see CASSANDRA-3719. (planning to upgrade thrift after we branch 1.2.)
Thrift you are using has known memory leaks, some are fixed in 0.9. Can you explain benefits for end user to have intentionally delivered software with memory leaks?
If you care to link to the memory leak fixes we can evaluate whether the risk of upgrading to an untested Thrift late in the dev cyle is worth it.
There are no memory leak fixes committed to github after 0.9.0 was released. Closer inspection of thrift changelog shows that memory leaks fixed in 0.8 and 0.9 are not related to java server, but to C/C++. Interesting fix is THRIFT-1457 for shrinking memory buffers.
Unless Jira is out of date, THRIFT-1457 is not fixed in 0.9 either.
its not but since patch is trivial and you ship thrift library binary with cassandra, you can ship a patched one.