impala断开连接后释放session

代码在这里 https://github.com/cloudera/Impala/blob/cdh5-2.2.0_5.4.0/be/src/service/impala-server.cc   如果不想断开清除session,直接return

void ImpalaServer::ConnectionEnd(
    const ThriftServer::ConnectionContext& connection_context) {
  return;
  unique_lock<mutex> l(connection_to_sessions_map_lock_);
  ConnectionToSessionMap::iterator it =
      connection_to_sessions_map_.find(connection_context.connection_id);

  // Not every connection must have an associated session
  if (it == connection_to_sessions_map_.end()) return;

  LOG(INFO) << "Connection from client " << connection_context.network_address
            << " closed, closing " << it->second.size() << " associated session(s)";

  BOOST_FOREACH(const TUniqueId& session_id, it->second) {
    Status status = CloseSessionInternal(session_id, true);
    if (!status.ok()) {
      LOG(WARNING) << "Error closing session " << session_id << ": "
                   << status.GetDetail();
    }
  }
  connection_to_sessions_map_.erase(it);
}