TensorFlow – Getting Started with Docker Container and Jupyter Notebook

I'm studying Machine Learning and would like to share some intro experience working with TensorFlow. To get started with TensorFlow you need to install it, easiest way (at least for me) was to run TensorFlow using Docker. Read installation instructions - Installing TensorFlow.

Once TensorFlow Docker image is installed. I suggest to create container in detach mode (--detach=true) and provide port for Jupyter UI. Make sure to provide meaningful name for Docker container:

docker run (more...)

Taking Pivotal Cloud Foundry Small Footprint for a test drive

Pivotal Cloud Foundry (PCF) now has a small footprint edition. It features a deployment configuration with as few as 6 VMs. Review the documentation for download and installation instructions as follows


There was also a Pivotal blog post on this as follows:


As you can see from this image it's considerably smaller control plane that's obvious.

It is important to understand what the limitations of such an install (more...)

Scaling Oracle using NVMe flash

Attend the free webinar by storage expert Venky Nagapudi and learn how to improve the performance of your Oracle Database using new storage technologies such as NVMe flash. 

About the Webinar
Growth in users and data put an ever-increasing strain on transactional and analytics platforms. With many options available to scale platforms, what are the considerations and what are others choosing? Vexata’s VP of Product Management, Venky Nagapudi covers how the (more...)

How to Setup Node.js and Oracle JET on Oracle Linux

What if you want to develop Oracle JET in Oracle Linux? Certainly this is possible - both Node.js and Oracle JET run on Oracle Linux or any other Linux distribution. If you follow Oracle JET Setup Guide, you will see Node.js is listed as prerequisite. But it may not be exactly straightforward to install Node.js on Oracle Linux. Below I will guide you through the steps.

Run command to install development (more...)

Using Spring Boot Actuator endpoint for Spring Boot application health check type on PCF

An application health check is a monitoring process that continually checks the status of a running Cloud Foundry application. When deploying an app, a developer can configure the health check type (port, process, or HTTP), a timeout for starting the application, and an endpoint (for HTTP only) for the application health check.

To use the HTTP option your manifest.yml would look like this

- name: pas-cf-manifest
  memory: 756M
  instances: 1

ADF Performance on Docker – Lighting Fast

ADF performance depends on server processing power. Sometimes ADF is blamed for poor performance, but in most of the cases real issue is related to poor server hardware, bad programming style or slow response from DB. Goal of this post is to show how fast ADF request could execute and give away couple of suggestions how to minimize ADF request time. This would apply to ADF application running on any environment, not only Docker. I'm (more...)

ADF Performance Story – This Time Developer Was Wrong

ADF is fast. If ADF application is slow, most likely this is related to development mistakes. I would like to tell you one story, based on my ADF tuning experience. Problem description: ADF application runs fast in DEV, when DB size is small. Same application runs slow in TEST/PROD, when DB size is large. Question - what is slow. Answer - slow means forms are loading slow. Ok, lets go to the story.

Developer decides (more...)

Testing network connectivity from Cloud Foundry Application Intances

This app below simply tests whether a host:port is accessible from a CF app instance. For example can my application instance access my Oracle Database Instance running outside of PCF given application instances need network access to the database database for example.

You can use bosh2 ssh to get to the Diego Cells if you have access to the environment or even "cf ssh" if that has been enabled.

GitHub URL:



Just installed Pivotal Cloud Foundry, what’s next should I login to Apps Manager?

I get this question often from customers. Pivotal Cloud Foundry has just been installed and the API endpoint to target the instance is working fine. In short we want to do the following before we get developers onto the platform to ensure we no longer using the UAA server admin login details from the CLI or Apps Manager UI.

  • Create a new ADMIN user which will be used to configure Apps Manager ORGS and spaces (more...)

Selective persistence of Oracle Diagnostic Logging (ODL) output

Background and Goal

In any application, logging is widely used for diagnostics and debugging. 

Logging at various "checkpoints" (such as entering with request, exiting with response, error handler) in the application can provide a fairly reliable way to trace the execution path of the application - which a subsequent sweep or count can be used to report on. When the logs are regularly analysed and reported on, anomalies can get flagged up proactively and (more...)

Your DBA Career in the Age of Oracle Cloud

Attend the free webinar by Oracle ACE Director Craig Shallahamer and learn how the Oracle Cloud and the Oracle 18c autonomous database changes your role as an Oracle DBA.
About the Webinar
The cloud is a change that all Oracle DBAs must face. The cloud is here stay, and that means Oracle DBAs need to adapt or get out of the game. It makes no difference if you are a new Oracle DBA or retiring (more...)

Geographical clusters with the biggest concentration of web services

From a data set of approximately 145 million IP addresses running at least one publicly accessible web service (such as a website), I was able to determine these 20 geographic "clusters".

Note that these are not "20 locations with the most number of web services" but data set clustered into 20 geo locations - similar to centres of gravity. (Which is why some of the clusters appear in the sea). It is not surprising that (more...)

MAF: Be careful how you build your APK

So that has been a while.... 1 year and 1 day to be exact. Today I encountered a really weird issue in MAF. Yes, we are still using that in some projects. We are using 2.4.1 to build an app for a company that needs offline storage and sync. As MAF has this incorporated in the framework, and the customer has lots of ADF developers, the choice for MAF was made. Anyway, back (more...)

Raw results – countries list with total IP (IPv4) addresses


Presented below is a list of countries (country codes) and the total count of live IPv4 addresses as counted from the scan data of 1st October 2017

The numbers definitely look incorrect and total up to only 145,430,195 - I will continue to investigate why, but they seem to be in proportion. 
It is likely that scans.io are only able to gather data about live IP addresses (more...)

How many programmers does it take to update a Wikipedia page?

......or what it took to count the number of IPv4 addresses in every country (as of 1st October 2017). 

This Sunday, I found that the Wikipedia page on List of countries by IPv4 address allocation was using data from 2012. I wondered what it might take to add more up to date information on that page. During a recent course I attended, I got to know about scans.io - a fascinating project that (more...)

Pivotal Cloud Foundry 1.12 on Google Cloud Platform with VM labels

Once PCF is installed on GCP it's worth noting that viewing the "Compute Engine" labels gives you as indication of what VM each CF service is associated with. The screen shots below show's this.

Comprehensive automated test coverage tool kit – Service bus (and ICS)

If we are not test first (or at least test alongside) programming, we are essentially debug later programming (See "Physics of Test Driven Development").

If the enterprise service bus sits in the middle of an organisation's messaging and integration landscape, there are some key architectural principles that help in getting the best out of any service bus solution:
  • It is not the place for business logic but for integration logic i.e. heavy on (more...)

Updating Cloud Foundry CLI using Brew

Need to upgrade the CF CLI using brew it's as simple as below. Go to love brew

pasapicella@pas-macbook:~$ brew upgrade cf-cli
==> Upgrading 1 outdated package, with result:
cloudfoundry/tap/cf-cli 6.31.0
==> Upgrading cloudfoundry/tap/cf-cli
Warning: Use cloudfoundry/tap/cloudfoundry-cli instead of deprecated pivotal/tap/cloudfoundry-cli
==> Downloading https://cli.run.pivotal.io/stable?release=macosx64-binary&version=6.31.0&source=homebrew
==> Downloading from https://s3-us-west-1.amazonaws.com/cf-cli-releases/releases/v6.31.0/cf-cli_6.31.0_osx.tgz
######################################################################## 100.0%
==> Caveats
Bash completion has been installed to:
==> Summary
????  /usr/local/Cellar/cf-cli/6.31.0: 6 files, 17.6MB, built in 16 seconds

pasapicella@pas-macbook:~$ cf --version
cf version 6.31.0+b35df905d.2017-09-15

Webinar: Version Control for the Oracle Database

Version control of tables and PL/SQL code in the Oracle Database has always been challenging. Database programmers lack the tools that make version control easy for developers who code with file based programming languages such as Java and JavaScript. In fact, this is one of the primary reasons why large software teams avoid schemas and writing code in the database.

In this presentation you will learn how Gitora 3 can help you use Git, the (more...)

Using Cloud Foundry CUPS to inject Spring Security credentials into a Spring Boot Application

The following demo shows how to inject the Spring Security username/password credentials from a User Provided service on PCF, hence using the VCAP_SERVICES env variable to inject the values required to protect the application using HTTP Basic Authentication while running in PCF. Spring Boot automatically converts this data into a flat set of properties so you can easily get to the data as shown below.

The demo application can be found as follows