Lesson Start FCRepo and Solr

Goals

• Install FCRepo and Solr
• Learn to start and stop FCRepo and Solr

Explanation

In order to use blacklight and hydra-head you need an installation of Solr. In addition, hydra-head requires a copy of Fedora. Fedora and Solr are both Java web applications.

For developer environments, we have created a solr_wrapper and fcrepo_wrapper -- commands to assist you in starting Solr and Fedora. Whenever you need Fedora and Solr running in your development environment, just start or stop that copy of solr_wrapper or fcrepo_wrapper

TIP DO NOT use solr_wrapper or fcrepo_wrapper for production installations.

Install fcrepo_wrapper and solr_wrapper Gems

Step 1: Install fcrepo_wrapper

gem install fcrepo_wrapper

Step 2: Install solr_wrapper

gem install solr_wrapper

Using FCRepo and Solr

TIP Running solr_wrapper in a tmux panel can silently fail. Use a separate new terminal window.

Step 1: Start Solr

Open a new terminal window and type:

cd <hydra-demo app path>
solr_wrapper -d solr/config/ --collection_name hydra-development

You can check to see if Solr is started by going to http://localhost:8983/

Step 2: Start FCRepo

Open a new terminal window and type:

fcrepo_wrapper -p 8984

You can check to see if FCRepo is started by going to http://localhost:8984/

Step 3: Make git ignore the fcrepo4-data directory

We want git to ignore the fcrepo4-data directory for the same reasons that we don't check our development databases into git -- because it's big and bulky and you don't actually need other developers to have exact copies of your data as long as they have all the other code.

We do that by editing .gitignore and adding the something like this:

# Ignore Fedora data files
/fcrepo4-data

Now commit this change

git add .gitignore
git commit -m "Adds /fcrepo4-data to .gitignore"

Step 4: Stop FCRepo and Solr

In order to stop either service, open the window they are running in and type <Control>-C. Wait a few moments for the process to terminate.

Tip: Sometimes people are confused about whether they need to restart Fedora or Solr when they restart their Rails application. In most cases it is fine to leave Fedora and Solr running when you start, stop, and restart the Rails application. The only exception is when you make changes to Solr's configuration or Fedora's configuration -- these would be changes to files inside of your copy of the solr configuration (i.e. solr/config), not changes to files in your Rails application's Ruby code. In those cases, where you have made changes to Solr or Fedora's configuration, you need to restart the processes in order for those changes to take effect. The most common change that requires restarting Solr is when you modify the solrconfig.xml or schema.xml in your solr config directory. Normally, changes to your data steams or models do not require restarts to Solr and Fedora because these changes are indexed dynamically by Hydra.

Notes for users of fcrepo4-vagrant

If you are using a virtual machine created with fcrepo4-vagrant notice that you don't need solr_wrapper or fcrepo_wrapper as the VM already comes with Tomcat, Solr, and Fedora.

Next Step

Go on to Lesson - Start the Application & Search for Results or return to the Dive into Hydra page.