All papers and the program can be found here: http://www.sosp2007.org/program.html

Listed here are my notes of the talks I found interesting:

Day 1

MashupOS - Microsoft Research

• Inline modules in HTML currently exhibit all-or-nothing behavior. They can either run with no interaction with the other components of the page (iframe) or run with the same privilege as that of the page (script).
• Introduce tags for allowing integration of unauthorized components from third-parties. This allows aandboxing external scripts running within a browser.
• Used for multiple-principle sites pooling in third-party principles and integarting as one.

AjaxScope - Microsoft Research

• For examining ajax execution remotely.
• Uses a ajax proxy between the server and the clients to insert the instrumentation to debug, test and optimize the ajax code.
• Injects javascript within the applications on the fly, to capture logs.
• Logs are sent back for inspection.
• No need to modify the client side code or browser.

Automatic Partitioning (Swift) - Cornell (Best Paper Award)

• Javascript-like programming language for auto-splitting client and server side code.
• Compiler decides which code should run where (client or server) based on security minimizing messages flow.
• Handles security and integrity using annotations.

TxLinux - UTAustin

• Transactional memory to be reality in Sun's new "Rock" processor.
• Locks are difficult to implement and use in the code. Makes code complex.
• Initial implementation to use transactions in Linux kernel. Not-so-easy to do due to legacy code and transactional-unfriendly code, especially involving I/O.
• Implemented co-operative transactions, which dynamically choose between spinlocks and transactions depending upon conflicts and I/Os.
• Easy to implement than complete lock to transaction conversion.
• Transactions are made scheduling aware to eliminate priority inversion completely.

MUVI - UIUC, MIT

• Variables are corelated, they relate to one or more variables.
• Idea is to leverage the relation of variables statically and identify possible bugs.
• Corelations are inferred by variable placement and distance between the usage of the variables.
• These corelations and the frequency of variables occurring in groups is calculated, which is used to detect if the developer has forgot to update or initialize a variable.
• Found real bugs in Mozilla.

Day 2

iComment - UIUC

• Comments in the code could get stale or incorrect over time. They are often used to specify assumptions made by the piece of the code.
• Idea is to leverage the developer's assumptions for verifying the correctness of the program.
• Uses NLP, statistics and data-mining to derive a set of frequently-used words for detailing certain things, like e.g. that a function should be called only with the locks held.
• Uses the decision tree to verify if other parts of the code ammend to the comments.
• Notifies for a possible bug in the code or invalid comments.
• No need to retrain or remake the decision tree across softwares since developers often use common words to siginify things. But can remake for less false-positives.

Sinfonia - HP Labs (Best Paper Award)

• Every distributed systems involves a complex message-passing protocol taking into account failures and concurrency issues.
• Idea is to have a framework which will deal with message passing and provide availability and concurrency guarantees.
• Sinfonia provides minitransactions as a primitive for building a data-centric message passing systems like cluster file systems.
• It takes care of load-balancing, fault-tolerence, coherency and scalability.

Dynamo - Amazon

• Amazon needs key-value storage solutions, it built it for themselves with 99.9% availability.
• It did not detail about how it measured 99.9% availability, but it uses distributed hash-tables with consistent hashing and versioning.

Integrating Concurrency Control and Energy Management in Device Drivers - Stanford

• A solution of efficient energy use in sensor networks. Implemented in TinyOS.
• Uses a power manager which drivers talk to for device-specific operations. The power manager handles the powering-off and powering-on of the device depending upon the requests.
• Amortizes the cost of powering-on and powering-off by trying to do it less frequently.
• Might as well be used for mobiles OSs and even generic OSs.

Day 3

DejaView - Columbia University

• Personal desktop experience recorder - fast and transaparent
• Virtual display driver to record the display on disk.
• Uses accessibility features of the OS and applications to record the keys and clicks, which also provide meta info about the text (application, menu text, focus)
• File system snapshotting for recording fs state.
• Allows browsing, replaying and restoring application states.
• Does not handle network connections.

I/O Shepherding - Wisconsin Madison

• File systems are not flexible enough to mould to differnt deployments (servers, desktop).
• Different reliability policies are helpful in different deployments.
• I/O shepherd allows specifying reliabity policies by the file system developers and takes care of enforcing those.
• All the I/O goes through the shepherd, it can do more I/O or modify the I/O as per the policies set for that I/O.
• Allows specifying fault-detection and recovery policies.

Generalized File System Dependencies - UCLA

• Writing individual policies, like journaling and soft-updates, for individual file systems is difficult and cumbersome.
• Idea is to be able to write such policies in a fs-agnostic way.
• Proposal is to handle each change going to the disk as patches. Each patch is a change going to a block of the disk.
• Patches are linked together as per the enforced dependencies (certain writes may be needed to happen before some other write).
• Policies then are implemented only dealing with patches.
• Patches are merged and rendered unimportant when possible.
• Allows easily write the policies and features and which can be applicable of any file system.