All posts by Wei-Chiu

Wei-Chiu is a PhD candidate at Purdue University. He's interested in enabling elastic computing in cloud infrastructures. When he is not writing code, he spends most of time reading Wikipedia articles.

Programming Model Support for Dependable, Elastic Cloud Applications

Here’s an introduction to our HotDep’12 paper

While the word ‘cloud-computing’ has become a cliché, the real strength of cloud is not yet undermined.

Elasticity, the ability to scale up or scale down the application on demand, is not understood clearly to date. There are a few exception though, such as MapReduce or bag-of-tasks type of applications. However, These programming paradigms are  simple, usually stateless, and therefore easy to perform dynamic provisioning and so on. For more general type of applications, there has been very little research on how to enable elasticity to them.

We propose a programming model which enables elasticity. Moreover, it makes the programmer easy to reason about the execution of the application in elastic environment. In the model, an application runs in a “logical node.” A logical node is composed of multiple “physical nodes.” Regardless of the number of physical nodes involves in a logical node, an event executed in a logical node is logically equivalent.

However, elasticity induces a new fault-tolerance issue. A naive elasticity scheme would increase failure rate by allowing a physical node failure to induce the entire logical node failure.

Interesting, we found the mechanisms of the programming model naturally provides a solution to the fault-tolerance problem. Specifically, our programming model can recover failures at per-physical-node basis, and thereby transparently masks the physical node failures. More details of the programming model and the failure tolerance mechanisms can be found in the paper.

Our Hotdep12 Paper

OSDI’12 Poster Accepted!

My poster “ContextJob: Elastic Cloud Application Runtime” is accepted at OSDI’12 conference! In addition, my student travel grant to OSDI’12 is also awarded.

OSDI’12 is one of the top conferences in the computer system design and implementation area. I will be attending OSDI conference during October 8th~10th, and HotDep’12 workshop co-located with OSDI on October 7th.

500th commit in Mace-Fullcontext!

Congratulations to all of the contributors: Bo, Sunghwan, Rui, Yu-Chen, Chip and Milind. I almost forgot to mention that our 500th commit of Mace-Fullcontext has been pushed up to the repository! I would like to thank all of you who have contributed to this project.
We officially committed the first changeset on last December 21, and it took less than 9 months to reach the 500th. Since that time, we have committed more than 22,000 lines of code into repository.
The mace fullcontext project is a follow-up project of Mace-incontext, a parallel execution event driven system, led by Sunghwan Yoo, and we started the discussion since about last October. So it’s been almost a year ago!

Another New Semester!

Hooray! Another new semester is here, and it’s my 1,2,3…. anyway, I’m not going to count how many semesters I’ve been here.

Yesterday midnight, I finally got my summer assignment done just before the new semester commences…. Well, sort of, I demonstrated it was working in some cases, and I still need to tighten up some loose ends before concluding this work and submitting it to the conference, but at least I showed it’s a working idea!

Work, work, work and more work! I’m full of energy now!

慢跑

我很喜歡慢跑。不過從小時候一直到當兵以前我其實都不太習慣運動。一直到進了海軍在某艦上服役才改變。在船上的日子是相當悶的,就算靠岸的時候大部份時間也只能困在那牢籠般地鐵殼裡。就因為如此,我變得非常珍惜每次靠岸的傍晚,只要艦上海軍口笛一吹收工,我就一定要沿著軍港繞跑一圈。

回到主題,慢跑。我特別喜歡慢跑快結束時不顧一切全力衝刺的感覺。在那個當下,雖然上氣不接下氣,腦袋卻特別清楚:當喘一口氣、吸一口氣都那麼艱難的時候,突然就了解人的生命是多麼珍貴。如果有人問:人生的意義是什麼,我會回答:人生其實只有一個意義,就是盡可能的吸進下一口氣,再吐出那口氣。

我不是在開玩笑。這雖然聽起來很蠢、很簡單,但有些時候人會想太多,然後就想不開…

小時候覺得成功就是要考第一名、做大事賺大錢,長越大心願卻越小,現在只要每天吃得好睡得飽、排洩順暢就很成功了。也許再過幾年我就會覺得只要每天吸得到空氣,不要斷氣,人生就是成功了吧。