We are currently having problems with the MKS API (mksapi.jar) and the jenkins plugin.
After spending some days figuring out what's wrong, we finally found that the plugin (and or mksapi) opens many file handles without closing them. This leads to the MKS Integrity Server not being able to open any more file handles and becoming unusable even with the GUI client.

The mksapi seems to open a separate socket for each file checkedout and so consumes over many thousands of file handles on the server. This might be an issue with the old httpclient library used.