Posts Tagged ‘Yahoo’

Java Technologies at Yahoo!

Tuesday, August 5th, 2008

Yesterday, I attended a talk at SDForum presented by Dean Yu and Joshua Blatt of the Java platform team at Yahoo! The Java platform team centralizes the Java efforts for Yahoo’s non-open source efforts. I say non-open source as the platform team covers everything except things like Hadoop, etc. which are in the public domain.

Java as a technology is not native to Yahoo! The platform at Yahoo! was primarily C/C++ and PHP at the frontend (mostly). Java came through several acquisitions which were running Java stack, notably:

  • 1998 Classic Games, Sprtasy
  • 2002 Hotjobs
  • 2003 Overture (Altavista)
  • 2004 Kelkoo, Musimatch

Here are the raw bytes from the session:

  • Tomcat + jboss efforts for securing them
  • Mostly LAMP stack at Yahoo!
  • Rate limiting using Apache modules 
  • Runs apache in multiple process mode
  • Y! data streams for keeping application specific stores and pushing data around (Yahoo’s proprietary message bus like implementation)
  • Integration using JNI to C++ code using Swig for wrapper generation
  • All security related code is in C++; helps maintain a single language code-base. Hence, wide JNI use from app tier
  • Uses IPC Bridge for coarse grained calls to non-thread safe libraries (JNI has multi-threading issues)
  • Group dedicated to creating JNI wrappers of native code
  • JNI performance FUD
  • Java to Native C++ code via JNI < 20 nano seconds (Cool!) compare this with Java to Java < 1 nano seconds. Big difference but nano seconds compared to network latencies of seconds
  • String functions to native code via JNI take > 3ms coz of UTF-16 to UTF-8 character conversion issues
  • JNI Multi-threading issues are solved by IPC bridge shared memory and TCP over loopback
  • JSVC Apache commons daemon for loading privileged data during Tomcat startup and then running in low privilege mode
  • Like Multi-process Apache, a new architecture for multi-process Tomcat being baked
  • Software project management using Maven (Maven — awww!)
  • Automatic builds using Cruise control and Hudson
  • RPM-based software deployment to 100s of nodes



Yahoo, Google after Rediff’s poor customer service: A riff on their customer e-mail

Monday, July 16th, 2007

I was surprised to see a lot of hubub around Rediff. Only 2 days ago, I had my own bout of poor customer experience with Rediff. Have you seen their shopping site? Sucks, big time. The strategy may be good but their execution, quality control and customer service is really poor. I purchased some floral basket to be delivered for a birthday. A dozen roses tied as a bouquet was delivered instead. More than 24 hours has passed and there is no response from customer support.
Look at their e-mail below, the development team does not even bother to test the e-mail, The e-mail is annotated with my riff.
More coverage at: