Solr 5 introduced a lot of changes to the world of the API’s and functionalities around Solr. JSON API and facets were the one that were moved from HeliosSearch project and resulted in users being able to send queries using JSON, which is a bit more human friendly compared to long queries constructed as URI. In this post we will introduce you to the world on JSON request API in Solr.
In case our collection is very large (or there are a few of them) in a case when full replication is needed, Solr can use all the bandwidth of our network (if the disks are fast enough). This is good in some situations, but bad in others. Imagine that you have some collections being queried and of them starts to replicate a tens of gigabytes of data – all the other collections would suffer. Thankfully with the release of Solr 5 we got replication throttling and we can use it to limit the amount of data allowed to be transferred by Solr.