I wrote a Python multi-threaded server, specific business logic is
The main thread to create the sock socket that handle the message box
Create a thread into a listening socket and wait for the connection,
For each socket connection, will cause a thread to wait for receive the news, and in a message box,
Other threads wait for a message from the message box, send,

I am currently in the pressure test, test found that the number of connections can only be reached around 300, after more than a server error below,

Do you have any bosses to see what situation