Purpose of Load and Stress testing The key goals of load testing are: Find out whether your website can support the expected # of concurrent users. At what load does the app break? To do that, you normally follow these steps: Identifying the primary user path Identifying the expected # of concurrent users. (Both now [...]

Introduction Caching is a crucial performance tuning strategy, especially your system has high read to write ratio. You can perform caching strategy at different levels from client browser cache all the way to disk cache at server side. Lets take a brief look at where we can cache based on the invocation path for a [...]

Push data to client Traditional web application is based on request and response model that information is delivered as a single payload and then immediately close the connection to the client. To keep the client in sync, we normally pull the server periodically. This approach may generate unacceptable load to the server. To solve this [...]

Open source reporting My company needs a reporting engine but it doesn’t want to go for the expensive commerical ones like MicroStrategy. In fact, I don’t know why we need to pay so much because there are tools out there for FREE. As usual, I googled the Net and found out two seemingly promising open [...]

Linux File System Basic Ext3 (successor of Ext2) is the standard file system for Linux: It is robust, fast and suitable for all fields of use. The main difference between them is that Ext3 has a journal that records the pending operations for fast recovery purpose in the event of system crash. This record guarantees [...]

Recently, I want to extend the LineChart in Flex. I want to have line chart with event annotated like Google Finance.   First of all, I googled the Net to see whether anyone had already done it. It was even better if I could find any open source project related to this. Below are the [...]