Building a secure Hadoop cluster requires protecting a number of services which comprise Hadoop infrastructure. If you are using CDH distribution, then Cloudera Manager (CM) is one of the components that needs to be secured. There is a good step by step guide in CM documentation, and it’s easy to follow for one server, but what when you have hundreds of them? There are different approaches to the problem of managing server’s configuration at scale, but I’d like to focus on Ansible which is a neat framework for parallel commands execution and complex rollouts.
This is a very short blog post to share a good news I learned last week at the great New Zealand Oracle User Group 2013 conference. During a keynote Tom Kyte mentioned that Oracle is going to introduce a Temporary Undo.
The answers to the questions like whether to patch now or wait a little? What quirks are there in that stunning new features? What are the limitations of that fancy index type, any working examples of a particular add-on, are best found in the blogs. This Log Buffer Edition provides you a window to those blogs out there.
This is the second article in a series about internals and performance of concurrent managers. In this post, we’ll take a look at three important settings that affect the performance of the concurrent managers: number of processes, “sleep seconds”, and “cache size”. This article might be a bit on the theoretical side, but it should provide a good understanding of how these settings actually affect the behavior and performance of concurrent managers.
I want to remind you, to let us know if you would like to come for the dinner at Pedro’s on Tuesday April, 23.
There are no rules for blogging. There cannot be any, because you cannot trap the wind in your hands. It’s innovation, it’s creativity, and it’s right out of the core of the technology from the bleeding edge. This Log Buffer drips into that, and brings you some of the finest posts.
This is the first article in a series about performance of concurrent processing. We’ll take a closer look at the internals of concurrent managers, the settings that affect their performance and the ways of diagnosing performance and configuration issues. Today we’ll start with an overview of the internal workflow of a concurrent manager process. Enjoy the reading!
How to resolve unusual situation where Oracle was writing trace files into the user directory instead of the usual oracle diagnostic destinations.
When reviewing the performance of some queries, it is sometimes useful to review the sessions statistics for each execution of the query. I had a situation that required to look at these stats so I could see why one query would run fast and sometimes much slower. I wrote a simple wrapper ksh shell script for the query. It saves the session statistics in a table before and after the execution of the query and then prints out the statistics in a pivot report. This turned out to be very handy to me and therefore I chose to share it with the world :)