grpc channel close problem

Because don't log close error, so not knowing the root cause, but can has some doubt

when fields too much, seems like that the channel is closed.

maybe due to msg size!

solution：add logInfo when fail；

make eventset number per vector configurable？但是用户也不清楚多大好，最好是自适应地调整，调整到最适合网络传输的大小（是否有相关文献）& 不超过最大wire size（应该把wire size设置为最适宜的大小吧，这个可以让用户配置，目前就是用户设置，所以最好还是保持这个操作，让用户控制）

should make reader receive maxSize configurable？