Skip to main content

Posts

Showing posts from 2013

So you have your website deployed in PROD ... now what ??

Posting on behalf of Usr.Web.Speed - My previous job had been to architect and develop websites for various customers. During that time my team and I have architected and developed various web applications mainly for enterprises. (But below info is not restricted to enterprises) Other than the usual development and testing tasks involved, our focus area was to abide by multiple SLAs. One of the primary SLAs was to provide the users of our websites a very low (usually subsecond) response time (or page load time). To adhere to this SLA, we did multiple activities, in code, process as well as infrastructure. These include (but not limit to) - Using best practices including (http://developer.yahoo.com/performance/rules.html) Determining the optimum number of calls to the databases, open connections, etc. Providing the fastest mechanisms to download associated content (such as stylesheets, JS files, etc. over CDN) And debugging the reason for the slowness of the websites, when

Changing JAVA_HOME on a HDP 1.1 Hadoop on Windows Setup

We were setting up a small cluster of  Hadoop for some requirements, and decided to go with the HortonWorks release of Hadoop. ( HDP 1.1 for Windows ). After installing, we realized that for some reason the Oozie service was not starting up . (we tried both the CLI command provided with the HDP installation, as well as trying to manually start the service via services.msc). Looking through the log files (<HDP 1.1 installation path>\oozie-<version>\Service directory, specifically the oozieservice.out.log file) we found the error -    and so realized that Oozie server is dependent on JDK. It does not work with only JRE. To correct this we uninstalled JRE, and installed JDK. We also manually modified the JAVA_HOME environment variable to point to the new installation path. And then Oozie server started working all fine. But all the rest of the services (hadoop jobtracker, hadoop datanode etc.) stopped starting. Checking the logs of the services, we found that all th