Revert "Revert "use different thrift protocols and transports""

This reverts commit b840430e9058d3a84080669279f969b9e7bb8496.
Revert "Revert "Revert "use different thrift protocols and transports"""

This reverts commit 38d3e27af375e48d7c78099f4c8322233d0ddf56.
implement privileged locking so that buffer transports are de-prioritized when contending with reads