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The Simple Logging Facade for Java (SLF4J) serves as a simple facade or abstraction for various logging frameworks (e.g. java.util.logging, logback, log4j) allowing the end user to plug in the desired logging framework at deployment time. Before you start using SLF4J, we highly recommend that you read the two-page SLF4J user manual. Note that SLF4J-enabling your library implies the addition of only a single mandatory dependency, namely slf4j-api.jar. If no binding is found on the class path, then SLF4J will default to a no-operation implementation. In case you wish to migrate your Java source files to SLF4J, consider our migrator tool which can migrate your project to use the SLF4J API in just a few minutes. In case an externally-maintained component you depend on uses a logging API other than SLF4J, such as commons logging, log4j or java.util.logging, have a look at SLF4J's binary-support for legacy APIs.

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Retrieve Oracle version information This Oracle tutorial explains how to find the Oracle version information with syntax and examples. Description You can check the Oracle version by running a query from the command prompt. The version information is stored in a table called v$version. In this table you can find the version information for Oracle, PL/SQL, etc. Syntax DataStax Cassandra 0.8 Documentation Effective tuning depends not only on the types of operations your cluster performs most frequently, but also on the shape of the data itself. For example, Cassandra’s memtables have overhead for index structures on top of the actual data they store. If the size of the values stored in the columns is small compared to the number of columns and rows themselves (sometimes called skinny rows), this overhead can be substantial.

HttpClient - HttpClient Home End of life The Commons HttpClient project is now end of life, and is no longer being developed. It has been replaced by the Apache HttpComponents project in its HttpClient and HttpCore modules, which offer better performance and more flexibility. Introduction The Hyper-Text Transfer Protocol (HTTP) is perhaps the most significant protocol used on the Internet today. Web services, network-enabled appliances and the growth of network computing continue to expand the role of the HTTP protocol beyond user-driven web browsers, while increasing the number of applications that require HTTP support. World Wind Java Demo Applications and Applets The applications and applets here demonstrate some of World Wind’s rich capabilities. Also see World Wind Europa Challenge site for a collection of applications created by the World Wind Europa Challenge teams. Known Issues Running With Java 7 All Platforms World Wind applications and applets fail with a CertPathValidatorException with Java 7 update 9 and earlier.

NodeTool More and more instrumentation is being added to Cassandra via standard JMX apis. The nodetool utility (nodeprobe in versions prior to 0.6) provides a simple command line interface to these exposed operations and attributes. See Operations for a more high-level view of when you would want to use the actions described here. Note: This utility currently requires the same environment as cassandra itself, namely the same classpath (including, and a valid storage-conf property. Running bin/nodetool with no arguments produces some usage output. The -host argument is required, the -port argument is optional and will default to 8080 if not supplied.

gson - Project Hosting on Google Code Gson is a Java library that can be used to convert Java Objects into their JSON representation. It can also be used to convert a JSON string to an equivalent Java object. Gson can work with arbitrary Java objects including pre-existing objects that you do not have source-code of. World Wind JAVA SDK Welcome: Here you will find the World Wind SDK for Java. With this, developers can embed World Wind technology in their own applications. Many resources are available at to help you understand and use World Wind. Current releases: Java Weak Reference Releasing unused objects for garbage collection can be done efficiently using java weak reference. Yes. weak reference is related to garbage collection. In java we need to not anything explicitly for garbage collection (GC), this memory management overhead is taken care by java run-time itself. Then what is the use of java weak reference? Let us see an example scenario, which will help us understand the problem in detail. Before that, we should be aware there are four types of references in java and they are strong reference, weak reference, soft reference and phantom reference.

Cassandra Write Performance – A quick look inside Application Performance I was looking at Cassandra, one of the major NoSQL solutions, and I was immediately impressed with its write speed even on my notebook. But I also noticed that it was very volatile in its response time, so I took a deeper look at it. First Cassandra Write Test I did the first write tests on my local machine, but I had a goal in mind. Design Patterns in Java Tutorial Design patterns represent the best practices used by experienced object-oriented software developers. Design patterns are solutions to general problems that software developers faced during software development. These solutions were obtained by trial and error by numerous software developers over quite a substantial period of time. This tutorial will take you through step by step approach and examples using Java while learning Design Pattern concepts. This reference has been prepared for the experienced developers to provide best solutions to certain problems faced during software development and for un-experienced developers to learn software design in an easy and faster way. Before you start proceeding with this tutorial, I'm making an assumption that you are already aware about basic java programming concepts.

Linux performance basics I want to write about Cassandra performance tuning, but first I need to cover some basics: how to use vmstat, iostat, and top to understand what part of your system is the bottleneck -- not just for Cassandra but for any system. vmstat You will typically run vmstat with "vmstat sampling-period", e.g., "vmstat 5." Java concurrency (multi-threading) - tutorial Java concurrency (multi-threading) - Tutorial Copyright © 2008-2015 vogella GmbH Java concurrency (multi-threading) This article describes how to do concurrent programming with Java.

Logging facade that allows various implementations to be used like log4j, java logging, commons logging. The chap that made this library has his own logging framework that is supported( by superunknown Apr 10