While migrating ADF applications from 11 to 12 we stepped on a known bug in ADF 12.2.1 Bug 22469635 : AF:QUERY COMPONENT BUTTONS DON’T WORK WHEN “DISCLOSED” SET TO “FALSE” Since this is not resolved yet we needed a workaround. There were search criteria with disclosed=”false” in pages with rich layout that the user should expand it only if he …
sparklyr: a test drive on YARN
sparklyr is a new R front-end for Apache Spark, developed by the good people at RStudio. It offers much more functionality compared to the existing SparkR interface by Databricks, allowing both dplyr-based data transformations, as well as access to the machine learning libraries of both Spark and H2O Sparkling Water. Moreover, the latest RStudio IDE v1.0 now offers native support …
Nonlinear regression using Spark – Part 2: sum-of-squares objective functions
This post is the second one in a series that discusses algorithmic and implementation issues about nonlinear regression using Spark. In the previous post we identified a small window for contribution into Spark MLlib by adding methods for nonlinear regression, starting with the definition and implementation of a general nonlinear model. We remind the reader that regression is essentially an …
Classification in Spark 2.0: “Input validation failed” and other wondrous tales
Spark 2.0 has been released since last July but, despite the numerous improvements and new features, several annoyances still remain and can cause headaches, especially in the Spark machine learning APIs. Today we’ll have a look at some of them, inspired by a recent answer of mine in a Stack Overflow question (the question was about Spark 1.6 but, as …
How to evaluate R models in Azure Machine Learning Studio
Azure Machine Learning Studio is a GUI-based integrated development environment for constructing and operationalizing machine learning workflows. The basic computational unit of an Azure ML Studio workflow (or Experiment) is a module which implements machine learning algorithms, data conversion and transformation functions etc. Modules can be connected by data flows, thus implementing a machine learning pipeline. A typical pipeline in …
Installing the additional R packages in Oracle Big Data Lite VM 4.5.0
Oracle has just released version 4.5.0 of the Big Data Lite VM which, when it comes to R, still suffers from the issues we had pinpointed for the previous version 4.4.0 (and then some). The first attempt to install the additional packages fails with a ‘cannot open URL’ error: Fortunately, the warning about the proxy helps to locate the issue, …
ViewCriteria issue when using more than once attribute with LOV based on switcher (Oracle JDeveloper 12.2.1.0)
Almost a year ago I wrote this post about a ViewCriteria issue when using the same attribute twice in Oracle JDeveloper 12.1.3.0. Now I came across another issue with ViewCriteria, in Oracle JDeveloper 12.2.1.0 this time, again related with a multiple insertion of an attribute but with a more complex scenario this time. Consider having an attribute with applied LOV that …
Manifest entry Weblogic-Application-Version causes log messages not to be shown on EM 12.2.1
Recently we migrated an ADF app from 12.1.3 to 12.2.1 and we faced a problem with the log messages in the application server. Specifically, the deployed application returned zero log messages when navigating to em>application>Logs>view Log messages. The log configuration and the search results are as you can see in the following screenshots: After many checks and dummy applications …
How to use SparkR in Cloudera Hadoop
Suppose you are an avid R user, and you would like to use SparkR in Cloudera Hadoop; unfortunately, as of the latest CDH version (5.7), SparkR is still not supported (and, according to a recent discussion in the Cloudera forums, we shouldn’t expect this to happen anytime soon). Is there anything you can do? Well, indeed there is. In this …
Bulk load data to HBase in Oracle Big Data Appliance
I ran into an issue recently, while trying to bulk load some data to HBase in Oracle Big Data Appliance. Following is a reproducible description and solution using the current version of Oracle Big Data Lite VM (4.4.0). Enabling HBase in Oracle Big Data Lite VM (Feel free to skip this section if you do not use Oracle Big Data …
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