Solr can be set up to have multiple configurations and search indexes on the
same machine. Each configuration is called a Solr core. Having multiple cores
is useful when you want different applications or different versions of CKAN to
share the same Solr instance, each application can have its own Solr core so
each can use a different schema.xml
file. This is necessary, for example,
if you want two CKAN instances to share the same |solr| server and those two
instances are running different versions of CKAN that require different
schema.xml
files, or if the two instances have different |solr| schema
customizations.
Each |solr| core in a multicore setup will have a different URL, for example:
http://localhost:8983/solr/ckan_default http://localhost:8983/solr/some_other_site
This section will show you how to create a multicore |solr| setup and create your first core. If you already have a multicore setup and now you've setup a second CKAN instance on the same machine and want to create a second |solr| core for it, see :ref:`creating another solr core`.
Create the file
/usr/share/solr/solr.xml
, with the following contents:<solr persistent="true" sharedLib="lib"> <cores adminPath="/admin/cores"> <core name="ckan_default" instanceDir="ckan_default"> <property name="dataDir" value="/var/lib/solr/data/ckan_default" /> </core> </cores> </solr>
This file lists the different Solr cores, in this example we have just a single core called
ckan_default
.Create the data directory for your Solr core, run this command in a terminal:
sudo -u jetty mkdir /var/lib/solr/data/ckan_default
This is the directory where Solr will store the search index files for our core.
Create the directory
/etc/solr/ckan_default
, and move the/etc/solr/conf
directory into it:sudo mkdir /etc/solr/ckan_default sudo mv /etc/solr/conf /etc/solr/ckan_default/
This directory holds the configuration files for your Solr core.
Replace the
/etc/solr/ckan_default/schema.xml
file with a symlink to CKAN'sschema.xml
file:sudo mv /etc/solr/ckan_default/conf/schema.xml /etc/solr/ckan_default/conf/schema.xml.bak sudo ln -s /usr/lib/ckan/default/src/ckan/ckan/config/solr/schema.xml /etc/solr/ckan_default/conf/schema.xml
Edit
/etc/solr/ckan_default/conf/solrconfig.xml
and change the<dataDir>
tag to this:<dataDir>${dataDir}</dataDir>
This configures our
ckan_default
core to use the data directory you specified for it insolr.xml
.Create the directory
/usr/share/solr/ckan_default
and put a symlink to theconf
directory in it:sudo mkdir /usr/share/solr/ckan_default sudo ln -s /etc/solr/ckan_default/conf /usr/share/solr/ckan_default/conf
Restart Solr:
|restart_solr|
You should now see your newly created
ckan_default
core if you open http://localhost:8983/solr/ckan_default/admin/ in your web browser. You can click on the schema link on this page to check that the core is using the right schema (you should see<schema name="ckan" version="2.0">
near the top of theschema.xml
file). The http://localhost:8983/solr/ page will list all of your configured Solr cores.Finally, change the
solr_url
setting in your |development.ini| or |production.ini| file to point to your new Solr core, for example:solr_url = http://127.0.0.1:8983/solr/ckan_default
If you have trouble when setting up Solr, see :ref:`multicore solr troubleshooting` below.
In this example we'll assume that:
- You've followed the instructions in :ref:`multicore solr setup` to create a multicore setup and create your first core for your first CKAN instance.
- You've installed a second instance of CKAN in a second virtual environment at /usr/lib/ckan/my-second-ckan-instance, and now want to setup a second Solr core for it.
You can of course follow these instructions again to setup further Solr cores.
Add the core to
/usr/share/solr/solr.xml
. This file should now list two cores. For example:<solr persistent="true" sharedLib="lib"> <cores adminPath="/admin/cores"> <core name="ckan_default" instanceDir="ckan_default"> <property name="dataDir" value="/var/lib/solr/data/ckan_default" /> </core> <core name="my-second-solr-core" instanceDir="my-second-solr-core"> <property name="dataDir" value="/var/lib/solr/data/my-second-solr-core" /> </core> </cores> </solr>
Create the data directory for your new core:
sudo -u jetty mkdir /var/lib/solr/data/my-second-solr-core
Create the configuration directory for your new core, and copy the config from your first core into it:
sudo mkdir /etc/solr/my-second-solr-core sudo cp -R /etc/solr/ckan_default/conf /etc/solr/my-second-solr-core/
Replace the /etc/solr/my-second-solr-core/schema.xml file with a symlink to the
schema.xml
file from your second CKAN instance:sudo rm /etc/solr/my-second-solr-core/conf/schema.xml sudo ln -s /usr/lib/ckan/my-second-ckan-instance/src/ckan/ckan/config/solr/schema.xml /etc/solr/my-second-solr-core/conf/schema.xml
Create the /usr/share/solr/my-second-solr-core directory and put a symlink to the
conf
directory in it:sudo mkdir /usr/share/solr/my-second-solr-core sudo ln -s /etc/solr/my-second-solr-core/conf /usr/share/solr/my-second-solr-core/conf
Restart |solr|:
|restart_solr|
You should now see both your Solr cores when you open http://localhost:8983/solr/ in your web browser.
Finally, change the :ref:`solr_url` setting in your /etc/ckan/my-second-ckan-instance/development.ini or /etc/ckan/my-second-ckan-instance/production.ini file to point to your new Solr core:
solr_url = http://127.0.0.1:8983/solr/my-second-solr-core
If you have trouble when setting up Solr, see :ref:`multicore solr troubleshooting`.
Multicore |solr| setup troubleshooting
.. seealso:: :ref:`Troubleshooting for single-core Solr setups <solr troubleshooting>` Most of these tips also apply to multi-core setups.
No cores shown on |solr| index page
If no cores are shown when you visit the |solr| index page, and the admin
interface returns a 404 error, check the web server error log
(/var/log/jetty/<date>.stderrout.log
if you're using Jetty, or
/var/log/tomcat6/catalina.<date>.log
for Tomcat). If you can find an error
similar to this one:
WARNING: [iatiregistry.org] Solr index directory '/usr/share/solr/iatiregistry.org/data/index' doesn't exist. Creating new index... 07-Dec-2011 18:06:33 org.apache.solr.common.SolrException log SEVERE: java.lang.RuntimeException: Cannot create directory: /usr/share/solr/iatiregistry.org/data/index [...]
Then dataDir
is not properly configured. With our setup the data directory
should be under /var/lib/solr/data
. Make sure that you defined the correct
dataDir
in the solr.xml
file and that in the solrconfig.xml
file
you have the following configuration option:
<dataDir>${dataDir}</dataDir>