We had an application sitting on top of Hadoop and got problems using jsch once we switched to java 7. Got this exception:
Upgrading to jsch-0.1.51 from jsch-0.1.49 fixed the issue for us, but then it got in conflict with hadoop's jsch version (we fixed this for us by jarjar'ing our jsch version).
So i think jsch got introduce by namenode HA (
HDFS-1623). So you guys should check if the ssh part is properly working for java7 or preventively upgrade the jsch lib to jsch-0.1.51!
Some references to problems reported: