Back in NC!

Long time no post….  Now I’m just here to check in and make sure the site’s still working.  :-). Well, and to say that I’ve moved to Google’s new Durham office, where I’ll keep working on the same networking problems as before.   It’s good to be back in my home state, were the kids can hang out with family.

MaceKen: USENIX ATC 2012

I learned this morning that our submission to the 2012 USENIX Annual Technical Conference (ATC) has been accepted for publication. As with other paper announcements on this blog, I am merely sharing the good news, and forward-referencing an eventual post describing the paper at our research group website ( Briefly, the paper is about supporting a new failure model for programming large scale distributed systems, allowing those systems to ignore crash-restart failures using our otherwise pre-existing Mace programming model. Sunghwan Yoo is the main student author on the paper, and it is done in collaboration with Terence Kelly at HP Labs, Hyoun Kyu Cho—a prior intern of his, and Steve Plite—of the IT staff of the CS department at Purdue.

Recent Security Papers

So in research progress, we’ve recently published or had accepted two conference papers in the area of distributed system security. The first is a paper called “Removing the Blinders”, with co-authors David Zage and Cristina Nita-Rotaru. The basic insight of the paper is that in many protocols, nodes make decisions about other nodes based on just the last message they got from them. This is a kind of “blinders”, hiding other information the node has about the other nodes, which prevents them from making smart decisions about the peers based on the holistic information available.

However, the effort required in the first paper is totally manual. Discovering the set of attacks, and then finding the defenses for those attacks is takes a smart person thinking about it for a long time. We next set out to solve part of the problem – discovering the attacks. We focused on a restricted set of systems—those implemented in a structured language such as Mace. By applying a greedy state space exploration search strategy, we can discover a class of attacks that cause poor performance in systems. This work was accepted to NDSS 2012, about a tool we call Gatling.

Meanwhile, part of our current research involves further generalizing this work.

Virgin Mobile MiFi is Useless

Before Christmas, I purchased a Virgin Mobile MiFi as an alternative to the then-weak tethering options for an iPhone. I was particularly excited about the MiFi from VM because I do not need one all the time, but just sometimes while I’m traveling.

Over Christmas, it worked OK. I had a problem keeping it charged in the car because it wouldn’t charge from a normal micro-USB connection, but needed a specialized one (I think it may simply have to do with making the data lines, but for whatever reason it would not charge from a separate USB cable plugged into a car-USB adaptor, despite the fact that it will charge an iPhone and an iPad simultaneously.

But I fixed that by getting a separate car charger. Well, now I cannot download any content at all over the MiFi. It became un-activated, and I had to go back through the activation process. After doing so, I can download content from (I even purchased some bandwidth so I could use it – I’ve been able to use none).

I’ve now tried to use the MiFi 3 times on 3 separate days over 3 weeks. It has failed each time, with the same symptoms. I have rebooted everything, tried to use the reset button on the device, the laptop, etc. I am thoroughly and utterly convinced that it is a VirginMobile problem. (This is obvious from the fact that it can connect to the virgin mobile site).

I also tried to call the support line just now, and sat on hold 5 minutes with frequent apologies from the automated system that they are busier than usual. From what I’m reading on websites, they have been busier than usual for months.

So that’s it. I’m going to give up on my MiFi. I might try to sell it, except that I don’t think I would feel good selling it.

Instead, I’m going to try the new hotspot functionality of my iPhone. It’s disgustingly priced as a tethering plan, but from what I’m reading, I can turn it on and off at will, switching between data plans anytime I want. So if that’s true that may work out well for me.

If VirginMobile wishes to correct this, they can refund my $20 for the data I bought recently, and contact me. Maybe they can unlock the device to use with companies other than VM, or maybe they can make it work. But from what I’m reading on the internet, this infrastructure is just a disaster, and many of us feel like we totally wasted the money we put into it.

Oh well. Live and learn.

Upcoming posts…

So I need to add some posts. I don’t have time to write them now, but if I promise them here, maybe I’ll make the time for it.

  • More games – pandemic, ticket to ride, etc.
  • iPad review
  • Research report – FSE paper

BTW, did I mention I now have a son?
He’s doing well – now 5.5 mos old. Now I’ve finally recovered some and am digging out of the hole a bit, hence the new posts.

Entering the Hi-Res Age

Happy Halloween!

This week, Kristina and I splurged, and bought one of the new 27″ iMacs. Why? Not because we needed a computer — our laptops are sufficing just fine. No, we bought the 27″ iMac to replace our 6-year-old 27″ [analog] Television. This post will serve as my review of our impressions of using this as our main video-viewing-portal thus far.

The short version? We’re impressed. Sure, there are problems, and some we can fix (getting a remote control), where some we can’t really fix (Apple keeps using a high-gloss screen, which unfortunately makes for a nice glare).

Before being able to understand this review, however, I should let you know a bit about our viewing preferences, needs, etc. I have previously posted about hos we were considering canceling our cable TV. Well, we have decided to cut back to just the primitive broadcast cable channels, but haven’t made the call yet. What we don’t need is:

  • Something to watch sporting events. We just don’t watch sporting events.
  • Something to watch Blu-Ray discs. We don’t have any, nor a blu-ray player, and don’t see this as a priority going forward.
  • Something to watch live broadcast, analog cable, or HD cable TV on. We don’t have a cable box, and don’t want one. We haven’t watched any noticeable amount of live TV in years.
  • A huge TV which seems to be so popular today. We’ve always been quite content with our 27″ TV, and were not in the market to make the TV a bigger part of our den.

So, what we do want in our video-viewing-portal is this:

  • MythTV (just the frontend). This is how we watch most of our recorded TV, through our analog MythTV backend. We previously had Mini-ITX-based MythTV frontends attached to each of our TVs. This has been great, being able to access our DVR from any TV, and use the MythTV mechanisms for commercial skipping. However, since thinking about how few channels we actually watch vs. how much we pay monthly for cable TV, I’ve been looking for another legal way to get the TV content we do want to watch.
  • The ability to play content from Hulu and Netflix. What we have discovered is that the vast majority of content we care about is available from these two sources. Unfortunately, the mini-ITX boxes (and even our more powerful MythTV backend) were jerky and unable to handle the flash video CPU requirements of Hulu, and since they were running Linux, there was not option to view Netflix instant watch content.
  • The ability to watch DVDs. DVDs are our primary mechanism for having stored and mailed movies, so we needed to be able to continue this.
  • The ability to control the video-portal in an easy, straight-forward manner. Ever since we added StreamZap remotes to our MythFrontend boxes, we’ve been able to watch MythTV in an easy manner. Previously, we had a wireless keyboard, but it was big and bulky, so the remote was a HUGE step up.

So, how does the iMac stack up?

  • Size. With a diagonal of 27″, it has the same diagonal our prior TV had. Granted, it’s a widescreen (16:9) format rather than the traditional (4:3). So it’s a little wider, and a little shorter, than our older TV. One problem with the huge number of pixes though is that all the OSX fonts are super-tiny when sitting on the sofa. Sure, you can do screen zooming to see it, but it’s really annoying to have to do that all the time. Plus, there’s no good way to increase these fonts. A LOT of applications suffer from this problem, and the menu bar always suffers it.
  • Quality. The image quality of the iMac is GREAT! The glare on the screen is annoying, but it’s not significantly worse than our prior TV. Video quality is excellent. The screen is plenty bright, and can easily be seen from the sofa, or even the kitchen while making dinner. We don’t even turn the brightness of the screen all the way up usually.
  • DVDs. DVDs play without trouble, however, the DVD is loaded into the side of the iMac, which is a problem since our entertainment center (in which it fits) is too close to the side of it to allow loading the DVD. So we have to angle the iMac to load the DVD, which is at least better since it’s not that heavy
  • Hulu. Hulu plays just fine, on everything we have tested thus far. And thanks to the OSX release of HuluDesktop, we can even browse/view Hulu content without having to use the web-browser, which was hard due to the size mentioned above, means it can be navigated with just the keyboard. Further, a plugin to FrontRow allows HuluDesktop to be launched from FrontRow, so you can easily launch it from the keyboard as well. As an added bonus, the video quality is higher than that of analog TV. Granted, the downside of Hulu wrt MythTV is that we have to watch commercials again, but at least they are usually short, and you at least know how long they are.
  • NetFlix. NetFlix instant watch works great on the iMac. The only initial problem was again that we had to use the web browser. But I then realized that Boxee can be paired with your NetFlix account, and then be watched flawlessly with simple, large-font navigation. The navigation works better even than browsing content on the NetFlix site, IMO. Another FrontRow plugin allows Boxee to be launched from FrontRow, making that easy too. Big plus for NetFlix: no commercials.
  • MythTV. This also works fine, and can be launched from FrontRow. The content is lower quality, but doesn’t require the internet, and allows skipping commercials.

Okay, so what does this leave? A big deal has been made of the iMac because it can be a video input [monitor] as well as video output. Unfortunately for most, it only accepts displayport signals, and a simple cable adapter does not work to allow e.g. BluRay input. Not a problem for us, and it means that in the future it can serve as a nice monitor for one of our computers. Another problem is the remote issue. The included bluetooth keyboard is reasonably small, so it’s not too bad. However, we plan to purchase an Apple Remote for use here. Unfortunately, the StreamZap USB remote we already have (which has many more buttons and would be more ideal), cannot be used because it isn’t supported under OSX. Other minor issues – it wakes up from sleep sometimes for no good reason, and you cannot just turn off the keyboard after putting it to sleep (the iMac wakes itself back up).

So, we’re pretty happy overall. I think more and more content will be available for download, so our bet is that this is a better solution for us than joining the traditional big-screen high-definition TV-purchasing crowd. The iMac was a good buy, and with a 3-year AppleCare protection plan we can have peace of mind about the machine’s reliability as well. Extra added features – it’s iTunes player will surpass the MythTV music player in quality and ease of use. Other possible uses — it has an iSight camera which could be used for living room video chat, and picture browsing for family-room slide shows. Boxee comes with a number of other video input sources available.


I had the fortune of being upgraded to first class in my flights from Seattle back to Indianapolis yesterday. In Minneapolis, I got in line to board the plane after the announcement of first class seating, and was second in line, when I hear the gate agent ask someone behind me if they are in first class.

Immediately upon hearing the question, I cringe. I hope, hope, that the person behind me is looking lost and is in fact not in first class, to avoid the significant potential for a train wreck right there in line. The response from behind me is [imagine being said with a slight amount of attitude] “Of course I’m in first class. Why would I be in the first class line if I weren’t in first class!”. Uh oh. The gate agent just stepped in it, and in a big way. Thankfully, the African-American woman behind me leaves it at that. As we walk down the gangway, I hear the woman describe what just happened on the phone, while letting the person on the phone know that she didn’t make a scene. At this point, very amused, and thankful that the boarding process was not going to be delayed today, I turn around and let the woman know that I was very proud of her for keeping her cool. Tiffany ends up being seated next to me, and on further discussion about it, she lets me know that today, she is in a really good mood, and she wasn’t going to let that bring her down.

So let this be a word of warning. Don’t assume. What I expect the gate agent should have done was to first check her ticket, and then remind her she was in the wrong place only once he was sure her ticket was not a first class ticket.

Summer is here

So as a graduate student, I really didn’t understand the full extent of summer. Because I was not involved in classes the last several years, I had no idea how much better research productivity could be during the summer. I have had to deal somewhat with the students who didn’t get the grade in the class and want to re-examine that, but overall it’s great. I’ve heard many faculty this summer express a similar sentiment.

So to all – have a great summer! I fear it may be over far too soon.

New Blog Picture

At NSDI, which I recently returned home from, no fewer than two people exclaimed to me that I did not look at all like they expected. On talking to them about it, I’ve found that they were using my picture from my website/blog as a picture of me. (This is fair, since I did put it there.) The problem is I put it there 7 years ago and haven’t changed it. I’ve changed a bit in appearance since then. So I’ve updated the picture on my site/blog. For comparison’s sake, you can see both here:

Engagement PicturePurdue Studio Picture

It is finished.

I have defended my dissertation, and filed it with the University. It’s formatting has been approved by the appropriate people, and the Dean of Graduate Studies has approved my final paperwork. I believe that officially, I have now completed my Ph.D. Graduation is June 22nd, and my parents, in-laws, and brother-in-law (and of course Kristina) will all be in attendance as my advisor hoods me.

Now it is time for a few brief moments of relaxation and a vacation, then it’s time to move on and get started on my career.