It all worked fine, but I later had some trouble. My site wasn’t answering anymore and I couldn’t connect with ssh, timeout. I now think that I must have made an error with the credential. But at the time I didn’t know and, following some advice found on internet, I restarted my instance: I still couldn’t connect, but this time with connection refused…
After looking at the console log of my instance, I found out that ssh didn’t start, due to some incorrect owner rights on some system directories. But how to correct some file-system ownership when I cannot connect to the instance !?!
The solution, in short :
Shutdown the instance
Disconnect the EBS volume
Create a new instance (same config) and connect the EBS of the 1st instance on it
I am one of the original IT of the ICA start up. We develop big-compute technologies and BI for financial risk analysis. We use all the new cloud tech that can help us leverage some very high computing and distributed data challenges.
My role span from implementing the distributed computing engines to the pricer of derivative products and financial metrics. One of my main specialty is to cope with all expertise of the companies, cloud IT to financial math. And as such, I have a central position regarding the design of the main computational workflow.
In the xdata project I had to convert a stand alone Spring web app into a “big-data” web app running on a hadoop cluster. To do that, I chose to use apache spark and spark-hive because it provided the most practical interface. I however could not find any documentation or tutorial on such use of spark in java spring web application.
To test how to setup such application, I made two getting-started prototypes:
A spring+spark web app: it implements a very simple web service that reads and converts files either on local file system or on hdfs, using spark.
The main difficulty was about run-time dependencies: dependencies used for compilation (such as provided through maven) were not working together at run-time (at the time of writing this post).
To run a stand alone app, one should add the `$SPARK_HOME/lib/spark-assembly-X.X.X-hadoopY.Y.Y.jar` (provided by the spark installation) to the classpath. For the spark-hive case, the datanucleus dependencies found in spark lib should also be added. Because, web app are run by a servlet container, such as tomcat or jetty, this jar should be added:
Either to the war file, such as recommended for web app. It is however a 140Mb dep. This is what is used in the spring+spark web app.
Or to the class path of the servlet container. This is what is used in the spring+spark-hive web app which is added to the maven jetty plugin.
For my (professional) work, I chose the second solution: add the spark jar to maven jetty plugin which is used during development, and I included the jetty-runner to the project which I run with spark jar added to the classpath (using the `–jar` option).
Obsolete redhat has changed its cloud on September 2017 and I moved to AWS
Here is a simple method to deploy a wordpress server on the redhat cloud and attach it to a domain name, for free. This is what I have done to host this site.
Create a wordpress server:
Create an account on OpenShift, or login
Add an application, and select “wordpress”
If the account was just created, choose its (unique) namespace
Choose the application name and fill up the form
Go to application-namespace.rhcloud.com site to create the wordpress user account
Add content and customize the site directly from wordpress
Access the server:
install the rhc command, then run rhc setup
log in with ssh and/or git clone the wordpress repo from openshift
The url for ssh and git can be found on the page of the application once logged in openshit.
Note for git: content should be added in the .openshift/[themes|plugins|…] folder of the repo. It will be copied in the suitable folder of the wordpress server (i.e. $OPENSHIFT_DATA/[themes|…]) by git push.
Finally, to attach this application to a domain name:
The XData project is a french collaborative project between industrials, startups as well as big companies, and academics. Its main objective is to develop innovative commercial product constructed from the integration of private data with open data.
I mostly work on the xdata “movement analytics” application. More specifically on:
The data integration of the movement data type: any type of data that represent people movement such as housing or companies moving, as well as tourist displacement. The integration is done in two main parts: first a generalized data structure cas defined with a generic data descriptor to allow importing any data set containing movement data ; second an automated data query algorithm has been defined to select suitable movement entry with respect to geographical and temporal area and granularity.
The transfer of the stand alone prototype of the web application, which use mysql and spring technologies, on the hadoop cluster of the xdata project, in particular using spark and hive.
With several of the main actors in root system measurement and analysis, we have develop the RSML file format. It allows to store 2D or 3D image metadata, plant and root properties and geometries, continuous functions along individual root paths and a suite of annotations at the image, plant or root scales, at one or several time points. The plant ontologies are used to describe botanical entities that are relevant at the scale of root system architecture.