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EIONET Content Registry (CR) software.


CR is a search engine for structured data. The data is collected from various Semantic Web / Linked Data nodes on the Internet, and stored as RDF triples in a triple store.

The following sections describe how to install and run CR. Installation instructions can also be found at

1. Download and install Java, Tomcat and Maven.

CR runs on the Java platform, and has been tested to run on Tomcat Java Servlet Container. CR source code is built with Maven.

Please download all of these software and install them according to the instructions found at their websites.

The necessary versions are as follows:

  • Java 1.6 or 1.7 ( higher versions are not recommended due to incompatibility )
  • Maven 3.0.5 or higher
  • Tomcat 6.0 or higher

2. Download and install Virtuoso

CR uses OpenLink Virtuoso as its backend for relational database and triple store. Download Open-Source Edition of Virtuoso from here

CR has been tested and run on Open-Source Virtuoso version 6.1.5.

To install Virtuoso’s Open-Source Edition, follow these guidelines:

There’s more useful information about Virtuoso’s Open-Source Edition here:

NB!!! For security reasons, be sure to change your Virtuoso administrator password to something other than the default!

CR will ask virtuoso to load files from the temporary directory. You must ensure the the values for harvester.tempFileDir and filestore.path in are listed for DirsAllowed in virtuoso.ini.

3. Download, configure and build CR source code

The CR source code is kept in GitHub repository at

Install a Git client of your choice, and clone CR source code into a directory that is denoted by CR_SOURCE_HOME in the below instructions.

Before you can build CR source code, you need to set your environment specific properties. For that, make a copy of in CR_SOURCE_HOME, and rename it to Go through the resulting file and change properties that are specific to your environment or wishes. Each property’s exact meaning and effect is commented in the file.

Now you are ready to build your CR code. It is built with Maven. The following command assumes that Maven’s executable (mvn) is on the command path, and that it is run while being in CR_SOURCE_HOME directory:

shell> mvn clean install

3.1 Unit tests

When you ran the above command you probably noticed that it ran the unit tests. These are designed to not require any external assets such as a database, mail server etc. It is safe to run them. In case you don’t want to, you can add -Dmaven.test.skip=true argument.

4. Import CR database creation scripts

The following commands shall import scripts that create necessary users, table structures, indexes and other CR setup information into Virtuoso.

All of these commands use Virtuoso’s Interactive SQL (ISQL) utility to import the scripts. They assume Virtuoso is running on localhost, and listens to its default port which is 1111. Please change these on the command line accordingly if this is not the case.

Options -U and -P indicate user and password under which the command is run. All the below commands shall be executed as ‘dba’ user.

The scripts are located in CR_SOURCE_HOME/sql/virtuoso/install directory, and the following commands should be executed while being in that directory. The commands also assume that ISQL executable is on the command path (it is located in VIRTUOSO_HOME/bin directory).

Create necessary Virtuoso users for CR:

shell> isql localhost:1111 -U dba -P password < 1_create_users.sql

Set up the triple store’s full text indexing

shell> isql localhost:1111 -U dba -P password < 2_setup_full_text_indexing.sql

5. Integration tests

There are 2 ways to run integration tests: Using a docker or manually.

5.1 Automated test execution using Docker(there are test failures)

You need to have docker installed. Then execute the following command:

shell> mvn -Pit clean verify

The integration test will start up a virtuoso database on port 1112, then the application in Tomcat. The application will run the Liquibase scripts on the database, and then the integration tests will be run by the Maven program - not from the instance of Tomcat or Virtuoso.

5.2 Manual Test Execution (All tests pass)

  1. create a folder for test Virtuoso

  2. copy file virtuoso.ini from Virtuoso folder to the created folder

2.1:For a Linux Environment
An example virtuoso.ini file in typical installation can be found at: /etc /virtuoso-opensource-<version_number>
/virtuoso.ini where virtuoso installs a default instance .

  1. Make adjustements in the copied file. At least ServerPort in sections Parameters and HTTPServer sections have to be changed

3.1:For a Linux Environment
In the virtuoso.ini file, in The sections [Database] and [TempDatabase] , change the files location path to a new
folder you wish to place virtuoso test Database + server files.
Old: DatabaseFile = /var/lib/virtuoso-opensource-6.1/db/virtuoso.db
Updated: DatabaseFile = /home/user1/cr-virtuoso-test/db/virtuoso.db
Notice that everything after the /db must remain as is.
Also in the [HTTPServer] section, change “ServerRoot” to also point to the above created folder
Old: ServerRoot = /var/lib/virtuoso-opensource-6.1/vsp
Updated: ServerRoot = /home/user1/cr-virtuoso-test/vsp

  1. Install the test server as another service as described in Virtuoso documentation.

4.1. For Linux Environment
As soon as virtuoso is installed in the system, one may navigate to the location of the newly modified virtuoso.ini

file and execute the following command:
shell> virtuoso-t -fd
If the virtuoso.ini file is correct, the test virtuoso instance will start.
The DB files will be placed in the newly created directory as explained in step 3.1.

  1. Create needed users for tests using this script:CR_SOURCE_HOME/sql/virtuoso/unittest/1_create_testuser.sql
    and this script: CR_SOURCE_HOME/sql/virtuoso/install/1_create_users.sql
    (assuming the test server is running on port 1112)

shell> isql-vt localhost:1112 -U dba -P password < 1_create_users.sql

  1. Add the test instance server parameters to

  2. Run mvn -Pmanualit clean verify

All integration tests pass in the master branch.

6. Conditional: register Eionet’s GlobalSign CA certificates in your JVM.

This step is required only if you configured CR to use EEA’s Central Authentication Service (CAS) in step 3. In other words: if you pointed and to EEA’s CAS server. In such a case you need to register Eionet’s GlobalSign CA certificates in the JVM that runs the Tomcat where you deploy CR.

The steps are as follows (note that the expected password for the keystore is “changeit”, but don’t change it):

a) Go to [] and download the certificates called GlobalSign-Root-CA.crt and GlobalSign-Domain-Validation- CA.crt to a temporary directory.

b) Check that the GlobalSign-Root-CA.crt certificate is not already in the keystore: shell> openssl x509 -fingerprint -md5 -noout -in GlobalSign-Root- CA.crt

Compare the fingerprint to what is already in the keystore: shell> keytool -list -keystore $JAVA_HOME/jre/lib/security/cacerts

c) Import the certificate from the .crt file into your JVM’s default keystore of trusted certificates. Example:

shell> keytool -import -file GlobalSign-Root-CA.crt -alias globalsignca28 -keystore $JAVA_HOME/jre/lib/security/cacerts

This certificate will be added under alias “globalsignca28”.

d) Do steps b) and c) for GlobalSign-Domain-Validation-CA.crt as well. Store it under the alias ‘globalsigndomain14’.

7. Deploy CR web application and run Tomcat

If the build went well, you shall have cr.war file in CR_SOURCE_HOME/target directory. Now all you have to do is to simply copy that file into Tomcat’s webapps directory. Optionally, you can also deploy the WAR file via Tomcat’s web console, but be sure to have made the following Tomcat configuration trick, before running Tomcat.

Before you run Tomcat, you need to change the way Tomcat handles URI encoding. By default, it uses ISO-8859-1 for that. But CR needs UTF-8. Therefore make sure that the tag in Tomcat’s server.xml has the following attributes:


Once Tomcat is running, open CR in the browser. It’s application context path is /cr, unless you renamed cr.war to something else or you chose to deploy CR into a virtual host.

8. Overriding settings by environment variables (Docker)

All the settings in (that are usually filled at build time using as source) can be overriden by environment variables, using the following rules:

  1. The env variable must start with _CR__
  2. After CR_ the variable name continues with the property name from, but the dots must be replaced by underscores (as OS vars with dots are not permitted)
  3. The variable name is not case-sensitive
  4. The setting MUST still exist in (otherwise you can have identification problems because of case sensitivity)
  5. The property names in may be different than the ones in, so make sure you use the names from in the environment variables.

Sample: to override application.displayName you can use the following environment variables:



CR_application_displayName = NewApplication

Using both styles is not an issue, but using both styles with the same property and different values may cause problems, as the evaluation order is not guaranteed.

For debug purposes, the application will report at startup the settings that are overriden, like this:

Setting harvester.tempFileDir overridden by ENV variable (old value /var/tmp, new value /var/tmp/cr)

9. Tips for Handling Virtuoso Errors

9.1 Virtuoso Error : “Message: SR008: Function sequence_set needs an

integer as argument 2, not an arg of type DB_NULL (204)” or similar error

  • Solution:
    It may be an indicator that we are trying to insert a wrong or null value to a virtuoso column. The best way to overcome it is to try to print from the code, the query to be executed along with the actual values, and run the query manually to virtuoso server. In this case where this error occurs, we were passing null value to an integer not null column.

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