymann
Helen Paik

Organizational chair
====================
Lorenz Froihofer, mw4soc@dedisys.org

Program committee
=================
Paul Brebner, NICTA (Australia)
Gianpaolo Cugola, Politecnico di Milano (Italy)
Walid Gaaloul, Institut Telecom (France)
Harald C. Gall, Universität Zürich (Switzerland)
Nikolaos Georgantas, INRIA (France)
Chirine Ghedira, Univ. of Lyon I (France)
Svein Hallsteinsen, SINTEF (Norway)
Yanbo Han, ICT Chinese Academy of Sciences (China)
Valérie Issarny, INRIA (France)
Mehdi Jazayeri, Università della Svizzera Italiana (Switzerland)
Bernd Krämer, University of Hagen (Germany)
Mark Little, JBoss (USA)
Heiko Ludwig, IBM Research (USA)
Hamid Reza Motahari Nezhad, HP Labs (USA)
Nanjangud C. Narendra, IBM Research (India)
Rui Oliveira, Universidade do Minho (Portugal)
Cesare Pautasso, Università della Svizzera Italiana (Switzerland)
Fernando Pedone, Università della Svizzera Italiana (Switzerland)
Jose Pereira, Universidade do Minho (Portugal)
Florian Rosenberg, Vienna University of Technology (Austria)
Giovanni Russello, Create-Net (Italy)
Regis Saint-Paul, CREATE-NET (Italy)
Dietmar Schreiner, Vienna University of Technology (Austria)
Bruno Schulze, National Lab for Scientific Computing (Brazil)
Francois Taiani, Lancaster University (UK)
Aad van Moorsel, University of Newcastle (UK)
Roman Vitenberg, University of Oslo (Norway)
Michael Zapf, Universität Kassel (Germany)
Liming Zhu, NICTA (Australia)

JBossWorld and JUDCon

Off to Boston tomorrow for JBossWorld and JUDCon. The former is always a good event, but it's really the latter that I'm looking forward to the most, since it's the first ever one and it's taken us a while to organize. I'm already working on the European version that'll be coming in a few months time so hope to get some constructive feedback from the people to attend in the coming few days. And for my long flight to Boston I'm having a complete break and finishing reviewing someone's PhD thesis.

Classic paper

I came across this paper in my pile of printed materials from when I was doing my PhD. Great paper at the time and still applicable today. Well worth a read.