in crossdc-consumer/src/main/java/org/apache/solr/crossdc/messageprocessor/SolrMessageProcessor.java [152:157]
private void logIf4xxException(SolrException solrException) {
// This shouldn't really happen but if it doesn, it most likely requires fixing in the return code from Solr.
if (solrException != null && 400 <= solrException.code() && solrException.code() < 500) {
log.error("Exception occurred with 4xx response. {}", solrException.code(), solrException);
}
}