I know this is a huge change. But here goes the suggestion: migrate the portal to the new HttpClient 4.x (http://hc.apache.org/httpcomponents-client-ga/)
Apache says that it has some good performance (and other) improvements: http://www.apache.org/dist/httpcomponents/httpclient/RELEASE_NOTES-4.1.x.txt
The problem is that the way to perform connections is now quite different. So a lot of thinks will need to be reimplemented. But in the other side, the package structure is different, so it will be possible to do this migration step-by-step and keep the portal backward compatible.