This avoids the problem of congesting the network channel with non-critical resources when a high-priority request is pending.
在有高优先级的请求等待时,该功能可以避免让非关键资源占用网络通道的问题。
2
The caller can't just put any request message format on any requestchannel; it has to know exactly the right message format and channel for the specific service it wishes to invoke.