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Thursday
Apr162009

Paper: The End of an Architectural Era (It’s Time for a Complete Rewrite)

Update 3: A Comparison of Approaches to Large-Scale Data Analysis: MapReduce vs. DBMS Benchmarks. Although the process to load data into and tune the execution of parallel DBMSs took much longer than the MR system, the observed performance of these DBMSs was strikingly better. Update 2: H-Store: A Next Generation OLTP DBMS is the project implementing the ideas in this paper: The goal of the H-Store project is to investigate how these architectural and application shifts affect the performance of OLTP databases, and to study what performance benefits would be possible with a complete redesign of OLTP systems in light of these trends. Our early results show that a simple prototype built from scratch using modern assumptions can outperform current commercial DBMS offerings by around a factor of 80 on OLTP workloads. Update: interesting related thread on Lamda the Ultimate. A really fascinating paper bolstering many of the anti-RDBMS threads the have popped up on the intertube lately. The spirit of the paper is found in the following excerpt: In summary, the current RDBMSs were architected for the business data processing market in a time of different user interfaces and different hardware characteristics. Hence, they all include the following System R architectural features: * Disk oriented storage and indexing structures * Multithreading to hide latency * Locking-based concurrency control mechanisms * Log-based recovery Of course, there have been some extensions over the years, including support for compression, shared-disk architectures, bitmap indexes, support for user-defined data types and operators, etc. However, no system has had a complete redesign since its inception. This paper argues that the time has come for a complete rewrite. Of particular interest the discussion of H-store, which seems like a nice database for the data center. H-Store runs on a grid of computers. All objects are partitioned over the nodes of the grid. Like C-Store [SAB+05], the user can specify the level of K-safety that he wishes to have. At each site in the grid, rows of tables are placed contiguously in main memory, with conventional B-tree indexing. B-tree block size is tuned to the width of an L2 cache line on the machine being used. Although conventional B-trees can be beaten by cache conscious variations [RR99, RR00], we feel that this is an optimization to be performed only if indexing code ends up being a significant performance bottleneck. Every H-Store site is single threaded, and performs incoming SQL commands to completion, without interruption. Each site is decomposed into a number of logical sites, one for each available core. Each logical site is considered an independent physical site, with its own indexes and tuple storage. Main memory on the physical site is partitioned among the logical sites. In this way, every logical site has a dedicated CPU and is single threaded. The paper goes through how databases should be written with modern CPU, memory, and network resources. It's a fun an interesting read. Well worth your time.

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Wednesday
Apr152009

Implementing large scale web analytics

Does anyone know of any articles or papers that discuss the nuts and bolts of how web analytics is implemented at organizations with large volumes of web traffic and a critcal business need to analyze that data - e.g. places like Amazon.com, eBay, and Google? Just as a fun project I'm planning to build my own web log analysis app that can effectively index and query large volumes of web log data (i.e. TB range). But first I'd like to learn more about how it's done in the organizations whose lifeblood depends on this stuff. Even just a high level architectural overview of their approaches would be nice to have.

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Wednesday
Apr152009

Using HTTP cache headers effectively

Hi, Some time ago , martin fowler bloged about how HTTP cache headers can be very effectively used in web site design. http://www.martinfowler.com/bliki/SegmentationByFreshness.html How actively HTTP cache headers are considered in web site design? I think it is a great tool to reduce lot of load on server and should be considered before designing any complex caching strategy. Thoughts? Thanks, Unmesh

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Tuesday
Apr142009

Scalability resources

Tuesday
Apr142009

Designing a Scalable Twitter

There were many talks recently about twitter scalability and their specific choice of language such as Scala to address their existing Ruby based scalability. In this post i tried to provide a more methodical approach for handling twitter scalability challenges that is centered around the right choice of architecture patterns rather then the language itself. The architecture pattern are given in a generic fashion that is not specific to twitter itself and can serve anyone who is looking to build a scalable real time web application in the near future.

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Tuesday
Apr142009

Challanges for Developing Enterprise Application on the Cloud

This post I provided a summary of recent discussions outlining the main challenges that developers face today when deploying their existing JEE application to the cloud such as complexity, database integration, security, standard JEE support etc. In this post i also provided summary of how we managed to handle those challenges with our new Cloud Computing Framework by pointing to an existing production reference of a leading Telco provider.

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Monday
Apr132009

Benchmark for keeping data in browser in AJAX projects

Hi, We are using AJAX and see a lot of opportunity to keep session state on client browser with javascript objects. Is there any benchmark about how much data you can generally keep in javascript objects in browser? Thanks, Unmesh

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Monday
Apr132009

High Performance Web Pages – Real World Examples: Netflix Case Study

This read will provide you with information about how Netflix deals with high load on their movie rental website.
It was written by Bill Scott in the fall of 2008.

Read or download the PDF file here

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Friday
Apr102009

Facebook Chat Architecture

For those interested in building scalable systems, today I will speak about the Facebook Char architecture. Starting keynote:

''When your feature’s userbase will go from 0 to 70 million practically overnight, scalability has to be baked in from the start.''

Eugene Lutuchy, lead engineer on Facebook Chat

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Friday
Apr102009

Facebook's Aditya giving presentation on Facebook Architecture

Facebook's engg. director aditya talks about facebook architecture. How they use mysql, php and memcache. How they have modified the above to suit their requirements.

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