Solr in a multi-tenant environment

I am considering using Solr in a multi-tenant application and I am wondering if there are any best practices or things I should watch out for?

One question in particular is would it make sense to have a Solr Core per tenant. Are there any issues with have a large number of Solr Cores? I am considering use a core per tenant because I could secure each core separately.

Thanks

Solr Cores are an excellent idea for multitenant, particularly as they can be managed at runtime (so not requiring a server restart). You shouldn't run into too many problems with performance for having multiple Solr cores, but be aware the performance of one core will be impacted by the work on other cores - they're probably going to be sharing the same disk.

I can see why you might want to give direct API access - for example if each 'user' is a Drupal site or similar, for a shared hosting type environment. The best thing would be to secure the different URLs, e.g. if you had /solr/admin/cores, /solr/client1 for a client core, and /solr/client2 for another, you would have three different authentications, one for your admin, and one each for your tenants. This is done in the container (Jetty, Tomcat etc.), take a look at the general Solr Security page: http://wiki.apache.org/solr/SolrSecurity - you'll want to setup a basic access login for each path in the same way.

You would no more use a separate table in a database for each tenant than you would a solr core for each tenant.

If you think of a core like a database table and organize your project in such a way that each core represents an object in your problem space then you can better leverage solr.

Where solr shines in when you need to index text and then search it quickly. If you are not doing that you might as well use a relational database.

Also from your question about securing solr for each tenant , I hope you're not suggesting allowing your logged in users to access the solr output directly? Your users should not be able to directly access your solr instance.

Good luck.

That's OK .. you can not use cache(inbuild) properly and for your requirements. You add permission bit in which you can change the query component in which you can. It should work properly according to the permission. There is a bitwise operation also available for this. Make use of this for your needs.