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Posts Tagged ‘performance monitoring’

How Twitter Operates Its IT infrastructure: From Process to Tools

December 6th, 2010 No comments

This post is based on my notes taken at the talk by John Adams at LISA 2010 conference. Any mistakes, if any, are all mine. Should you be interested in other sites, check out Google, Facebook, LinkedIn.

As one of the leading social Web site with 165M users, Twitter demands a huge infrastructure support its operation. There are 700M searches and 1,000 tweets per second and can go up to almost 4,000 at peak. The number of tweets is not that impressive, but these tweets need to be distributed to numerous followers which could be several millions after one account.

These days Twitter gets 75% traffic from API and 25% from the Web. The new twitter.com Web interface heavily uses AJAX and acts as API client to its backend.

As John put it, “nothing works the first time.” His recommendation is to use the best available technology for scaling. You will need to plan and build for more than one time to get it right.

vSphere Performance Counters for Monitoring ESX and vCenter

December 3rd, 2010 11 comments

VMware vSphere provides comprehensive performance metrics for your needs on performance monitoring and diagnosis. These stats are available through not only vSphere Client but also vSphere APIs. To understand the overall performance management concepts, you want to read this article: Fundamentals of vSphere Performance Management.
Once having the basics, you may wonder what types of stats are exposed. The following table summaries all the 315 performance counters available in vSphere 4.1. As you might have guessed, the information is generated using open source Sphere Java API and then imported into WordPress using WP-Table Reloaded. You can easily sort and search the table.

Update: Carter Shanklin and Luc Dekens have articles on performance counters as well: