private void process() throws IOException, InterruptedException {
    data.rewind();
    try {
      if (skipInitialSaslHandshake) {
        skipInitialSaslHandshake = false;
        return;
      }

      if (useSasl) {
        saslReadAndProcess(data);
      } else {
        processOneRpc(data);
      }
    } catch (Exception e) {
      callCleanupIfNeeded();
      throw e;
    } finally {
      dataLengthBuffer.clear(); // Clean for the next call
      data = null; // For the GC
      this.callCleanup = null;
    }
  }
Process the data buffer and clean the connection state for the next call.
hbase-server/src/main/java/org/apache/hadoop/hbase/ipc/SimpleServerRpcConnection.java