Solr

This is the answer and explanation to the Solr puzzle on what happens during indexing, using a date as an example. In this blog post, we will dig into the complex and fascinating details of what those three simple commands cause behind the scenes. So, let’s start from getting the server up and running. This example is based on Solr 5.5, though it should work in 6.0 the same. This starts the server.

(This is the final part of the explanation for the Solr puzzle that brings together schemaless mode, dates and other automagical parts of Solr. See the puzzle post for the setup and the 1st part of the answer for explanations of why 3 out of 5 answer choices were not valid) By now, we are facing a basic binary choice. In summary, given a schemaless configuration, we indexed a new field today with a value 2016-04-18, which got parsed as a date 2016-04-08T00:00:00Z.

From the SolrStart newsletter issue #30: Given the following sequence of commands: Would the result be: Error in the command 1 for not providing a configuration directory Error in the command 2 for missing a uniqueKey field Error in the command 2 due to an incorrect date format No records in the command 3 output One record in the command 3 output For answer and detailed explanation, subscribe to the SolrStart newsletter.

A question was asked on the Solr Users mailing list on how to assess a comprehensive list of Solr features. It is an interesting question, as Solr is like a balloon being blown up. It is expanding in all directions. It is unlikely that one person will be able to comprehend all the features before the next release adds some extra. Solr is definitely not a slow tortoise when it comes to competing with hares. Especially when it is the tortoise that decides in which direction the goal lies.

Still, there must be a way to approach that state of knowledge, however asymptotically.  Here would be mine, which comes from the practice of writing a Solr book as well as numerous Solr training materials.

Ever started a Solr (5.x) with an example, stopped it and then could not figure out where that example actually lives? I certainly have.

This did not used to be a problem in Solr 4.x because you started the instance manually and were forced to know where your Solr home directory was (with solr.solr.home property). And they were all in the example directory out of the box anyway. But with Solr 5, we now have startup scripts, examples, and startup configurations which make things easier to get going, but may also introduce some confusion down the road.

So, this is a compilation of all the examples Solr 5.3 ships with, what configs they are using and where the startup scripts create homes for them. Plus a couple of weird related things.

Let’s start from starter configurations. Every Solr collection has one, and several examples use the same configuration.

Solr ships with three configurations, you can see the list if you run bin/solr create_core -help. Those configurations are: