Real-time search is the ability to search for content immediately after adding/updating it. A typical scenario is that a user is performing some sort of add/update action on content, then the system is able to process the change fast enough so that if the user then searches for that immediately, they will always be able to see the latest changes applied. Near real-time search (often abbreviated to NRT) allows for a larger time window—most would say less than 5 seconds. This time window, however big or small it is, is also known as the index latency. Solr 4's commits are faster than before, and it has a new even faster soft commit ability. As a result, all apps can have NRT search, and with some tuning, some can commit so fast that you can reasonably say you have real-time search!

Here are a series of tips to consider in your quest for the holy grail of real-time search with Solr: