The strange problem of ServerSocket and ClientSocket

史提芬周

In the local area network, there are currently three clients (for development and testing) at most nine, long connection, large amount of data, fixed packet structure but variable length, D7+SERVERSOCKET and CLIENTSOCKET server and client are asynchronous.

Process: The client may generate data at any time. After the data is generated, it is uploaded to the server, and the server parses and writes the library after receiving it (the maximum time is no more than 1 second). Then issue a processing completion notification. The client continues to upload after receiving it.

The problem now is that after running for a period of time (one to two hours, or maybe three hours), there will be problems, or the service cannot receive the data uploaded by the client, or the client cannot receive the processing of the server. Complete notification. Do not know what's going on?

darkfire1986

Is it not connected? Use netstat -an to check the connection status on the command line

goylee

Usually use Indy's~

wwutian

Long connection is not keeping the connection. You should close the connection after transmitting a set of data and re-establish the connection with the new data. This situation is unavoidable.

史提芬周

There should be no problem with the connection, because after a problem, if it cannot be received, it can be sent. If it cannot be sent, it can be received. This should indicate that the connection is not broken
I don’t want to change INDY now, I just want to know what’s going on
It’s not feasible to close this after the data has been transmitted. My system is real-time. There may be data at any time, which will cause continuous connection closures.

skgame

It seems that this kind of situation is prone to occur when socket is not communicating for a long time. You can use a timer. When there is no interaction for a long time, send a non-existent information data to each other every 10 minutes. Try

史提芬周

Dizzy, it’s not that there is no interaction for a long time, but it’s been interacting all the time, and data is always being transmitted
During normal transmission, it suddenly becomes abnormal. . .

dylnnet

attention!

sirbogard

I also have this problem here. There are about 5-7 clients that are quite fast at the beginning. It took 3-4 hours and then slowed down. And the memory gradually increased, reaching 900M, and finally died!

狼三少

It is estimated that there is an error on the server side, the server side is congested, and the data reaches the TCP cache of Windows, but the upper layer data is not processed. It may be that on the server side, you are not using event-driven programming, but actively receiving data. When the client sends data congestion, the subsequent data is incorrectly processed, causing the server to wait for a long time when analyzing the data according to the structure, causing further data congestion.