Byzantine Reality

Searching for Byzantine failures in the world around us

CloudComp 2010 Field Report

This week I am at CloudComp 2010 in Barcelona, Spain to present our group’s recent paper on Active Cloud DB. So I figured that while I was here, I had might as well report on the keynote talks given as well as the best of the papers presented there. Enjoy!

Keynote Talk One

Ignacio Llorente, project lead over at OpenNebula, gave the first talk of the conference, discussing the various features that the OpenNebula cloud infrastructure offers its users. One of the more interesting features he discussed involved hybrid cloud support – specifically, OpenNebula can act as a broker between clouds, providing a single, unified interface between any number of private clouds you may happen to have and public clouds. Unfortunately, he didn’t get into many technical details and really just listed all of OpenNebula’s features, which I guess is ok since it was a keynote talk, but for an hour long keynote I was expecting any kind of depth and not just breadth.

Top Paper from Day One

Alexander Reinefeld gave an interesting talk named Data Management in Clouds, which (1) is a really generic paper title and inevitably (2) IMHO was quite a bit of a misnomer, since it was really about XtreemFS, a file system targeted at the grid computing world. He said we needed a cloud file system, but didn’t really make the case that this was “cloudy” in any way – there didn’t seem to be any discussions about elasticity or anything else we seem to hear about in the cloud world. Otherwise the talk seemed pretty solid – it doesn’t really seem to be a research project as much as being a production-level-ish piece of software.

Keynote Talk Two

Alvaro Arenas gave the second day’s keynote talk, discussing the XtreemOS project. He went for the opposite approach of the previous keynote speaker – lots of depth on one part of XtreemOS (the security layer) and very little on the rest of the system. Unfortunately, it didn’t seem to be really talking about cloud computing at all – the project is firmly rooted in the grid computing world and doesn’t really talk about challenges or benefits in the cloud world. Specifically, I was looking for him to say anything about how an operating system works when the number of nodes in the system changes (a common cloud use case) or anything about SLAs (also extremely common to the cloud) but didn’t hear anything about either.

Top Paper from Day Two

(Asides from my paper, which was also on day two, of course!)

Guillaume Pierre talked about CloudTPS, their way to get ACID-transactions in NoSQL databases. It basically puts a transaction manager in the system which handles this on behalf of the database. Of course, this component is distributed (many nodes) and implements the well-known two-phase commit protocol. The presentation was very interesting but there were a few things I would have liked to seen that weren’t there:

  • How the evaluation is performed was a bit vague – he was a bit low on time at this point and would have liked any explanation of the graphs more than “yay it scaled!”
  • We sharply disagreed on what “consistency” was – they claim that Amazon SimpleDB was eventually consistent even with consistent reads and that NoSQL datastores favor availability over consistency – which just isn’t so (see HBase, Cassandra with consistent reads/writes, MemcacheDB, and so on). After a bit of discussion I believe he was trying to say that consistency to him meant ACID – but clearly it is not the case that these datastores favor availability over consistency just because they don’t have ACID transactions.

Regardless the talk was very interesting and the general idea was sound.

Keynote Talk Three

Kate Keahey, project lead at the Nimbus Project, gave the last keynote of the conference, about the pros and cons of using cloud computing for running scientific experiments. She gave a breakdown of how Nimbus is implemented as well as the tools out there that sit on top of it.

I found her talk to be the most straightforward and the best talk of the conference (again, outside of mine of course). I liked her approach of talking in some depth about many topics to be far preferable to the other keynotes’ styles of no depth and all breadth (keynote 1) or all depth and no breadth (keynote 2).

She also talked about how Nimbus is used in real science, with a number of cool use cases and a good but brief discussion of how they run their open-source world. It was fairly simple – a few core committers on the project and a few more on github, but since it usually isn’t talked about too much in these settings, I found it to be insightful.

Top Paper from Day Three

Burkhard Neidecker-Lutz, one of the conference’s program chairs, stepped in and gave a talk on a paper that the authors were unable to present themselves, on a framework for information and billing in the cloud. I found this paper to be unique not because of the actual paper itself – the slides in fact were blobs of text and somewhat inpenetrable, but what was interesting was how Burkhard was able to take a different group’s paper and not-so-great slides and really turn it around. He was able to use examples from other papers seen at the conference to really save that paper and make for a very interesting discussion, at the least. So my thanks go out to him to show that it can be done – others who took up presenting papers that weren’t theirs just read it real fast and ran for the hills, so this was good proof that it can be done the right way.

Wrapping Things Up

Unfortunately I couldn’t find a list of the papers online anywhere, but it looks like most of the papers can be found via our friend the Google. While mulling things over at the conference and in this hotel room, I also have a number of new interesting cloudy ideas, so stay tuned!