Bookmarks

Results of the world finals of the ACM ICPC which is the worlds largest online programming contest for colleges. Interesting to note that the only Indian college that made it is IIT Madras and that to at position 47.

MemcacheQ is a memcachedb variant that provides a simple message quque service. Only two commands are used to operate the queue:

• append a message to the tail of queue
• pop a message from the head of queue

Tugela Cache is derived from Memcached. Much of the code remains the same. It is an on-disk cache wherein the Internal slab allocator replaced by BerkeleyDB B-Tree database.

Memcachedb is a distributed key-value storage system designed for persistence. It is NOT a cache solution, but a persistent storage engine for fast and reliable key-value based object storage and retrieval. It conforms to memcache protocol(not completed, see below), so any memcached client can have connectivity with it. Memcachedb uses Berkeley DB as a storing backend, so lots of features including transaction and replication are supported.

Google is launching an opensource browser. Details are available in a comic book published by them. Quite an interesting read.

An interesting article comparing .NET and Java application development times

Interesting comparison between the three w.r.t maintainability, scalability etc. A pretty long thread of comments (to be taken with bags of salt)

Good introductory article to db4o

Cache claims to be 5-10 times faster than relational databases, and supports SQL as well as Object based access to the database

List of books that Joel Spolsky recommends as a part of their Software Management Training Program. I can vouch for most of the books in this list. Must read for anyone

Brad Fitzpatrick talks about all cool things at LiveJournal in Scaling Storytime - Learn more about memcached, Perlbal, MogileFS, Gearman, TheScwartz, Djabberd and how they are used at Live Journal

John Allspaw, Engineering Manager at flickr (yahoo!), talks on how flickr uses ganglia to help with capacity planning. The talk covers a lot of the subleties and challenges facing hugely successful web services like flickr.

Code snippet that shows how you can capture a thumbnail image of a website from within a C# application

Tahoe, the Least-Authority Filesystem is a secure decentralized filesystem with a RESTfull web interface.It seems to have a capability based access control system. Also check out The Hack Tahoe! contest: http://hacktahoe.org/nathan_wilcox.html

A nice article with examples on using shared memory to communicate between processes

Dumbster is a very simple fake SMTP server designed for unit and system testing applications that send email messages. It responds to all standard SMTP commands but does not deliver messages to the user. The messages are stored within the Dumbster for later extraction and verification.

SubEthaSMTP a NIO based easy to use Java SMTP Server library

SLF4J is intended to serve as a simple facade for various logging APIs allowing to the end-user to plug in the desired implementation at deployment time. SLF4J API offers an advanced abstraction of various logging systems, including JDK 1.4 logging, log4j and logback. Features include parameterized logging and MDC support.

A semi-automated, largely passive web application security audit tool, optimized for an accurate and sensitive detection, and automatic annotation, of potential problems and security-relevant design patterns based on the observation of existing, user-initiated traffic in complex web 2.0 environments.

Detects and prioritizes broad classes of security problems, such as dynamic cross-site trust model considerations, script inclusion issues, content serving problems, insufficient XSRF and XSS defenses, and much more.

db4o is the open source object database that enables Java and .NET developers to store and retrieve any application object with only one line of code, eliminating the need to predefine or maintain a separate, rigid data model. It also supports replication

db4o is the open source object database that enables Java and .NET developers to store and retrieve any application object with only one line of code, eliminating the need to predefine or maintain a separate, rigid data model. It also has replication support

The Hadoop Summit brought together leaders from the Hadoop developer and user communities for the first time. Apache Hadoop, an open-source distributed computing project of the Apache Software Foundation, is a distributed file system and parallel execution environment that enables its users to process massive amounts of data. Slides and video from the presentations are available below.

Document explainaing the output of /proc/diskstats. Tools such as sar and iostat typically interpret these and do the work for you, but in case you are interested in creating your own tools, the fields are explained here.

An interesting article explaining the different IO schedulers in Linux and how to select the right one

An interesting article explaining the 4 different IO schedulers in Linux and how to select the right one

A nice tool for creating software mockups with a plugin for confluence

I heard about Extreme Interviewing from some of the people from Menlo that were at AgileCoachCamp2008. Its a neat strategy to assess candidates on how they will perform in the actual work environment (as close as possible) of the company and give the candidates a taste of what working at the company is really like. Its also interesting that they first filter the set of prospective candidates on good teamwork, communication and interpersonal skills and only then on technical skills. It looks like they are on to something there.

Apparently Oracle's Clustered filesystem is opensource and GPL

Compass is an open source project built on top of Lucene aiming at simplifying the integration of search into any Java application.

Luke is a handy development and diagnostic tool, which accesses already existing Lucene indexes and allows you to display and modify their contents in several ways

Provides a comparison of Lucene, OpenFTS, Xapian and other open source search engines

Neo is a graph database. It is an embedded, disk-based, fully transactional Java persistence engine that stores data structured in graphs rather than in tables. A graph (mathematical lingo for a network) is a flexible data structure that allows a more agile and rapid style of development. Neo4j offers massive scalability and can handle graphs of several billion nodes/relationships/properties on single-machine hardware with a powerful traversal framework for high-speed traversals in the node space.

how yahoo uses jsonp in their YWS API

Explains how to use JSONP to make cross site ajax calls work very well

A Python project that provides libraries for communication between network endpoints across NAT

By far the best online comparison chart and analysis of popular javascript/ajax libraries. jQuery and YUI come out as winners

An amazing slideshow on how to load YUI components on-demand thus reducing the payload and enhancing user experience

Excerpt: The problem in building distributed systems comes from the need to communicate and synchronize the different components of the system using networks that are prone to faults. In every distributed system (e.g. replicated databases or application server clusters) there are inherent uncertainties about the current state of remote components. Spread is a toolkit that provides a high performance messaging service that is resilient to faults across external or internal networks.

Wackamole is an application that helps with making a cluster highly available. It manages transitioning ip addresses from machines that go down to machines that are up within a cluster, while ensuring equal load distribution at all times

Explains how wordpress moved to nginx to loadbalance its web server clusters

The Xen hypervisor, the powerful open source industry standard for virtualization, offers a powerful, efficient, and secure feature set for virtualization of x86, x86_64, IA64, PowerPC, and other CPU architectures. It supports a wide range of guest operating systems including Windows®, Linux®, Solaris®, and various versions of the BSD operating systems. Xen was a project started in cambridge and subsequently bought over by Citrix

A really short but useful shellscript for connecting to all nodes of a cluster using ssh (also thru gateways and trapdoors) and sending commands to all nodes in parallel. It's using DCOP to remote-control a konsole process with the ssh connections in seperate tabs.

Csync2 is a cluster synchronization tool. It can be used to keep files on multiple hosts in a cluster in sync. Csync2 can handle complex setups with much more than just 2 hosts, handle file deletions and can detect conflicts. It is expedient for HA-clusters, HPC-clusters, COWs and server farms.

Contains better cluster monitoring, improved performance and tomcat 6 support

Interesting article on using Terracotta for managing Application preferences, global config etc without having to manage multiple config files. Terracotta takes care of modifications being available to all nodes in the cluster

Most OSs today use very similar cpu time scheduling algorithms,all based on the same basic ideas, but with OS-specific adaptations and extensions. What follows is a description of those rough basic ideas.