The <response/> element wraps the entire response. The first child element is <lst name="responseHeader">, which is intuitively the response header that captures some basic metadata about the response. Some of the fields you'll find in the responseHeader include:
status: This is always0. If a Solr error occurs, then the HTTP response status code will reflect it and a plain HTML page will display the error.QTime: This refers to the number of milliseconds Solr takes to process the entire request on the server. Due to internal caching, you should see this number drop to a couple of milliseconds or so for subsequent requests of the same query. If subsequent identical searches are much faster, yet you see the sameQTime, then your web browser (or intermediate HTTP proxy) has cached the response. Solr's HTTP caching configuration will be discussed in Chapter 10, Scaling Solr.Other data may be present depending on query parameters.
The main body of the response...