Look into how HttpSolrCall#remoteQuery handles IOException and passing error messages back to a client.
Specify the entity request size when known in HttpSolrClient.
Successful or not, requests are not always fully consumed by Solrj clients and we count on HttpClient or the JVM.
SolrJ code review indicates potential for leaked HttpClient connections
Jetty update from 9.2 to 9.3 causes the server to reset formerly legitimate client connections.
Upgrade Jetty from 9.2 to 9.3